RC(U)6 Installation and Maintenance Manual - Marine Refrigeration ...

RC(U)6 

Installation and Maintenance Manual 

00.89.238 v004.00.02.en

Refrigeration Division 

Grasso 

All rights reserved. No part of this publication may be copied or published by means of printing, 

photocopying, microfilm or otherwise without prior written consent of Grasso. This restriction 

also applies to the corresponding drawings and diagrams. 

For extra information as to adjustments, maintenance and repair, contact the Technical 

Departmentof your supplier. 

This publication has been written with great care. However, Grasso cannot be held responsible, 

neither for any errors occurring in this publication nor for their consequences. 

Installation and Maintenance Manual RC(U)6 v001.99.01.en


Grasso 

1. Document Information 

• This ’lnstallation and Maintenance manual’ will 

be supplied together with the compressor. 

• This manual is suitable for both end-user and 

contractor and will provide information on how 

to transport, install, start-up and maintain the 

compressor (package). It also contains a number 

of "Engineering Data Sheets" and the current 

"Parts List". 

2. Additional Documentation 

In addition to the above the following is available 

for this series compressor: 

• Engineering Data Sheets Book; 

This book contains all engineering data for this 

series compressor and the corresponding 

recommended accessories. It is meant to be a 

guide to the selection of these components. 

• Parts book; 

This book contains all current parts of the 

compressor and accessories together with the 

design changes applicable to earlier supplied 

components ("History"). 

• Mounting and Installation Instructions for 

Accessories; 

If compressor is supplied with accessories, all the 

relevant mounting and installation instructions 

and spare parts information for those 

accessories will be supplied together with the 

compressor. 

PREFACE 

v001.99.01.en Installation and Maintenance Manual RC(U)6 V


Grasso 

PREFACE 

VI Installation and Maintenance Manual RC(U)6 v001.99.01.en


This manual must be carefully read and 

understood prior to installing the 

compressor (package) 

Installer-oriented information 

The compressor (package) is filled with nitrogen to 

prevent penetration of moisture. Therefore, keep 

the compressor closed until the compressor 

(package) is being installed. The compressor is not 

filled with oil. How to charge the compressor 

package with oil is discussed in Section A, §A2.3, 

"Initial oil charge". 

After the succesful initial run of the compressor 

(package) the warranty chart must be filled in and 

returned to Grasso. A warranty chart is attached 

to each compressor. 

Safety 

This manual is written with great care, but the 

contractor/installer is held responsible to examine 

this information and to care of possible additional 

and/ or deviated safety measures. 

Safety instructions 

It is the task of the contractor/installer to inform 

and explain his client about the operation of the 

compressor (Package). 

Do respect all federal, state or local safety 

regulations/legislations during installing, 

connecting and operating this compressor 

(package). 

Typographic signs: 

Grasso 

Indicates a caution, note or procedure to 

which you should pay special attention. 

Read it carefully! 

Values Between [ ] 

Values between [ ] are read-outs of Grasso’s 

electronic control device Monitron. 

GENERAL SAFETY INSTRUCTIONS 

v001.99.01.en Installation and Maintenance Manual RC(U)6 VII


Grasso 

GENERAL SAFETY INSTRUCTIONS 

VIII Installation and Maintenance Manual RC(U)6 v001.99.01.en


General information 

Grasso 

Operating limits and switch settings 

(for values between [ ] brackets refer to the Instruction Manual of the Monitron) 

Timers Time interval refer to chapter: 

Switching frequency max. 6 starts per hour A2.10.1 

Time interval between stopping and re-starting min. 2 minutes A2.10.2 

Time interval between starting and re-starting min. 10 minutes A2.10.2 

Time interval between unloading and loading min. 3 minutes B1.2 

Oil system limits Value 

Oil level 25 - 75% crankcase sight glass B4 

Min. oil temperature warmer than surroundings and ≥ 20 °C (68 °F) 

for NH3 and ≥ 30 °C (86 °F) for halocarbons 

A2.8 

Max. oil temperature [max. Toil] see oil selection table in the appendix section B1.2 

Lubricating oil pressure difference [min dOil] between 1.5 and 2.5 bar 

Setting approx. 1.8 bar 

A2.5.2 

Temperature and pressure limits Value 

GENERAL INFORMATION AND SURVEY 

OF SETTINGS AND LIMITS 

Max. discharge temperature [max Tdis] 155 °C (311 °F) B1.2 

Pdischarge - Psuction < 24.0 bar 

Superheat [dTo] ≥ 5 K 

Cooling water inlet temperature of cylinder 

head cooling system 

≥Tcond + 10 K 

Pressure safety limits A2.5.2 

Subject Feature refer to chapter: 

Oil viscosity ≥ 10 cSt during operation at location of bearings 

Direction of rotation of compressor drive shaft Counterclockwise when facing shaft end A2.6 

v001.99.01.en Installation and Maintenance Manual RC(U)6 IX


Grasso 

GENERAL INFORMATION AND SURVEY 

OF SETTINGS AND LIMITS 

X Installation and Maintenance Manual RC(U)6 v001.99.01.en


Grasso 

SUBJECT Page no.: 

PREFACE ............................................................................................................................... V 

GENERAL SAFETY INSTRUCTIONS ................................................................................................. VII 

GENERAL INFORMATION AND SURVEY OF SETTINGS AND LIMITS .......................................... IX 

SECTION A: INSTALLATION AND PREPARATIONS FOR USE ....................................................... A1.1 

A1 INSTALLATION .......................................................................................................................... A1.1 

A1.1 Moving instructions and storage ................................................................................. A1.1 

A1.1.1 Hoisting and moving instructions ...................................................................... A1.1 

A1.1.2 Storage ............................................................................................................... A1.2 

A1.2 Required free space ....................................................................................................... A1.2 

A1.3 Foundation requirements .............................................................................................. A1.2 

A1.3.1 Concrete structure ............................................................................................. A1.3 

A1.3.2 Anchoring ........................................................................................................... A1.4 

A1.4 Concrete block mounting instructions .......................................................................... A1.4 

A1.4.1 Mounting bare compressor on a concrete block ............................................. A1.4 

A1.4.2 Mounting the base frame on a concrete block ................................................ A1.4 

A1.5 Connecting to refrigerating system pipework ............................................................. A1.5 

A1.6 Connecting the power supply ....................................................................................... A1.6 

A1.7 Earthing connections ..................................................................................................... A1.6 

A1.8 Separately delivered components.................................................................................. A1.6 

A2 PREPARATIONS FOR USE ......................................................................................................... A2.1 

A2.1 Leak test of compressor and system ............................................................................. A2.1 

A2.2 Evacuation/drying the refrigerating system ................................................................. A2.1 

A2.3 Initial oil charge .............................................................................................................. A2.1 

A2.4 Initial refrigerant charge ................................................................................................ A2.2 

A2.5 Adjustment of instruments and safety devices ............................................................ A2.2 

A2.5.1 Monitron ............................................................................................................. A2.2 

A2.5.2 Pressure safety switches ..................................................................................... A2.2 

A2.5.3 Re-adjustment of oil pressure regulator ........................................................... A2.3 

A2.6 Checking direction of rotation of motor shaft ............................................................. A2.4 

A2.7 Installing the (drive) guards .......................................................................................... A2.4 

A2.8 Initial oil warm-up .......................................................................................................... A2.4 

A2.9 Initial start-up ................................................................................................................. A2.4 

A2.9.1 Limitations part load operation and start-up.................................................... A2.4 

A2.9.2 Pre-start check list .............................................................................................. A2.4 

A2.10 Starting and stopping procedures ................................................................................ A2.4 

A2.10.1 Starting for the very first time ......................................................................... A2.4 

A2.10.2 Restart .............................................................................................................. A2.5 

A2.10.3 Starting after a seasonal (1 till 6 months) standstill or maintenance operations A2.5 

A2.10.4 Starting after a long standstill periode of time (more than 6 months) ........ A2.5 

A2.10.5 Stopping the compressor ................................................................................. A2.5 

SECTION B: INSPECTION, MAINTENANCE AND TROUBLE SHOOTING: .Table of contents ....... B.I 

SECTION C: APPENDIX : .......Table of contents ...... C.I 

SECTION D: STANDARD ILLUSTRATED SPARE PARTS LIST: ....................Table of contents ....... D.I 

For oil selection table refer to "Engineering Data" 

TABLE OF CONTENTS 

v001.99.01.en Installation and Maintenance Manual RC(U)6 III


Grasso 


IV Installation and Maintenance Manual RC(U)6 v001.99.01.en


The compressor is not charged with oil, 

therefore, DO NOT start the compressor 

before it has been installed and prepared 

according to the sections A1 and A2. 

A1 INSTALLATION 

Grasso 

This section contains instructions for the proper 

installation of a Grasso compressor (package). 

Before the compressor (package) is ready for the 

initial start up, the installation instructions in the 

following paragraphs must be followed: 

1. The Compressor (Package) should be levelled and 

securely anchored to the foundation (see §A1.4). 

2. All piping should be completed as in §A1.5. 

3. The system and the compressor are to be pressure 

tested for leaks (see §A2.1). 

4. The system should be evacuated to remove air and 

moisture (see §A2.2). 

5. The electric wiring should be completed as per 

wiring diagrams. Do not energize the main power 

control cabinet until oil is added and the direction 

of rotation has been checked. 

6. The compressor is to be filled with the correct type 

and amount of lubricating oil (see §A2.3). 

7. The drive coupling or V-belt drive system should be 

installed. 

8. The system should be charged with the correct 

amount of refrigerant. 

9. The oil should be warmed up above minimum start 

up oil temperature (see "Engineering Data"). 

10. The control cabinet or Monitron CR should be 

energized to check the package control 

(see §A2.5). 

A: INSTALLATION AND PREPARATION FOR USE 

A1.1 Moving instructions and storage 

For loose component or compressor package 

weights, refer either to the relevant component 

type plate or package lay-out or to the suppliers 

document. For bare compressor weights, see 

"Engineering Data". 

Every precaution must be taken while 

moving the package to its final location. 

Pushing, pulling or climbing on any 

package component or piping, can easily 

create damage. 

A1.1.1 Hoisting and moving instructions 

Fig. A1.1 Hoisting a compressor-package 

Packaged base frame: 

The only places that can be used for safe hoisting 

of the package are the four hoisting eyes on the 

steel base frame as shown in the above figure. 

Prior to hoisting a compressor package with a 

V-belt drive arrangement, the factory mounted 

drive guard has to be removed. Attach spreader 

bars to the slings so as to prevent damage to 

piping and components. 

DO NOT use the component hoisting 

eyes to move the package! 

These hoisting eyes are intended for 

lifting loose components only and not for 

the entire package! 

v001.99.01.en Installation and Maintenance Manual RC(U)6 A1.1


Grasso 

Bare compressor or loose components: 

Determine the dead weight of the particular 

component (see "Engineering 

Data"), prior to moving a bare compressor 

or loose component. Use the hoisting 

eyes only to lift so, DO NOT sling 

from other compressor parts (see figure 

A1.1A). 

Fig. A1.1A Hoisting angle bare shaft compressor 

Moving by fork-lift truck 

The bare compressor or package can be 

transported with a fork-lift truck with the forks 

spread as much as possible between the skids. To 

simplify moving, the 2 wooden transport beams 

must still be mounted underneath the base frame 

and stored in this way, untill the package is 

positioned above its approximate location. 


A1.1.2 Storage 

The compressor (package) is filled with dry 

nitrogen. Keep the system closed until the 

package is 

installed. If the compressor (package) is stored, it 

should be kept at all times in a dry location to 

prevent corrosion damage. If the compressor 

(package) is to be stored for a prolonged period 

of time, it should be checked weekly to ensure 

that the holding charge of dry nitrogen remains 

above atmospheric pressure. 

A1.2 Required free space 

For easy operating, servicing and maintenance 

access, the compressor (package) should be at 

least installed with sufficient free space around it. 

A1.3 Foundation requirements 

This paragraph covers measures to be taken for a 

compressor (package) on a concrete floor. 

Two foundation arrangements are described: 

• Compressor package with steel base frame 

mounted on a concrete block. 

• Bare compressor direct mounted on a concrete 

block via grouted machined anchors (see 

"Engineering Data"). The mounting surfaces of 

these machined anchors must be level without 

any deviation and projecting at least 10 mm 

above the concrete base. 

COMPRESSOR AND COMPRESSOR 

PACKAGE TO BE MOUNTED ON A 

CONCRETE BLOCK 

On request, Grasso can calculate the 

exact dimensions of the concrete block, 

based on the compressor size and 

operating conditions. 

A1.2 Installation and Maintenance Manual RC(U)6 v001.99.01.en


A1.3.1 Concrete structure 

The concrete block for compressor and motor or 

compressor package should have a profile as 

illustrated in fig. A1.2 and made according to the 

following recommendations: 

Fig. A1.2 

Grasso 

1 Corkboard 

2 Concrete base 

3 Basement floor 

• The concrete block should be set on firm 

footings or on a floor capable of carrying the 

weight of the concrete block and capable to 

absorb the free forces and gas forces of the 

compressor during operation. The ground under 

the concrete block should be horizontal and flat 

(refer to fig. A1.2). 

• The top surface of the block should be level and 

even. 

• There should be sufficient free space around the 

block to install corkboard (or similar). 

• The block should be provided with anchor bolt 

recesses or holes (fig A1.3.) according to the 

anchor bolt spacing as per package lay out 

drawing. 


A Chemical anchor 

B Grouted anchor, grounded to reinforcing steel 

Fig. A1.3 

It is recommended to consult a concrete specialist/ 

constructor for the following items: 

• The compounding of the concrete with/without 

reinforcement. 

• The exact grouting depth (dependent on the 

soil conditions). 

• Installing foundation onto an existing floor, with 

sealing corkboard or vibration isolators. 



A1.3.2 Anchoring 

Grasso 

After the concrete block has cured the anchors 

should be installed as shown in figs. A1.3 and/or 

A1.4 and in case of a package in accordance with 

the package lay out drawing. Templates should be 

made to locate the anchor bolts or chemical 

anchors to match the holes in the bottom flange 

of the base frame. 

Grout the mortar as given by the supplier 

instructions. Install chemical anchors as illustrated 

in figure A1.4 and according the instructions of 

the anchor supplier. 

A Drilled chemical anchor (thread size M16) 

B Grouted anchor recesses (thread size M16) 

Fig. A1.4 Anchoring details 

A1.4 Concrete block mounting instructions 

A1.4.1 Mounting bare compressor on a concrete 

block 

If no base frame is applied the compressor and 

motor should be installed as discussed in §A1.3 

and "Engineering Data". 


1 Installed chemical anchor before placing the base frame 

2 Installing chemical anchor after placing the base frame (base 

frame cannot removed easily) 

3 Drilling angle 

A1.4.2 Mounting the base frame on a concrete 

block 

General 

After the space between base frame and concrete 

base is filled-up with a filling grout, the package 

base frame must be secured tightly to the 

foundation block or floor (refer to fig. A1.3). 



Grasso 

Fig. A1.5 Grouting details 

• Levelling the base frame 

After the anchor filling mortar is completely cured 

the frame should be levelled with a space 

between block and lower frame flange of 3 - 5 

mm. This space largely depends on the sort of 

grout or mortar used. Determine this space as 

given in the instructions of the grout or mortar 

supplier. This space is necessary for levelling using 

the base frame adjusting bolts with metal washers 

(supplied separately). The base frame should be 

levelled on each frame side. Adjust the frame on 

each adjusting place until all frame sides are 

horizontal. 

• Finishing with a self-levelling grout (See figure A1.5) 

After levelling is completed the adjusting bolt 

ends must be greased to avoid bonding to the 

self-levelling grout. The space between concrete 

block and frame must be completely filled with 

the self-levelling grout to ensure that the 

complete bottom surface of the base frame will 


1 Self-levelling grout 

2 Adjusting bolt (4x) 

3 Washer 

4 Temporary barrier strip around and inside frame 

5 Complete cured concrete block 

6 Grout layer 

be supported. Therefore, it is not allowed to use 

shims between concrete base and base frame. 

Grouting must be carried out in accordance with 

the instructions provided by the grouting supplier. 

After complete de-aeration of the grouted layer, 

secure the base frame by tightening the anchor 

bolt nuts and remove all adjusting bolts. At this 

stage the drive system can be installed. These 

(accessories) installation instructions can be found 

in the order manual. 

A1.5 Connecting to refrigerating system pipework 

After the compressor (package) has been levelled 

and secured to the foundation, the system piping 

may be connected. The suction line(s) and 

discharge line(s) should be installed and supported 

such that there is no load exerted on the 

compressor. The size and location of the suction 

and discharge connections, can be found in the 

"Engineering Data" (bare compressor) and in case 

of a package, the package lay out drawing. 



Grasso 

If an oil rectifier system is applied in the refrigeration 

system, the oil return line 

must be connected to the oil return connection. 

Never connect the oil rectifier return line to 

the suction line or to the suction gas filter. 

DO NOT ground through the compressor 

when arc welding 

Suspension of system pipework 

To eliminate vibration transmission to the system 

piping, the following is recommended: 

• Install all piping free of tension. 

• Secure the piping by clips or suspenders in two 

directions. 

• Install (stop) valves, piping and accessories such, 

that there is no load exerted on the compressor. 

A1.6 Connecting the power supply 

Before leaving the factory the compressor 

package is completely wired*. The connection to 

be made by the installer is between main power 

source and the Monitron CR (if ordered). 

Information about further electrical connections 

to be made (e.g. crankcase heater, drive motor 

starting equipment, thermal protection of drive 

motor, automatic start/ stop, motor current 

transducer and other external electrical devices) 

can be found in the order manual. 

* If the standard recommended Monitron CR is applied. 


A1.7 Earthing connections 

Grasso compressors and packages are equipped 

with litz-wires and earth connecting points. 

To avoid leakage current flowing through the 

components, disconnect all litz-wires when arcwelding. 

After all installation functions are 

completed, reconnect the litz-wires and ground 

the package to earth. 

A1.8 Separately delivered components 

Mount the separately delivered set-components 

e.g. oil charge and drain valve, according to the 

instruction enclosed in each individual set. 



Grasso 

A2 PREPARATIONS FOR USE 

After the Compressor (Package) has been installed 

(excl. final connection of drive device), the 

following actions should be followed in the order 

given: 

A2.1 Leak test of compressor and system 

The compressor (package) has been pressure 

tested prior to leaving the factory. In case an 

additional leak test is required, this test is should 

be carried out with dry nitrogen under pressure 

up to a max. of 10 bar(a). 

Do NOT add oil to the compressor prior 

to pressure testing. 

A system leak test should be carried out over 24 

hours to ensure that the system is tightly sealed. 

Record during the pressure test, the pressure, 

ambient temperature and outside temperature. 

During the initial 6 hours a pressure drop of 2% is 

permissable. With respect to temperature 

variations, no further pressure loss should be 

detected in the remaining 18 hours. 

If the test pressure has not decreased by more 

than 5% the system can be considered leak free. 

A2.2 Evacuation/drying the refrigerating system 

For evacuation of compressor only, refer to §B5. 

Procedure to evacuate and to dry a system: 

a) STATUS: System is filled with nitrogen (refer to 

§A2.1) and no oil into the system (oil prevents any 

trapped moisture from boiling off). 

b) Verify that all valves in that part of the system to be 

evacuated are opened (refer also to the plant 

manual). 

c) Connect vacuum pump to the evacuation/purging 

valve(s) of the compressor (for location of these 

valves refer to the "Engineering Data" or to a 

connection as mentioned in the plant manual and 

evacuate the system to approx. 

5 mm Hg (=6.6 mBar). 

A: INSTALLATION AND PREPARATIONS FOR USE 

d) Break vacuum by charging dry nitrogen into the 

system. 

e) Repeat step ’c’. 

f) Wait approx. 24 hours. 

g) If pressure has been increased (system still contains 

moisture), repeat steps ’d’, ’e’ and ’f’, otherwise, 

continue with the "Initial oil charge" procedure 

§A2.3. 

A2.3 Initial oil charge 

Used or filtered oil should NEVER BE 

added to a compressor under any 

circumstance. 

Use only new oil to be selected from the 

oil table (see "Engineering Data"). 

a) STATUS: System is dried and still evacuated (refer to 

§A2.2). 

b) Close suction and discharge stop valves of 

compressor and oil return line of oil separator 

(if present). 

c) Fill the compressor crankcase with oil (for oil 

quantity see table overleaf) via the oil charge/ drain 

valve (for location of this valve refer to the 

"Engineering Data"). 

d) Open evacuation/purging valve(s) of the 

compressor (for location of these valves refer to the 

"Engineering Data") to bring the compressor to 

atmospheric pressure. 

e) Fill the following components with oil as given in 

the table on the next page with/without prelubrication 

valves (explained hereafter) : 

- Shaft seal housing via the oil filling opening. 

- Oil pump housing via the oil filling opening. 

- Oil suction and discharge filter housings via the oil 

filling openings. 



A2.4 Initial refrigerant charge 

Refrigerant charging should be done in 

accordance to the plant manual by qualified 

refrigeration engineers. 

Oil charging via the suction line of the 

compressor is not allowed. 

A2.5 Adjustment of instruments and safety 

devices 

A2.5.1 Monitron 

Grasso 

For adjustments see table overleaf. 

A2.5.2 Pressure safety switches 

Refer to the table overleaf. Setting procedures are 

described in the Safety Switch supplier instructions. 


QUANTITY OF OIL TO BE FILLED (in dm3) 

Compressor series RC6 Shaft seal housing Oil filters Oil pump Crankcase 

RC46 

11 

RC66 ± 0.5 ± 1.0 ± 0.5 

12 

RC86 13 



Grasso 

Settings of compulsory pressure safeties 

Read-out 

Monitron 1 ) 

Description Min. value Max. value (pre)-Setting 

Psuc Suction pressure 0.3 bar (4.4 psia) NH3 6.2 bar (90 Psia) 5 °C (9 °F) below design 

R22 6.8 bar (99 Psia) evaporating temperature 

R134a 6.2 bar (90 Psia) 

R404A 6.0 bar (87 Psia) 

R507 5.8 bar (84 Psia) 

Pdis Discharge pressure > Psuc 26.0 bar (377 Psia) 5 °C (9 °F) above design 

condensing temperature 

Pdis-Psuc > 0 bar 24.0 bar (348 Psia) < 24.0 bar (348 Psia) 

dPoil Lubrication oil 1.5 bar (22 Psia) 2.5 bar (36 Psia) The oil pressure 

pressure difference 

regulator is adjusted at 

the works, but it may 

occur that this setting 

should be corrected 

during the initial run 

(see A2.5.3) 

1 )In case of Monitron the values are measured via pressure transducers, otherwise protection via switches is compulsory. 

A2.5.3 Re-adjustment of oil pressure regulator (refer 

to fig. A2.1) 

Re-adjustment procedure: 

a) Run the compressor for 15 minutes until the 

crankcase oil is at its stable operating temperature [Toil]. 

b) Determine the oil pressure difference (difference 

between the pressure gauges of the oil and suction 

or [dOil]). 

c) After approx. 15 minutes of operatinf and an oil 

temperature of 50 °C, the oil pressure difference 

should be approx. 2.0-2.5 bar. 

During these first minutes the pressure should be 

slightly higher. 

Fig. A2.1 Oil pressure regulator 


d) Remove the cap nut (3) with alu ring (2), of the oil 

pressure regulator if the pressure needs to be 

re-adjusted. 

e) Turn the slotted pin (1) with a screwdriver clockwise 

or counter clockwise for a higher or lower oil 

pressure respectively, until the required oil pressure 

differences has been achieved. 

f) Replace the cap nut (3) with alu ring (2). 

1 slotted pin 

2 alu ring 

3 cap nut 

4 return from oil separator 

or oil rectifier 

5 oil pressure regulator 



A2.6 Checking direction of rotation of motor shaft 

Prior to installing the intermediate coupling element 

or V-belts, the direction of rotation of the motor 

shaft must be checked either by bumping the 

electrical drive motor or by measuring the rotation 

of the field (direction of rotation normally counter 

clockwise when facing compressor shaft end). 

A2.7 Installing the (drive) guards (if present) 

Only after the compressor is ready for the initial 

startup! Refer to the drive guard installing 

procedures included in the order documentation. 

A2.8 Initial oil warm up 

Prior to the initial start-up (refer to §A2.9), the 

crankcase heater (if present) must be energized. For 

the min. oil temperature (min. [Toil]) refer to page VII. 

A2.9 Initial start-up 

Grasso 

A2.9.1 Limitations of part load operation and 

start-up 

The capacity control serves to adapt the compressor 

capacity at any moment as closely as possible to the 

refrigerating capacity. In order to adapt the capacity, 

a number of cylinders can be put in or out of action 

either individually or collectively. 

Due to start-up limitations and to 

limitations of part load operation it may 

be that not all available part load steps 

are allowed under certain conditions. 

Use of incorrect control steps can 

damage compressor and/or components. 

In the case of a Monitron Controller, all these 

limitations will be checked automatically. 

For a detailed description about these start-up 

and part load limitations refer to the "Engineering 

Data". 

A2.9.2 Pre-start check list 

The following Paragraph covers only the initial 

start of the compressor and not the complete 

refrigeration plant. 


Be sure that all necessary system valves are open 

and that the refrigeration system is ready for start 

up. Use the following check to guarantee that no 

items of importance regarding the compressor 

(package) have been overlooked. 

a) System is charged with refrigerant. 

b) Monitron (if present) is properly installed (refer to 

the Monitron Instruction Manual). 

c) Settings of safety limit switches are adjusted properly. 

d) Direction of rotation of compressor crankshaft is 

correct. 

e) Oil level established in sight glass. 

f) Stop valves to the pressure gauges are open (if 

present). 

g) Suction stop valve is closed (in case the evaporating 

temperature is much higher than the design 

evaporating temperature) and the discharge stop 

valve is open. 

h) Stop valve in the oil return line of the oil separator 

(if present) is closed. 

When all items a) through h) are verified, the 

compressor (package) is ready for the start-up. 

A2.10 Starting and stopping procedures 

When starting the compressor a distinction should 

be made between: 

A2.10.1 Starting for the very first time (between 

brackets [ ] are Monitron units) 

a) Notice §A2.9.2 "Pre-start check list", consult also the 

plant manual and verify the following items: 

- Check the oil temperature [Toil] (refer to the 

"Engineering Data"). 

- Check crankcase oil level (refer to §B4.1). 

b) Start the compressor and check whether the oil 

pressure [Poil] increases. 

Maximum 6 starts per hour and at least 2 

minutes between stopping and starting 

and at least 10 minutes between starting 

and re-starting 



Grasso 

c) Slowly open suction stop valve and watch suction 

pressure [Psuc], which may not exceed the max. 

value as given for each refrigerant in §A2.5.2. 

Refrigerant liquid hammer, will damage 

the compressor; 

Superheat is always necessary! [dTo]≥5 K 

d) More cylinders will be energized. 

Watch maximum allowable motor current 

[Imot] (refer to motor type plate). 

e) Adjust pressure gauge stop valves, in order to avoid 

vibration of the pointers (if present). 

f) Open the stop valve in the oil return line from the 

oil separator (if present). 

Retighten the coupling bolts or check or 

correct the tension of the V-belts and 

retighten the foundation bolts (with 

due respect to the torque settings given 

by the supplier of the fasteners!) after 

50 hours of operation. 

A2.10.2 Restart (not within 2 minutes after a 

stop, respectively starting after a short 

standstill period of time [les than 1 

month]). If Monitron Controlled, refer to 

the Monitron Instruction manual) 

• Proceed to the starting procedure of §A2.10.1 

point a), b) and d). 

A2.10.3 Starting after a seasonal standstill (1 till 

6 months) or maintenance operations 

• Check settings of control and safety equipment 

(refer to §A2.5). 

• Proceed to the complete starting procedure of 

§A2.10.1, items a) through f). 


A2.10.4 Starting after a long standstill period of 

time (more than 6 months) 

Consult your supplier. Monitron "standby" status 

(ready to operate during this long period of time) 

is not allowed! It is recommended to 

proceed with the "Initial start-up" procedure of 

§A2.10.1. 

A2.10.5 Stopping the compressor 

The compressor can be stopped at any moment, 

however, consult the supplier if further actions are 

required. 



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SECTION B: INSPECTION, MAINTENANCE AND TROUBLE SHOOTING ....................................... B1.1 

B1 INSPECTION ................................................................................................................................ B1.1 

B1.1 Periodical inspection ......................................................................................................... B1.1 

B1.2 Survey of periodical inspections ....................................................................................... B1.1 

B2 MAINTENANCE .......................................................................................................................... B1.2 

B2.1 Post start-up maintenance ............................................................................................... B1.2 

B2.2 First maintenance ............................................................................................................. B1.3 

B3 STEPS FOR LONGER SHUT-DOWN PERIODS (more than 6 months) ....................................... B1.4 

B4 LUBRICATION DATA .................................................................................................................. B1.4 

B4.1 Topping up oil with compressor operating .................................................................... B1.4 

B5 EVACUATION OF THE COMPRESSOR ....................................................................................... B1.5 

B6 DRAINING AND CHANGE OF OIL ............................................................................................. B1.5 

B7 CLEANING OF OIL FILTERS ........................................................................................................ B1.5 

B8 CLEANING OF SUCTION GAS FILTER(S) .................................................................................... B1.6 

B9 DISMANTLING, INSPECTION AND RE-ASSEMBLY OF SUCTION AND DISCHARGE VALVES .. B1.6 

B10 COMPRESSOR PURGING ............................................................................................................ B1.7 

B11 TROUBLE SHOOTING TABLE ..................................................................................................... B1.7 

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B.II Installation and Maintenance Manual RC(U)6 v001.99.01.en


B1 INSPECTION 

B1.1 Periodical inspection 

These inspections should be made during the normal 

shut-down periods as much as possible, so the 

compressor is always ready to operate when required. If, 

at that time, the number of running hours slightly differs 

from the scheduled period below, the inspection should 

nevertheless be carried out. 

B1.2 Survey of periodical inspections ("check list") 

CHECK POINTS 1) FREQUENCY REMARKS 

Oil level in crankcase 

Colour of the oil 

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Lubricating oil pressure difference 

[dOil] 

daily 

• 

• 

weekly 

monthly 

• 

B: INSPECTION, MAINTENANCE 

AND TROUBLE SHOOTING 

In this way it will not be necessary to stop the 

compressor at inconvenient times. 

The frequency of inspections is dependent on the type 

of installation and operating conditions. In the case of 

automatically controlled plants, the periodical inspection 

are particularly important. The table below sums up all 

the points on the compressor that have to be inspected 

or maintained along with inspection and maintenance 

frequencies. 

Between 25% and 75% height of the sight glass. For topping up oil, refer to 

§B4.1. 

The oil should be transparently clear. A disappearing white colour points to 

dissolved refrigerant. Refer to § B2.2 for oil analysis frequency. 

The indication of the oil pressure gauge should be 1.5 - 2.5 bar higher than 

the value shown by the suction pressure gauge. 

Oil temperature max. [Toil] • Refer to the "Engineering Data". 

Oil leakage of shaft seal max. • In case of more than 1 cc/hr contact supplier. 

Suction pressure [Psuc] • Check against design conditions. Refer to plant manual. 

Discharge pressure [Pdis] 

• 

Refer to plant manual. For the max. allowable discharge pressure refer to the 

technical data of compressor. 

Suction superheat [dTo] 

Intermediate superheat [dTm] • 

� 5 K 

Discharge temperature max. • 155 °C (311 °F) 

Cooling water temperature (if 

present) min. 

• 

Actual condensing temperature + 10 K. 

Oil temperature min. [Toil] 

• 

During compressor standstill the lower part of the crankcase must remain 

warmer than the surroundings: � 20 °C (NH3) and�30 °C (halocarbons). 

Condition of V-belts 

Check belts for: 

1) Wear (fraying, cuts etc.) and ensure that they do not touch the groove 

• 

bottom. 

2) Tension. Too low a tension gives rise to excessive flapping or oscillation in 

operation. For correct tension consult the instructions given by the V-belt 

supplier. 

Adjustment and operation of 

pressure safety switches 

• 

Refer to §A2.5 and to instructions of switch manufacturer. 

Capacity control 

• 

The time lag between the unloading and loading of one cylinder or cylinder 

group should generally be at least 3 - 5 minutes. 

Switching frequency of the compressor 

• 

The time interval between stopping and starting should be at least 2 minutes 

and between starting and restarting 10 minutes (see §A2.10.2). 

Number of operating hours 

• 

Check the number of operating hours in view of any maintenance operations 

to be carried out. 

Apart from the above check points, the sound produced by the compressor provides an indication or its mechanical condition. If 

abnormal sounds are audible, their cause should be traced and removed immediately in order to prevent serious breakdowns. 

1 ) During the first 50 operating hours the compressor should be checked regularly for all the points mentioned above, at least 

twice every 24 hours and more frequently in cases where irregularities are found. 

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B2 MAINTENANCE (Contractor’s level) 

B2.1 Post start-up maintenance 

After the compressor has run for the initial 100 

operating hours: 

a) Drain the oil and refill the compressor with the 

correct amount of fresh oil. 

b) Exchange or clean the oil discharge filter element. 

c) Exchange or clean oil suction filter element (pos 24 

of fig. 2.1) as given in §B7. 

d) Clean suction gas filter. 

e) Check the compressor shaft seal for leakage. 

If excessive (more than 1 cc/hr) replace the seal. 

f) Check drive 

f1) Retighten the coupling mounting bolts with the 

torque settings as given by the coupling 

manufacturer. 

f2) Verify and if necessary, correct the tension of 

the V-belts as given in the V-belt supplier’s 

instructions. 

g) Verify and if necessary, correct the torque settings 

of all foundation bolts as given in § 7.2 of the 

Compressor Service Instruction Manual. 



B1.2 Installation and Maintenance Manual RC(U)6 v001.99.01.en


B2.2 First maintenance 

The maintenance schedule below indicates after 

how many operating hours maintenance 

operations have to be carried out. This schedule 

can be regarded as a directive, based on the 

experience gained with a large number of 

compressors. 

For most of the maintenance operations the 

compressor must be put out of action. In order to 

avoid that this should take place at inconvenient 

times, the operations should as much as possible 

be affected during a stand-still period. The 

schedule has been drawn up in such a way that 

several operations can be carried out 

sumultaneously, which results in reduced 

maintenance costs. 

Maintenance 

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Number of 

operating 

hours 

Cleaning of oil suction filter and 

renewal of oil discharge filter 

(ref. to par. 9.6). 

100 1 ) 2500 2 ) 

MAINTENANCE SCHEDULE 

5000 

7500 2 ) 

$ $ 

10,000 10,100 12,500 2 ) 

Major inspection to be carried 

out by installation engineer 

15,000 

17,500 2 ) 

$ $ 

Cleaning of suction gas strainer 

(ref. to par. 9.7). $ $ $ $ 

Inspection of suction and discharge 

valves 

(ref. to par. 9.8) 

Draining and change of oil 3) 

(ref. to par. 9.5). 

$ $ 

$ $ $ $ 



20,000 etc. 

1 ) time dependent on pollution. 

2 ) Only for NH3-compressors 

3 ) In the case of a possible rapid pollution of the oil, it should be drained and renewed sooner than at the times given 

v001.99.01.en Installation and Maintenance Manual RC(U)6 B1.3 

Major inspection to be carried 

out by installation engineer


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B3 STEPS FOR LONGER SHUT-DOWN PERIODS 

(> 6 months) 

To shut down a compressor for long term periods, 

proceed as follows: 

a) Tightly shut both the suction and discharge stop 

valves and the stop valve of the oil return line (if 

present). 

b) Disconnect the power source from the compressor 

drive motor and the electrical control cabinet of the 

Monitron CR (if present). 

c) Place a moisture absorbing compound (eg a 

dessicant such as silica gel) inside the control cabinet. 

d) Place warning tags on the electric system and all 

closed stop valves. 

Prior to starting up after a shut down, change the oil 

(refer to §B6) and clean or exchange the oil filters (refer 

to §B7). Determine the starting and stopping 

procedure from §A2.10 prior to start the compressor. 

B4 LUBRICATION DATA 

Determine max Toil and set this value in the safety 

device (Monitron CR, if present). 

Change the oil as soon as an oil analysis (refer to 

§B2.2 for frequency) indicates contaminated oil. 

It is expressly pointed out that it is not 

permitted to mix different types of oil. If 

another type of oil is used, first remove 

all the stale oil in the filters, oil pump, 

crankcase, shaft seal, oil separator and 

oil drains of the installation. 

B4.1 Topping up oil with compressor operating 

Topping up oil is permitted during compressor 

operation. 

Be sure that this oil is the same as in the plant 

(refer to §B4). 



Without affecting the operation of the compressor, 

the oil may be topped up by means of a separate oil 

pump. This pump enables the oil to be forced into the 

crankcase via the oil charging valve, against suction 

pressure. If this oil pump is not available, oil can be 

charged by reducing the crankcase pressure to below 

atmospheric pressure. 

The procedure is as follows: 

a) Connect a hose to the oil charging valve after 

removing the cap nut. 

b) Fill the hose with oil and immerse its loose end in a 

reservoir containing sufficient oil. 

c) Close the suction stop valve so, that the suction 

pressure falls below the atmospheric pressure. 

d) Keep the oil charge valve open as long as the oil in 

the crankcase has attained the required level again. 

Take care that no air is being drawn into the 

crankcase. 

e) Slowly open the suction stop valve to avoid liquid 

hammer which may damage the compressor. 

f) Remove the hose and replace the cap nut with 

gasket onto the oil charging valve. 

Fig. B1 Oil level in compressor sight glass 



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B5 EVACUATION OF THE COMPRESSOR 

To evacuate the refrigeration system refer to §A2.2. 

Procedure to evacuate the compressor: 

a) Close the suction stop valve and the stop valve in 

the oil return line of the oil separator. 

b) Check that the discharge stop valve is open. 

c) Set suction pressure safety switch to 0.3 bar(a). 

d) Start the compressor (manual). 

e) Wait until the compressor will be cut out of 

operation either by the min. suction pressure safety 

switch [min Psuc] or the min. oil differential 

pressure safety switch [dOil]. 

Do not start the compressor again, but close the 

discharge stop valve as soon as possible. 

Be sure the compressor will not start again! 

g) Remove the remainder of the refrigerant, via the 

evacuation/purging valve(s) as prescribed by local 

safety regulations. For the location of these valves 

refer to the "Engineering Data". 

h) Reset the suction pressure safety switch [Psuc]. 

B6 DRAINING AND CHANGE OF OIL 

To top up oil see § B4.1. 

Oil changing procedure: 

a) Evacuate the compressor (refer to §B5). 

b) Drain the oil via the oil charging/drain valve. 

Remove the cover of one or more service openings 

on the compressor side. 

c) Clean the inside of the crankcase with a non-fibrous 

cloth (do not use cotton waste!). 

d) Replace the service cover(s) with a new gasket. 

e) Charge crankcase with clean or fresh oil in 

accordance with the procedure of §A2.3. 



B7 CLEANING OF OIL FILTERS 

In most cases the oil filters have to be cleaned for 

the first time after 100 operating hours. Besides 

thorough cleaning of the strainer element of the 

oil suction filter, the paper filter element of the oil 

discharge filter should be renewed. Also after the 

installation has been extended or modified, the 

filters should be cleaned as if the compressor had 

just been put in operation. The time at which the 

next cleaning has to be carried out highly depends 

on the cleanliness of the installation. 

Small impurities in the refrigerant gas that are not 

retained by the suction strainer eventually find 

their way in the lubricating oil and may cause 

clogging of the oil suction filter. A strong pollution 

of this filter is indicated by a falling oil pressure; in 

this case it is necessary to clean the filter. It is 

recommended, therefore, regularly to check the 

oil pressure during the first 100 operating hours. 

When the filters remain practically clean, cleaning 

can take place simultaneously with the other 

maintenance operations. 

The oil filters can be cleaned as follows: 

a) Drain the oil via the oil charging valve. 

b) Purge the compressor (refer to par. B5) 

c) Remove the discharge filter housing and the 

released paper filter element. Catch up the 

remaining oil present in this housing. After draining 

the oil out of the crankcase, remove one of the side 

covers and remove the gauze filter element by 

unscrewing it from the internal suction pipe. 

d) Clean the gauze filter element of the oil suction 

filter in a receptacle containing oil or a solvent. 

After cleaning, thoroughly dry the element; if 

possible, blow through the filter element with 

compressed air against the normal oil flow direction. 

e) Clean the discharge filter housing and dry it with a 

non-fibrous cloth. 

f) Refit the gauze filter element and place a new filter 

element. 

g) Fit the discharge filter housing against the 

crankcase (do not forget the gasket); also check 

that the filter element is perfectly fit. 

h) Remove the plug on top of the shaft seal housing; 

fill this housing with fresh oil and replace the plug. 

j) Purge the compressor (refer to par. B10) 

k) Check oil level and top up oil as per par. B4.1. 



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B8 CLEANING OF SUCTION GAS FILTER(S) 

a) Evacuate the compressor (refer to §B5). 

b) Remove the four bolts holding the suction stop valve 

and remove the valve. 

c) Pull the strainer element out of the suction strainer 

housing without damaging the gauze. (see also fig. 

RC6-11 on parts list page 12). 

d) Clean element by rinsing it in a solvent. Then 

thoroughly dry the element preferably with 

compressed air. 

e) Check the gauze for damage. 

f) Slide the strainer element again into the housing and fit 

the suction stop valve. Check the oilit gasket for proper 

condition. 

c) Purge the compressor (refer to §B10). 

B9 DISMANTLING, INSPECTION AND RE-ASSEM- 

BLY OF SUCTION AND DISCHARGE VALVES 

The suction and discharge valves of a refrigeration 

compressor are parts that are heavily loaded both 

mechanically and thermally. Wear and life time of the 

valves strongly depend on the operating conditions 

of the compressor. A high working temperature and 

rapid temperature variations shorten the life time of 

the valves, which, for this reason, require regular 

inspection. 

For dismounting, inspection and re-assembly of 

the valves, proceed as follows: 

a) Evacuate the compressor (refer to par. B5). 

b) Remove the cylinder head covers. 

c) Remove the pressure ring and buffer spring. 

d) Lift the complete discharge valve out of the cylinder 

liner. 

e) Remove the suction valve ring and sinusoidal springs, 

which are loose on the collar of the cylinder liner. 

f) Unscrew and disassemble the discharge valve. 

g) Clean all valve parts and check them for break of 

damage. 

MIND! If it appears that valve parts are broken, also 

the cylinder liner and piston of the relevant cylinder 

must be checked for damage. 



The valve rings and valve seats must be undamaged; 

even the slightest damage may easily cause breakage. 

Valve ring and/or seat should be replaced when, due 

to wear, the total score of valve ring and seat is over 

0.2 mm. 

The sinusoidal springs must also be undamaged and 

must have sufficient slack height. 

REMARK! All valve parts can be obtained 

separately, except the discharge valve 

seat, stroke limitor and central bolt. If, 

for example, the discharge valve seat is 

to be renewed, a complete discharge 

valve (including stroke limitor, valve 

ring and sinusoidal springs) should be ordered 

(also refer to the parts list). 

h) Carefully clean all valve parts and slightly oil them with 

compressor oil; then re-assemble the discharge valve. 

j) After reassembling the discharge valve, check 

whether the valve ring and springs can be pressed 

against the stroke limitor, and when released, the 

valve ring is properly pressed back on its seat. 

k) Place the suction valve ring and the corresponding 

sinusoidal springs on the collar of the cylinder liner 

and install the discharge valve, buffer spring and 

pressure ring. 

l) Check the gasket of the cylinder head cover and lay 

the cover onto the cylinder head. 

m) Screw all hexagonal bolts and firmly tighten them. 

n) Purge the compressor (refer to par. B10). 

REMARK! In order to reduce the downtime 

involved in this valve inspection, it 

is recommended to have as many complete 

valve assemblies in stock as there 

are cylinders on the compressor. 

The valves can then be exchanged with 

the valves to be checked. The original 

valves can then be inspected at leisure 

and, if necessary, repaired or replaced. 



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B10 COMPRESSOR PURGING 

Procedure to purge the compressor 

(after maintenance jobs): 

STATUS: 

Stop valves of suction, discharge and oil return line 

are still closed (refer to §B5) and compressor is 

filled with oil (refer to §B6). 

a) Connect a vacuum pump to the evacuation/ 

purging valve(s) and evacuate as prescribed by local 

regulations. For the location of these valves refer to 

the "Engineering Data". 

b) When evacuation is completed open the discharge 

stop valve. 

c) Watch suction and discharge pressure. 

If suction pressure increases quickly, the 

discharge valve assy is leaking. 

d) Start compressor. 

e) Slowly open suction stop valve. 

f) Open the stop valve in the oil return line of the oil 

separator (if present). 

g) If a Self-Limiting Automatic Purger is not installed, 

purge the refrigerating system (refer to the plant 

manual). 

B11 TROUBLESHOOTING TABLE 

The troubleshooting table on the next pages may 

be helpful to quickly trace and remedy failures 

that interfere with the proper operation of the 

compressor. It is emphatically pointed out that the 

cause of a failure must often be sought in the 

refrigeration installation itself. Therefore, it is 

necessary besides this table also to consult the 

plant manual. 

For Monitron CR controlled installations refer also 

to its own trouble shooting table. 





Grasso 

FAULT CAUSE REMEDY 

A Discharge pressure too high 1. Discharge stop valve not fully open 1. Open fully 

2. Discharge pressure gauge defective 2. Renew 

3. Non condensables in system 3. Purge system with 

Grasso Automatic 

Purger 

B Discharge temperature too high 1. Discharge pressure too high 1. See A 

2. Too many cylinders cut out 2. Cut in more cylinders 

3. Suction pressure too low 3. See D 

4. Exessive superheat of suction gas 4. Eliminate exessive 

superheat 

5. Room temperature too high 5. Ventilate engine room 

better 

6. Discharge valve defective 6. Renew 

7. Pressure relief valve leaking 7. Renew 

C Suction pressure too high 1. Capacity control does not operate 1. Repair 

2. Compressor capacity too small 2. Consult installation 

engineer 

3. Suction pressure gauge defective 3. Repair or renew 

4. One or more suction valves defective 4. Repair or renew 

5. One or more discharge valves defective 5. Repair or renew 

6. Pressure relief valve is leaking 6. Renew 

D Suction pressure too low (suction 

pressure safety switch may 

possibly become operative) 

E Crankcase frosted or wet just after 

starting, possibly also during 

operation 



1. Suction stop valve not fully open 1. Open fully 

2. Suction gas strainer polluted 2. Clean 

3. Too little refrigerant in installation 3. Top-up refrigerant 

4. Suction pressure gauge defective 4. Renew 

1. Liquid refrigerant in crankcase due to: In the case of big 

amount of refrigerant: 

stop compressor and 

contact installation 

engineer 

1a. Room temperature too low 1a. See 1a 

1b. Return from oil separator mainly consists 1b. Contact installation 

of liquid refrigerant 

engineer 

1c. Installation operates too wet 1c. Re-adjust installation 

and provide for 

superheat 

1d. Liquid separator too small 1d. Contact installation 

engineer 



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FAULT CAUSE REMEDY 

F Cylinders inactive while compressor 

is operating 

1. Incorrect wiring of capacity control 1. Refer to the "Engineering Data" 

G Too high oil consumption 1. Type of oil not according to oil lubrication oil 

table (too thin oil) 

1. Change oil type 

2. Compressor operates unloaded too frequently 2. Refer to design calculations 

3. No return from oil separator* 3. Check the operation of float 

valve in oil separator 

4. Tube of pressure equalizing obstructed 4. Clean tube 

5. Worn out oil scraper ring(s) 5. Replace ring(s) 

6. Loss of oil due to leakage 6. Repair 

7. Leaking shaft seal (max. 1 cc/hr) 7. Repair shaft seal 

8. Oil level in crankcase too high 8. Refer to §B2 

H Too high oil pressure during 

normal operation at working 

temperature 

1. Lubricating oil pressure regulator not adjusted 

properly or defective 

2. Defective oil pressure and/or suction pressure 

gauge (if present) 

1. Re-adjust or renew 

2. Repair or replace 

J Too low lubricating oil pressure 1. Too little oil in crankcase 1. Top up oil 

2. Disturbed oil circuit: 

Oil suction and/or discharge filter is dirty 



2. Renew the element of oil 

suction filter and/or oil 

discharge filter 

3. Re-adjust or renew 

3. Lubricating oil pressure regulator not adjusted 

properly or defective 

4. Liquid refrigerant in crankcase 4. See E 

5. Defective oil pressure and/or suction pressure 5. Repair or renew 

gauge (if present) 

6. Worn bearings 6. Renew bearings 

*) During the initial start-up, the oil separator (if present) consumes oil before the first oil will be returned. 



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SECTION C: 

Grasso 


Engineerings 

Data Sheet No. 

Description Remarks 

1 Description and operation of capacity control 

2 General data 

3 Limits of operation and fields of applications 

4 Drawings (design details) 

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C.II Installation and Maintenance Manual RC(U)6 v001.99.01.en


3.1 GENERAL 

Grasso 

The capacity control, i.e. the decrease in capacity 

at constant speed and under constant operating 

conditions, takes place stepwise by successively 

cutting out cylinders in pairs. 

This is effected by isolating the discharge space 

direct above the valves for each individual cylinder 

head from the common discharge chamber in the 

compressor housing and by putting it into 

communication with the common suction 

chamber, also located in the compressor housing. 

This socalled “internal recirculation control” is, 

apart from the flow resistance in valves and 

channels, free from losses because the cut out 

cylinders do not compress gas but just circulate it 

under suction pressure. 

3.2 DESCRIPTION OF CAPACITY CONTROL 

As shown in figure 3.1, each controllable cylinder 

head cover is provided with a by-pass slide valve 

(item 9), which can move horizontally forward 

and backward in a guide bush (10) and is 

connected via a push rod (3) to a hot gas 

operated control piston (5) in a horizontal control 

cylinder (4). Slide valve, push rod and control 

piston form one integral steel part. 

Via a three-way solenoid valve (7,8), which is 

mounted outside on top of the cylinder head 

cover against the sealing cover (6) of the control 

cylinder, the space to the left of the control piston 

can be communicated either to suction pressure 

(via lines c and b, the former connected to the 

control cylinder and the latter to the by-pass 

chamber 2) or to discharge pressure (via lines a 

and c, the former connected to the permanent 

discharge chamber 12 in the cylinder head cover). 

Actually, only line a, coming from the top 

connection of the solenoid valve, is an external 

one; the two others b and c are internal bores 

provided in the sealing cover of the control 

cylinder and in the walls of the cylinder head 

cover. These internal bores are not indicated in 

the sections of figure 3.1. 

3.3 OPERATION OF CAPACITY CONTROL 

If the solenoid valve is not energized, line a is 

connected via line c to the control cylinder, so that 

hot gas from the permanent discharge chamber 

enters this cylinder and, as the diameter of the 

control piston is substantially larger than that of 

3. DESCRIPTION AND OPERATION 

OF CAPACITY CONTROL 

the slide valve, the combination piston-rod-valve 

will move to the rightmost position, causing the 

slide valve to shut off entirely the permanent 

discharge chamber from the space direct above 

the discharge valves (11) and the latter to be 

communicated via a ring of circular openings in 

the guide bush with the space between control 

piston and slide valve (by-pass chamber), which is 

in permanent communication with the common 

suction chamber (1) in the compressor housing. 

Both cylinders then operate unloaded as a result 

of the by-pass thus effected. This situation is 

shown in the upper part of figure 3.1. 

When the solenoid valve is being energized, line b 

is connected via line c to the control cylinder, so 

that there is no pressure difference across the 

control piston and the combination 

piston-rod-valve is kept in its leftmost position by 

the pressure prevailing in the permanent 

discharge chamber and exerted onto the 

righthand face of the slide valve. The space direct 

above the discharge valves then communicates, 

via the afore mentioned circular openings in the 

guide bush of the slide valve, with the permanent 

discharge chamber, so that both cylinders operate 

normally. This situation is shown in the lower part 

of figure 3.1. 

For the standard capacity control part-load steps of 

the various compressor types and the corresponding 

energizing sequence of the solenoid valves, refer to 

the figures 3.2, 3.4 and 3.5 for compressor types 

RC6 and to figures 3.6, 3.8 and 3.9 for compressor 

type RC6W. 

3.4 PARTIALLY UNLOADED STARTING 

In order to be sure that all controllable cylinder 

pairs always operate fully unloaded when there is 

no pressure difference between discharge and 

suction, a spring is mounted between each sealing 

cover and control piston to ensure that in that 

case all control pistons and slide valves are kept in 

their rightmost position, regardless of whether the 

corresponding solenoid valves are energized or 

not. 

On the other hand, to create sufficient discharge 

pressure to operate all available capacity control 

slide valves when starting the compressor at zero 

pressure difference between discharge and 

suction, one cylinder head cover of each 

compressor type is non-controllable, i.e. it has no 

built-in slide valve and control piston, but is 

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provided instead with only a simple vertical 

partition to keep the common suction and 

discharge chambers in the compressor housing 

apart from each other. 

Consequently, when the discharge pressure is 

higher than the suction pressure, only partially 

unloaded starting is possible. 

Therefore, it is recommended to always check the 

electric drive motor in this respect, depending on 

compressor design speed and starting conditions, 

the procedure of which is set out in paragraph 4.7. 

3.5 ALTERNATIVES TO CAPACITY CONTROL 

The four-cylinder compressor types RC46 can also be 

delivered with an alternative capacity control, 

including three part-load steps (25, 50 and 75%) 

instead of only one (50%) in the standard version. 

For the switch sequence of cylinders and solenoid 

valves of this alternative capacity control, refer to 

figure 3.3 and figure 3.7 for compressor types 

RC46 and RC46W respectively. 

These additional steps are obtained by replacing 

the non-controllable cylinder head cover of 

cylinders nr. 1 and 3 (RC46 in fig. 3.3) or cylinders 

nr. 2 and 4 (RC46W in fig. 3.7) by a partly 

controllable one of special design, which means 

that it has a partition in the middle of the space 

direct above the discharge valves to separate the 

two adjacent cylinders entirely from each other, 

thereby causing the built-in control piston and 

slide valve to be effective for cylinder nr. 1 (RC46) 

or cylinder nr. 2 (RC46W) only and the discharge 

valve of cylinder nr. 3 (RC46) or cylinder nr. 4 

(RC46W) to be always in communication with the 

permanent discharge chamber in the cylinder head 

cover and the common discharge chamber in the 

compressor housing. 

So, only this one cylinder nr. 3 (RC46) or cylinder nr. 

4 (RC46W) is always in operation, which has the 

extra advantage of also reducing the starting load 

from 50 to 25%. 

On special order, just by adding the symbol Z after 

the type designation, each standard compressor 

type can also be delivered without any capacity 

control. In that case not only one but all cylinder 

head covers are of the non-controllable type, i.e. not 

provided with built-in control piston and by-pass 

slide valve. 

However, the consequence of such a (cheaper) 

choice is that either fully loaded compressor 



starting has to be accepted, inevitably resulting in 

a more powerful electric motor to be installed, or 

special provisions are to be made by the installer 

in the field to overcome this inconvenience, for 

instance by applying an external line with solenoid 

valve (only open, so energized only during 

starting) between the suction and discharge line 

of the installation, combined with a non-return 

valve in the same discharge line. 

Important installation requirement! 

To prevent, during prolonged compressor 

stand-still, a gradual pressure equalisation 

between condenser and evaporator due to 

slow leakage of refrigerant gas via the 

slide valve, a non-return valve should all 

the times be mounted in the external 

discharge line. 

page C1.2 Installation and Maintenance Manual RC(U)6 v001.99.01.en


a 

7 

a 

7 

b b 

c 

6 

5 

4 

3 

2 

1 

b b 

c 

6 

5 

4 

3 

2 

1 

Grasso 

1. common suction chamber 

2. by-pass chamber 

3. push rod 

4. control cylinder 

5. control piston 

c 

c 

➙ ➙ 

8 

8 

9 10 

9 10 

a 

a 

➙ ➙ 

11 12 

11 12 

6. sealing cover 

7. three-way solenoid valve with LED indication 

(schematic indication) 

8. three-way solenoid valve (actual location) Grasso 

code 06.80.111, suitable for 200-240V and 50/60Hz 

Fig. 3.1 Principle of capacity control 



solenoid valve not energized 

CYLINDERS OUT OF OPERATION 

solenoid valve energized 

CYLINDERS IN OPERATION 

➙ 

➙ 

➙ 

13 

13 

9. (by-pass) slide valve 

10. guide bush 

11. space direct above discharge valves 

12. permanent discharge chamber 

13. common discharge chamber 



Grasso 

4 

4 

A 

2 

A 

2 

Number of solenoid valves: 1 (A,) 

Number of control steps: 2 

B 

1 

1 

3 

Fig. 3.2 Standard capacity control of compressor RC46 

Number of solenoid valves: 2 (A,B) 


3 

Fig. 3.3 Alternative capacity control of compressor RC46 



solenoid valves energized 

- A � 

� 

Electrical 

control 

50 100 % Capacity 

No. of operating cylinders 

1 1 

- 2 

3 3 

- 4 


- - A A � 

- B - B 

� 


(standard) 

Electrical 

control 

25* 50 75* 100 % Capacity 


- 1 - 1 

- - 2 2 

3 3 3 3 

- - 4 4 

* Optional (see paragraph 3.5) 


(alternative) 



8 

6 

A 

4 

Grasso 

3 

A 



Number of solenoid valves: 3 (A,B,C) 


7 

B 

3 

5 

2 

B 

2 

C 

6 

1 

4 


1 

5 





- - A � 

- B B 

� 

Electrical 

control 

33.3 66.6 100 % Capacity 


1 1 1 

- 2 2 

- - 3 

4 4 4 

- 5 5 

- - 6 


- - - A � 

- B B B 

- - C C 

� 

� 


Electrical 

control 

25 50 75 100 % Capacity 


1 1 1 1 

- - 2 2 

- 3 3 3 

- - - 4 

5 5 5 5 

- - 6 6 

- 7 7 7 

- - - 8 

v001.99.01.en Installation and Maintenance Manual RC(U)6 page C1.5 

RC86


Grasso 

2 

4 

4 


B 

2 

Number of solenoid valves: 1 (A) 



A 

A 

1 

1 

3 

Fig. 3.6 Standard capacity control of compressor RC46W 

3 


Fig. 3.7 Alternative capacity control of compressor RC46W 




- A 

- B - B � 

- - A A 

� 

Electrical 

control 

25 50 75 100 % Capacity 


- - 1 1 

- 2 - 2 

- - 3 3 

4 4 4 4 

� 

� 

Electrical 

control 

50 100 % Capacity 


- 1 

2 2 

- 3 

4 4 

RC46W 

(standard) 


(alternative) 



4 

8 

3 

6 

Grasso 



5 

B 



Number of solenoid valves: 3 (A,B,C) 

2 


7 

C 

3 

2 

B 

6 

A 

1 

A 

4 

1 

5 

- - B � 

- A A 

� 

Electrical 

control 

33.3 66.6 100 % Capacity 


- - 1 

- 2 2 

3 3 3 

- - 4 

- 5 5 

6 6 6 


- - - C 

- B B B 

- - A A 




� 

� 

� 


Electrical 

control 

25 50 75 100 % Capacity 


- - - 1 

- 2 2 2 

- - 3 3 

4 4 4 4 

- - - 5 

- 6 6 6 

- - 7 7 

8 8 8 8 




Grasso 





4.1 TECHNICAL DATA 

Table 4.1 Technical data 

COMPRESSOR TYPE RCF46/RCA46 RCF66/RCA66 RCF86/RCA86 

Number of cylinders z 4 6 8 

Cylinder arrangement 2 x V 2 x W 2 x VV 

Cylinder bore D mm 85 

Piston stroke S mm 66 

Direction of rotation both directions permitted 

Swept volume at full-load and n = 1450/min Vs m 3 /h 130.3 195.5 260.7 

Standard compressor speeds (with V-belt drive) 

motor speed 1450/min (50 Hz) 

n min -1 

810 - 855 - 905 - 1015 - 1140 - 1215 - 1285 - 1450 

motor speed 1750/min (60 Hz) 800 - 875 - 980 - 1030 - 1095 - 1225 - 1380 - 1465 

Standard steps of capacity control (expressed in 

percentage of full-load swept volume) 

1 ) % 100 - 50 100 - 67 - 33 100 - 75 - 50 - 25 

Main dimensions, connections and required free space Refer to par. 4.2. 

Mass of bare compressor (without 

flywheel and other accessories) 

Oil charge in crankcase (centre line of sight glass) 

2 ) dm 3 

kg 280 345 400 

9.2 (8.5) 10.0 (9.3) 10.8 (10.1) 

Oil type to be used Refer to par. 4.3. 

Starting torque Refer to par. 4.7. 

Friction power at n = 1450/min and 55 o C oil temperature 3 ) Pw kW 1.10 1.53 2.22 

Mass moment of inertia of crank mechanism 

(without flywheel) 

Centre of gravity and free forces and moments 

Torsional elastic substitute systems of crankshaft 

4 ) Id kg.m 2 

0.0361 0.0421 0.0478 

5 ) Refer to par. 4.4. 

6 ) Refer to par. 4.5. 

Sound rating Refer to par. 4.8. 

1 ) See also Chapter 3. 

Grasso 

2 

) The figures between brackets indicate the smaller oil charge for the 

RCA6W compressors due to the presence of an oil cooler. 

3 

) Pw is needed for calculating the condenser capacity Qc. 

See also paragraph 4.6. 

Pw = (n/1000).(0.02293.z 2 - 0.08207.z + 0.71931). 

4. GENERAL DATA 

4 ) The mass moment of inertia Id, expressed in SI-units, is required to 

determine the so-called coefficient of speed fluctuation. 

5 

) The centre of gravity and free forces and moments are of 

importance when calculating a vibration-free mounting of the 

compressor. 

6 

) These crankshaft substitute systems are required to carry out 

torsional vibration calculations in case the compressor is driven by 

an internal combustion engine. 



Grasso 

4.2 MAIN DIMENSIONS AND SPACE REQUIREMENTS (for connections see table 4.2 ) All dimensions in mm. 

Fig. 4.1a Dimensioned sketch of compressor RC46 

Fig. 4.1b Dimensioned sketch of compressor RC46W 


For unobstructed removal of the crankcase inspection side covers, 

a block of at least 40 mm height should be placed under each foot 

when installing the compressor on a foundation or base frame. 






Grasso 












Grasso 












Grasso 

Table 4.2 Connections of RC6 and RC6W-compressors 

COMPRESSOR TYPE RC46(W) RC66(W) RC86(W) 

MAIN CONNECTIONS * outer pipe diameter of welding neck in flange 

suction 1 DN40 DN50 DN50 

discharge 

AUXILIARY CONNECTIONS 

2 DN32 DN40 DN50 

suction pressure 3 

1 

/4“ BSP 

discharge pressure 4 

1 

/4“ BSP 

oil pressure 

crankcase pressure 

5 

6 

1 

/8“ BSP 

1 

/4“ BSP 

Remark: 

return from oil separator or 

oil rectifier 

7 

1 

/4“ BSP 

connections 3, 4, 5, 6, 7, 9 and 10 are plugged off. 

oil charge and drain valve 8 

1 

/4“ BSP 

oil temperature 9 

1 

/4“ BSP 

crankcase heating 10 1 /2“ BSP female to suit thread of heating element 

oil leakage drain of rotary shaft seal 11 clamp coupling provided with Ø6 x 1 mm steel precision tube 

water inlet/outlet (RCA6W only) 12 Ø19 mm hose connector 

* Provided with a purging and evacuation stop valve type TAH8 (standard on discharge connection and optional on suction connection). 

Fig. 4.4 Dimensions of shaft end 




4.3 LUBRICATING OILS (choice and recommendations) 

For lubrication of refrigeration compressors, several 

brands and types of specially developed lubricating oils 

are on the market. The choice of oil depends not only 

on its good lubrication properties (viscosity) and 

chemical stability at the operating conditions of the 

compressor, but also on the operating conditions of the 

refrigerating plant (solidifying and floc point, solubility). 

Grasso has tested and approved for use in its 

reciprocating-compressors the brands and types of oil 

as listed in the adjacent table 4.4. 

The choice of the viscosity of the lubricating oil 

depends on the operating conditions of the 

compressor. The oil viscosity should always be more 

than 15 cSt (based on bearing construction 

requirements of the compressor). For the selection of 

the oil viscosity grade number, refer to table 4.3 below. 

A higher viscosity should be chosen, when a high oil 

temperature is expected, due to arduous operating 

condition such as: 

• high evaporating temperature; 

• large superheat of the refrigerant suction vapour; 

• prolonged part-load operation with a large number 

of cylinders cut-out; 

• a high surrounding temperature; 

• large pressure ratio. 

Remark 

For the oil types mentioned in the table 4.4, applied 

with the refrigerants R22, NH3 and R134a, the 

minimum requirement of the actual oil viscosity of 

15 cSt is fulfilled, but only when the maximum oil 

temperature as mentioned in the table 4.3 below is 

not exceeded. 

Refrigerant 

used 

Max. 

allowable 

evaporating 

temperature 

to,max. ( o C) 

Grasso 

Table 4.3 Oil selection table 

Maximum allowable 

crankcase oil temperature* 

ISO VG-number 

46 68 100 

NH3 - 60 68 76 

-64 59 68 76 

-30 56 66 74 

R22 

-20 

-10 

54 

51 

64 

62 

71 

68 

0 44 56 64 

+10 29 47 56 

-50 - 74 83 

-30 - 71 80 

R134a 

-20 

-10 

- 

- 

69 

67 

79 

77 

0 - 61 74 

+10 - 47 67 

* Data based on minimum oil viscosity of 15 cSt at the bearing 

surfaces, which is derived from the oil type, solubility of the 

refrigerant in the oil (halocarbon refrigerants only) and operating 

conditions. Assumed is that the oil temperature at the bearing 

surfaces = 6 K above crankcase oil temperature. 

The grey areas show the recommended ISO VG-numbered oils. 

Example: R22, to,max. = 0 o C : recommended oil type is ISO VG100 

NH3 under normal operating conditions, oil type with 

ISO VG68 is recommended. 

Refrigerant 

used 

NH3 

and 

R22 

Brand Type designation 

ISO VG 

number 1 ) 

AVIA Avilub FC 46/68 

2 

) 

BP 

Energol LPT-F 46 

Energol LPT-F 68 

46 

68 

CASTROL Icematic 299 

2 

) 

CPI CP-1009-68 

2 

) (NH3 only!) 

ELF Elfrima FR 68 

2 

) 

Zerice 46 

46 

ESSO 

Zerice 68 

Zerice S 46 

68 

46 

Zerice S 68 

68 

FINA Purfrigol MP 68 68 

FUCHS 

KC 46 

KC 68 

46 

68 

KROON OIL Carsinus FC 46/68 

2 

) 

MOBIL Arctic oil 300 

2 

) 

PETRO 

CANADA 

Reflo 68A 

2 

) (NH3 only!) 

Q 8 

Stravinsky B 

Stravinsky C 

2 

) 

2 

) 

SHELL 

SUN-OIL 


Table 4.4 Approved oil types for Grasso reciprocating 

compressors 

Clavus 46 

Clavus 68 

Clavus G 46 

Clavus G 68 

Clavus G 100 

Suniso 3.5 GS 

Suniso 4 GS 

Suniso 5 GS 

Suniso 4 SA 

46 

68 

46 

68 

100 

2 ) 

2 ) 

2 ) 

2 ) (NH3 only!) 

TEXACO Capella WF 68 68 

2 

TOTAL Lunaria S 46/68 

) 

R134a 

and 

R404A 3 CASTROL 

Icematic SW 68 

68 

Icematic SW 100 100 

2 

CPI 

Solest 68 

) 

2 

Solest 120 

) 

2 

Triton SE 55 

) 

2 

DEA Triton SE 80 

) 

2 

Triton SE 120 

) 

2 

ELF 

Planetelf ACD 68 

) 

2 

Planetelf ACD 100 ) 

2 

FINA 

Purfrigol ST VG 68 ) 

2 

Purfrigol ST VG 100 ) 

FUCHS 

Reniso E 68 

68 

) 

Reniso E 100 

100 

2 

ICI 

Emkarte RL 68S 

) 

2 

Emkarte RL 100S 

) 

2 

MOBIL 

EAL Arctic 68 

) 

2 

EAL Arctic 100 

) 

2 

SHELL 

Clavus R68 

) 

2 

Clavus R100 

) 

2 

SUN-OIL Suniso Excel 

) 

TEXACO 

Capella HFC 68 

68 

Capella HFC 100 100 

Some of the oil types listed in the table may be marketed under other 

names and/or designations; these oils can also be used, provided 

their identity can be proved beyond any doubt. Application of other 

oils is not permitted without written consent of Grasso. 

1 

) Viscosity grade number designation according to ISO Standard 

3448. 

2 

) Consult your oil supplier to determine the maximum allowable oil 

temperature at an oil viscosity of 15 cSt, under prevailing operating 

conditions and refrigerant used. 

3 

) In case of R404A always consult your oil supplier in advance for 

advise. 



5.1 INDIVIDUAL LIMITS OF OPERATION 

With an operating compressor several working 

conditions arise which one by one are bound to certain 

limits. These so-called “individual operation limits” are 

determined by structural limitations of the compressor 

itself or they are based on thermodynamic and 

practical considerations. They apply to both single-stage 

and booster compressors. 

When operating the compressor, none of the limits of 

operation as stated in the table 5.1 below must be 

exceeded. 

Table 5.1 

Note: 

In practice it is not so much the individual limits 

of operation, described in this paragraph, as 

combinations of them that are decisive for the 

conditions under which a compressor may 

operate. To check the various possibilities in this 

respect, use should be made of the “fields of 

application” according to the figures 5.1 to 5.5. 

REFRIGERANT NH3 R22 R134a R404A 

Compressor speed n min -1 min. 800 

max. 1500 

Suction pressure 

= evaporating pressure 

= crankcase pressure 

Evaporating temperature 

= saturation temperature 

at suction pressure 

Actual suction temperature 

1 ) po bar(a)* 

1 ) to 

2 ) ta 

o C 

min. 0.3 

max. 6.2 6.8 6.2 6.0 

min. -55.1 -63.8 -50 -68.1 

max. +10.2 +10.0 +22.6 -0.1 

o C min. -50 

Suction superheat ∆to K min. 5 

Discharge pressure = condensing pressure 

3 

) pc bar(a)* max. 26 

Condensing temperature 

= saturation temperature at discharge pressure 

Discharge temperature 

Pressure ratio (pc/po) 

Pressure difference (pc-po) 

Grasso 

Oil temperature in crankcase 

* 1 bar = 10 5 N/m 2 = 100 kPa = 1.02 kgf/cm 2 = 14.5 psi. 

tc 

4 ) te 

o C max. +59.8 +63.2 +79.5 +55.6 

o C max. +155 

5 

) j - 

min. 1.5 

max. 10 15 

6 

) ∆p bar* max. 24 

7 ) toil 

1 

) The minimum values of po and to are only of importance for 

booster applications. In that case the maximum value of to also 

applies to the saturation intermediate temperature (tm). 

For halocarbon refrigerants the maximum values of po and to are 

based on a density of the suction gas of 30 kg/m 3 . 

During start-up and immediately thereafter, po,max. may be 

exceeded slightly [up to 11 bar(a) max.] and temporarily, but no 

longer than about 5 minutes. 

The maximum static crankcase pressure during compressor 

standstill is 21.5 bar(a). 

2 

) Only of importance for booster application. 

3 

) This pressure is also the maximum allowable pre-set value of the HP 

safety switch. 

4 

) This is the actual discharge temperature, measured directly in the 

gas flow inside the cylinder head covers, just above the discharge 

valves. 

o C 

5. LIMITS OF OPERATION AND 

FIELDS OF APPLICATIONS 

min. +20 +30 

max. refer to pragraph 4.3 

5 

) Pressure ratio limits are not absolute but arbitrary values based on 

practical considerations. 

6 

) The standard built-in overflow safety valve between suction and 

discharge chamber in the compressor housing has been factory-set 

to 24.5 (+10%) bar to prevent advanced opening during normal 

operation at ∆p ≤ 24 bar. 

7 ) Indicated minimum value is the lowest oil temperature at which 

compressors are allowed to be started. 

The maximum oil temperature depends on the operating 

conditions of the compressor, the oil type used and (for halocarbon 

refrigerants only) the solvability of the refrigerant in the oil. A 

minimum actual oil viscosity of 15 cSt is always required. 

When using ammonia as refrigerant, the maximum oil temperature 

will be exceeded only when a combination occurs of high ambient 

temperature, high suction superheat and part-load operation. In 

that case an oil cooler is required. A water-cooled oil cooler always 

form part of the standard delivery of a RC6W-compressor. 



Grasso 

5.2 FIELDS OF APPLICATION FOR SINGLE-STAGE 

AND BOOSTER OPERATION. 

The following 5 diagrams, related to the refrigerants 

R134a, R22, R404A and NH3 represent the fields of 

application at continuous operation with different 

conditions at any speed between 800 and 

1500/min. In case of RC6 and booster application 

the compressor manufactuer should be consulted. In 

each diagram the area comprising all allowable 

combinations of evaporating temperature to and 

condensing temperature tc (general field of 

application) is enclosed by a broken bold line, of 

which each line section corresponds to one of the 

individual operation limits as stated in table 5.1. 

Symbols used in diagrams: 

to = evaporating temperature 

po = evaporating pressure 

tc = condensing temperature 

pc = condensing pressure 

j = pressure ratio = (pc/po) 

∆p = pressure difference = (pc-po) 

∆to = suction superheat 

te = discharge temperature in cylinder head covers 

Vs = part-load swept volume (= part-load capacity) 

expressed in percentage of full-load (100%) 

Fig. 5.1 Field of application for RC6 with refrigerant R134a 



Fig. 5.2 Field of application for RC6 with refrigerant R22 

Fig. 5.3 Field of application for RC6 with refrigerant R404A 



Grasso 

5.3 LIMITATIONS OF PART-LOAD OPERATION 

Fig. 5.4 Field of application for compressor type RC6 with NH3 

Fig. 5.5 Field of application for compressor type RC6W with NH3 

If a RC46 or RC86 is to be operated continuously 

at the minimum part-load step of 25%, the 

manufacturer should be consulted first to check 

whether this is allowed under the expected design 

conditions. 

In case of a RC6-compressor operating 

continuously at part-load, the general field of 

application is reduced in the sense that for each 

step of capacity reduction the limit line for te = 

155 o C moves to the right as shown in fig. 5.4, by 

four Vs-indications in percentage. 



In case of a RC6W-compressor, however, there are 

no part-load restrictions. In other words, the 

general field of application as shown in fig. 5.5, 

also remains valid for part-load operation down to 

and including the standard minimum capacity 

control step of Vs = 25%. 



Grasso 





1 

2 

3 

4 

5 

Grasso 

31 

�� 

�� 

�� 

�� 

Fig. 2.1 Construction of standard bare compressor (RC66W) 

DESIGN DETAILS OF STANDARD 

BARE COMPRESSOR 

30 

33 

6 

7 

32 

8 

9 

10 

11 

12 

1. cylinder head cover 

(water-cooled) 

2. lifting eye 

3. suction connection 

4. oil differential pressure 

safety switch (optional) 

5. crankcase heater (optional) 

6. suction and discharge 

valve assembly 

7. cylinder liner 

8. piston and connecting rod 

9. discharge connection 

10. oil return check valve 

11. sight glass 

12. inspection side cover 

13. 3-way solenoid valve 

14. by-pass slide valve 

15. suction chamber 

16. tube for pressure equalizing 

17. rotary shaft seal 

18. crankshaft 

19. shaft seal housing 

20. oil leakage drain 

21. oil suction filter 

22. crankcase 

23. discharge chamber 

24. oil discharge filter 

25. oil filter housing 

26. oil pump 

27. bearing cover 

28. oil charge and drain valve 

29. oil cooler (water-cooled) 

30. cooling water hose 

31. water inlet connection 

32. water outlet connection 

‘ 33. cast-in channel 

for cooling water 

34. Plug cooling water channel 



1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

7 

8 

9 

10 

Grasso 

11 

12 

� 

DISCHARGE 

1 2 

➙ 

12 13 

➙ 

➙ 

Fig. 2.2 Rotary shaft seal 

� 

SUCTION 

Fig. 2.3 Suction and discharge valve assembly 

3 

4 

5 

6 



14 

1. shaft seal housing 

2. O-ring 

3. counter-slip ring 

4. slip ring 

5. flexible elastomer bellows 

6. spring 

7. spring holder 

8. driving band 

9. supporting ring 

10. retainer shell 


12. main bearing bush 

13. crankcase 

14. oil supply from internal 

lubricating circuit in crankcase 

1. central bolt 

2. discharge valve stroke limitor 

3. pressure ring 

4. sinusoidal buffer spring 

5. discharge valve seat, also 

suction stroke limitor 

6. cylinder liner, also suction 

valve seat 

7. O-ring 

8. suction valve ring with two (RCF6) or 

one (RCA6) sinusoidal spring(s) 

9. discharge valve ring with two (RCF6) 

or one (RCA6) sinusoidal spring(s) 

10. O-ring in crankcase partition 

11. head plate 

12. crankcase partition 



➊ 

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1. crankcase 

2. suction welding 

neck flange 

Grasso 

➌ 

➍ 


4. strainer element 

Fig. 2.4 Suction gas strainer 

➋ ➊ 

�� 

�� 

�� 

�� 

�� 

�� 

Fig. 2.6 Lubrication system 



➌ ➍ ➎ 

1. crankcase 

2. discharge welding 

neck flange 

Fig. 2.5 Pressure relief valve 

➋ 


4. discharge chamber 

5. overflow safety valve 

1. oil discharge filter 

2. oil pump 

3. oil suction strainer 

4. connections for external 

oil return line with 

lubricating oil pressure 

regulator and for (optional) 

oil pressure safety switch 




Grasso 





Grasso 



SECTION D: STANDARD ILLUSTRATED PARTS LIST ..................................................................... 

D1 Spare parts list RC6 .................................................................................................................... C1 - C16 

....................................................................................................................................... A1 - A8 

v001.99.01.en Installation and Maintenance Manual RC(U)6 D.I


Grasso 


D.II Installation and Maintenance Manual RC(U)6 v001.99.01.en


Grasso 

The illustrated parts list on the following pages is meant for identification and accurate specification of 

spare parts. In order to facilitate quick retrieval of the required parts, the list and corresponding figures 

is divided into the following groups of parts: 

GROUP OF PARTS PARTS LIST 

Page: 

Figures 

All parts shown in the figures bear an item number. 

Assemblies are indicated by a dotted frame with 

separate item number around the parts included in 

that particular assembly; 

the parts themselves bear the same item number, 

followed by a sequence number (e.g. 2.1, 2.3, 2.3, etc.). 

Parts lists 

The parts are specified by the headings “Item”, 

“Description” “Ref. no.” and “Qty” (= Quantity). 

* If an asterisk is used instead of the Ref. no., this means 

that the relevant part cannot be obtained separa- 

STANDARD ILLUSTRATED PARTS LIST RC6 

CORRESPONDING FIGURE 

No.: 

• Compressor housing with connections 2 RC6-1 

• Main bearings 2 RC6-2 

• Crankshaft 5 RC6-3 

• Piston and connecting rod 5 RC6-4 

• Suction and discharge valve 6 RC6-5 

• Rotary shaft seal 9 RC6-6 

• Oil pump 9 RC6-7 

• Capacity control mechanism 10 RC6-8 

• Oil discharge filter 10 RC6-9 

• Flanged main connections 13 RC6-10 

• Suction gas strainer 13 RC6-11 

• Oil suction filter 14 RC6-12 

• Oil differential pressure safety switch 14 RC6-13 

• Oil pressure regulator 14 RC6-14 

• Standard sets of parts and seals 16 --------- 

tely. 

When for some part no quantity has been given, the 

quantity required depends on the compressor size. 

When determining the required quantity of parts, it 

should be considered that the listed quantities relate 

to the corresponding figure and not to the compressor 

as a whole. When ordering, for example, valve 

rings for two discharge valves, the quantities stated 

in the relevant list must be doubled, because these 

apply to one discharge valve only. 


This is a RC6 compressor, including water cooled cylinder 

heads 

How to order! 

It is emphatically pointed out that a prompt despatch of the correct spare parts can be 

guaranteed only if the following information is given: 

1. Type designation of the compressor 

shown on the compressor name plate 

2. Serial number of the compressor 

3. Quantity, Description and Ref. No. of the required parts. 

0089238-v004.00.02.en RC6 C1


Item Description Ref. No. Qty Remarks 

COMPRESSOR HOUSING WITH CONNECTIONS FIG. RC6-1 

1 Cylinder head cover assy 

* — with capacity control 

1.1A Cylinder head cover RC6-2CR 

23.36.521 — with cap. control for 2 cyl. 

Cylinder head cover RC6-2CR 

23.36.525 — RC6W: with cap. control for 2 cyl. 

1.1B Cylinder head cover RC6-1CR 

23.36.510 — with cap. control for 1 cyl. 


23.36.515 — RC6W: with cap. control for 1 cyl. 

1.2 Hex. head bolt M10x120 

01.10.512 2 

1.3A Oilit gasket 190x405x1.5-2CR 

09.07.192 — on item 1.1A 

1.3B Oilit gasket 190x405x1.5-1CR 

09.07.191 — on item 1.1B 

2 

2.1 

2.2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

Cylinder head cover assy 



Oilit gasket 190x405x1.5-0CR 

Hex. head bolt M10x100 


Washer M10 

Crankcase 

Oilit gasket 175x290x1.5 

Inspection side cover 175x290 

Inspection side cover 175x290WK 


O-ring 2.62x32.99 

Sight glass 2.9x60 


Eye bolt M16 

Safety relief valve 26 5G33 

Plug G13S 

Crankcase heating element 

Stop valve TAH8-12 

Oil return orifice 

Alu sealing ring 21x25x1 

Plug G21 

Plug G21 


Alu sealing ring 13,5x20x1 

Nipple coupling 12G13 


* 

23.36.500 

23.36.505 

09.07.190 

01.10.510 

01.10.512 

11.13.501 

* 

09.07.175 

05.30.175 

05.30.178 

01.10.540 

09.52.284 

12.24.029 

01.10.316 

01.18.812 

12.49.333 

01.36.134 

13.72.203 

06.07.011 

01.23.139 

09.12.021 

01.36.216 

01.36.216 

09.14.023 

09.12.014 

03.38.131 

03.38.211 

— 

— 

— 

20 

20 

36 

1 

1 

2 

2 

16 

1 

1 

3 

2 

1 

5 

1 

1 

2 

2 

3 

1 

1 

5 

1 

1 

without capacity control 

on type RC6W only 

18 on item 1 (for RC6 types only) 

18 on item 1 (for RC6W types only) 

RC6 (2x), RC6W (1x) 

RC6W (1x) 

if connection not in use 

in RC46(W) compressor only 

in types RC66(W) & RC86(W) 

MAIN BEARINGS FIG. RC6-2 

1 

2 

2.1 

2.2 

2.3 

2.4 

3 

4 

5 

Grasso 

Flange bearing 60x15x11.5 

Bearing assy 

Pump housing RC6 

O-ring 3.53x209.14 

Flange bearing 60x50xM10 

Socket head screw M10x100 

Washer M10 



11.43.600 

* 

––––- 

09.52.365 

11.43.651 

01.04.510 

11.13.501 

01.10.540 

01.10.535 


1 

1 

1 

1 

1 

4 

16 

8 

8 

driving end 

refer to page 9 

oil pump end from 95.08.1648 

C2 RC6 0089238-v004.00.02.en


1 

3 

5 

Grasso 

2 

2.3 

2.2 


2.1 

2.4 

4 

3 

RC6-1 




Grasso 







CRANKSHAFT FIG. RC6-3 

1A 

1B 

1C 

1.1 

2 

3 

4 

Crankshaft E-RC6 

Crankshaft K-RC6 (with approval) 





Crankshaft E/K-RC6 

Key 14x9x70 

Carrier disc 60x5 

Socket head screw M10x25 

22.36.400 

22.36.410 

22.36.600 

22.36.610 

22.36.800 

22.36.810 

* 

11.02.570 

11.25.106 

01.04.525 

1 

1 

1 

1 

1 

1 

1 

1 

1 

2 

4-cylinder compressor 



from 95.08.1648 

PISTON AND CONNECTING ROD FIG. RC6-4 

1 

1.1 

1.2 

1.3 

1.4 

2 

2.1 

2.2 

2.3 

2.4 

Grasso 

Piston assy 85RC6 

Piston 85RC6H 

Gudgeon pin 26x18x69RC6 

Safety ring 

Set of piston rings 85RC6 

Connecting rod assy 60x170xRC6 

Con rod 170RC6 

Con rod bolt MF8x1 

Locking plate M8 

Hex. nut MF8x1 

24.36.010 

* 

24.36.260 

* 

09.74.084 

24.36.500 

* 

01.11.401 

11.39.400 

01.47.405 


0089238-v004.00.02.en RC6 C5 

1 

1 

1 

2 

1 

1 

1 

2 

2 

2



SUCTION AND DISCHARGE VALVE FIG. RC6-5 

1 

2 

3 

4 

5 

5.1 

5.2 

5.3 

5.4 

5.5 

5.6 

5.7 

6 

7 

8 

9 

10 

11 

12L 

12H 

13 

Grasso 


Washer M10 

Pressure ring RC6 

Sinusoidal buffer spring 87x124x4 

Discharge valve assy RC6 

Locking nut M8 

Washer M8 

Discharge valve stroke limitor 

Sinusoidal spring 64x76x0.5 

Discharge valve ring 64x76x1 

Suction stroke limitor 

Fitted bolt M8x40 

Damper ring 108x87x4 

Sinusoidal spring 88x108x0.7 

Suction valve ring 88x108x0.7 

O-ring 3.53x117.07 

Cylinder liner 85RC6 

O-ring 3.53x91.67 

Discharge valve ring and spring(s) Option L 

Discharge valve ring and spring(s) Option H 

Suction valve ring, spring and damper ring 

Source of table below; 00.87.315 


01.10.540 

11.13.501 

27.36.410 

11.33.087 

27.36.113 

27.36.103 

01.45.400 

11.13.401 

* 

* 

* 

* 

* 

* 

* 

* 

09.52.362 

23.36.120 

09.52.361 

11.34.110 

11.34.105 

11.34.115 

4 

4 

1 

1 

1 

1 

1 

1 

1 

1 

2 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

Option ’L’(Low) 

Option ’H’(High) 

Option ’L’ (Low) 

Option ’H’(High) 

refer 

table 

below 



Grasso 

RC6-5H RC6-5L 




Grasso 







ROTARY SHAFT SEAL FIG. RC6-6 

1 

2A 

2B 

3 

4 

5 

6 

7 

Shaft seal housing RC6 

Plug G13S 

Plug NPT13 

Nipple coupling 6N10 

O-ring 3.54x158.34 


Washer M10 

Shaft seal assy 54RC6 

26.36.100 

01.36.134 

03.65.513 

03.38.810 

09.52.364 

01.10.535 

11.13.501 

09.62.900 

OIL PUMP FIG. RC6-7 

1 

2 

3 

4 

5 

6 

7 

Grasso 

Pump cover RC6 

Pump element RC6 

Bearing 


O-ring 3.53x209.14 

O-ring 3.53x136.12 

Pump housing RC6 


26.36.700 

26.36.601 

26.36.710 

01.10.316 

09.52.365 

09.52.363 

26.36.503 

1 

1 

1 

1 

1 

8 

8 

1 

1 

1 

1 

3 

1 

1 

1 from 88.11.2400 




CAPACITY CONTROL MECHANISM FIG. RC6-8 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11A 

11.1A 

11.2A 

11B 

11.1B 

11.2B 

12 

13 

14 

15 

16 

Flange capacity control 

Cylinder head screw M4x10 

Piston 

Compression spring 1.25x10x11.5x51 

Rectangular ring 56x51.3x2 

Washer M10 


Oilit gasket 87x94x1.5 

Cylinder 

Rectangular ring 40x36.6x2 

Solenoid valve 110/120V 

Valve body 

Coil 110/120V 9W 

Solenoid valve 220/240V 

Valve body 

Coil 220/240V 9W 

Connector 


Set screw M5x10 

Socket head scew M8x1 

O-ring 

27.36.702 

01.68.210 

27.36.600 

11.31.132 

09.70.056 

11.13.501 

01.10.540 

09.07.087 

27.36.500 

09.70.040 

* 

* 

13.16.311 

06.80.111 

* 

13.16.322 

13.16.610 

13.16.611 

13.16.615 

03.37.106 

01.23.010 

03.65.708 

09.51.093 

1 

4 

1 

1 

1 

4 

4 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

3 

2 

per controlled cylinder cover 

NH3/R 

for valves 11A/11B, without LED 

With 220 V-AC/DC LED 

With 48 V-AC/DC LED 

OIL DISCHARGE FILTER FIG. RC6-9 

1 

1.1 

1.2 

2 

3 

4 

5 

6 

Grasso 

Filter set 

O-ring 3.53x136.12 

Filter cartridge 480x15 

Hex. nut M6 

Stud M6x20 

Filter housing 130 


Washer M10 


07.11.900 

09.52.363 

* 

01.45.300 

01.51.320 

07.02.130 

01.10.575 

11.13.501 

C10 RC6 0089238-v004.00.02.en 

1 

1 

1 

1 

1 

6 

6


Grasso 






Grasso 


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� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

� 

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� 

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� 

� 

� 

� 

� 

� 

� 

� 

� � � � � � � � � � � � � � � � � � � � � � 

� 

� � � � � � � � � � � � � � � � � � � � � � 

� 

� � � � � � � � � � � � � � � � � � � � � � 

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FLANGED MAIN CONNECTIONS FIG. RC6-10 

1A 

1B 

1C 

2 

3 

4 

Shoulder flange RC46 




Oilit ring 67x81x1.5 

Relief valve 

05.39.045 

05.39.051 

05.39.063 

01.10.840 

09.03.067 

12.49.333 

1 

1 

1 

4 

1 

per flanged connection 

per flanged connection 

SUCTION GAS STRAINER FIG. RC6-11 

1A 

1B 

2 

3 

Grasso 


Shoulder flange RC66/RC86 

Oilit ring 67x81x1.5 

Wired mesh filter 544x100 


05.39.048 

05.39.060 

09.03.067 

07.16.544 

0089238-v004.00.02.en RC6 C13 

1 

1 

2 

1



OIL SUCTION FILTER FIG. RC6-12 

1 

2 

Oil filter 149x16 

Swivel coupling 16G21 

07.16.164 

03.39.216 

1 

1 

from 95.08.1648 

OIL DIFFERENTIAL PRESSURE SAFETY SWITCH FIG. RC6-13 

1 

2 

3 

4 

5 

6 

7 

8 

Oil pressure safety switch 

Bracket 63x115 

Angle coupling 6x6x6 (complete) 

Socket coupling 6G17 (complete) 

Union nut 

Steel precision pipe ø6x1 mm 


Clamp but sleeve P6 

12.60.232 

12.61.232 

* 

03.40.406 

03.37.176 

03.10.006 

* 

03.38.106 

* 

1 

1 

1 

2 

2 

6 

2 

1 

8 

NH3 

R 

Possibly 6N13 (03.38.813) or 6G13 

(03.38.136) are applied 

OIL PRESSURE REGULATOR FIG. RC6-14 

1 

1.1 

1.2 

1.3 

1.4 

1.5 

1.6 

1.7 

1.8 

1.9 

2 

3 

Grasso 

Oil return line SAM RC6 

Steel precision pipe K12x1.5 and valve housing 

Alu sealing ring 21.5x27x1 

Ball W16 

Spring 1.25x14x9x35.5 

Thrust bolt G21x60S 

O-ring 1.78x8.73 

Nipple G21CxG21 


Cap nut GK21R 




12.41.140 

12.41.012 

09.12.022 

11.19.010 

11.31.134 

01.35.218 

09.52.184 

03.04.921 

09.12.010 

01.17.021 

---------- 

---------- 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

lubricating oil pressure regulator 

included 

refer to fig. RC6-6 

refer to fig. RC6-1 



1 

Grasso 


1.1 

3 

2 

1.2 


1.3 1.4 1.5 1.6 1.7 1.8 1.9 






STANDARD SETS OF PARTS, SEALS AND TOOLS FIG. RC6- (no figure) 

1 

2 

3 

4 

Grasso 

Set of gaskets and seals 

Set of spare parts (containing valve rings and 

sinusoidal springs) 

Set of basic spare parts 

Tire clamp (coupling tool) 


09.90.046 

09.90.066 

09.90.086 

* 

* 

15.08.232 

15.08.244 

15.08.280 

1 

1 

1 

1 

1 

1 

1 

1 

for RC46 



for all types 

for coupling element 42 





The illustrated parts list of the accessories on the following pages is meant for identification and 

accurate specification of current spare parts. In order to facilitate quick retrieval of the required parts, 

the list and corresponding figures is divided into the following groups of parts: 

GROUP OF PARTS 

Grasso 

PARTS LIST 

Page 

CORRESPONDING FIGURE 

No.: 

o Pressure gauges and safety switches 2 RC6-A1 

o Direct drive 5 RC6-A2 

o Cooling water device 6 RC6-A3 

Figures 

All parts shown in the figures bear an item number. 

Assemblies are indicated by a dotted frame with 

separate item number around the parts included in 

that particular assembly; 

the parts themselves bear the same item number, 

followed by a sequence number (e.g. 2.1, 2.3, 2.3, etc.). 

Parts lists 

The parts are specified by the headings “Item”, 

“Description” “Ref. no.” and “Qty” (= Quantity). 

* If an asterisk is used instead of the Ref. no., this means 

that the relevant part cannot be obtained separately. 

When for some part no quantity has been given, the 

quantity required depends on the compressor size. 

When determining the required quantity of parts, it 

should be considered that the listed quantities relate 

to the corresponding figure and not to the compressor 

as a whole. When ordering, for example, valve 

rings for two discharge valves, the quantities stated 

in the relevant list must be doubled, because these 

apply to one discharge valve only. 


This is a RC6 compressor, including water cooled cylinder 

heads 

How to order! 

It is emphatically pointed out that a prompt despatch of the correct spare parts can be 

guaranteed only if the following information is given: 

1. Type designation of the compressor 

shown on the compressor name plate 

2. Serial number of the compressor 

3. Quantity, Description and Ref. No. of the required parts. 

PARTS LIST RC6 

ACCESSORIES 

v002.99.05.en RC6 Accessories 1



PRESSURE GAUGES AND SAFETY SWITCHES FIG. RC6-1A 

1a Pressure gauge and safety switch cabinet NH3 - std 12.08.301 1 with two safety switches 

R22 - std 

12.08.601 1 with an additional safety 

R134a - std 12.08.701 1 switch to meet German 

R404A - std 12.08.801 1 UVV-VBG20 regulations 

1b 

1.1 

1.2 

1.3 

1.4 

1.5a 

1.5b 

1.6 

Grasso 

Pressure gauge and safety switch cabinet NH3 - UVV-VB420 

Pressure gauge discharge pressure NH3 - R-P-63 

R22 - 63 

R134a - 63 

R404A 

Pressure gauge suction pressure NH3 - R-Z-63 

R22 - Z-63-12 

R134a - Z-63-12 

R404A - Z-63-12 

Pressure gauge oil pressure R-O-63 

Oil pressure safety switch type NH3 MP55A 

R MP55 

Combined suction and discharge pressure safety switch type 

NH3 KP15A 

R KP15 

Combined discharge pressure limitor and safety switch type 

NH3 kP7ABS 

R kP7BS 

Suction pressure safety switch type NH3 KP1A 

R KP1 

12.08.302 

12.08.602 

12.08.702 

12.08.802 

12.10.065 

12.12.065 

12.12.066 

12.12.067 

12.10.066 

12.12.068 

12.12.069 

12.12.070 

12.15.065 

12.60.232 

12.61.232 

12.60.615 

12.61.615 

12.60.618 

12.61.618 

12.60.608 

12.61.608 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 


ACCESSORIES 

Accessories 2 RC6 v002.99.05.en


Grasso 


ACCESSORIES 

RC6-1A 



2 

Grasso 

1.1 

1 

electric 

motor 


ACCESSORIES 

compressor 





DIRECT DRIVE FIG. RC6-2A 

1a Coupling type 42 (complete) 

* 1 to facilitate mounting, a steel strip 

1.1a Coupling element 55 

19.18.842 1 is clamped around the coupling 

1b Coupling type 61 (complete) 

* 1 element, which must be removed 

1.1b Coupling element 80 

19.18.861 1 before putting the compressor into 

1c Coupling type 91 (complete) 

* 1 operation 

1.1c Coupling element 120 

19.18.891 1 

2 

Grasso 

Clamping sleeve 

* 

1 


ACCESSORIES 




COOLING WATER DEVICE FIG. RC6-3A 

1 

2 

3 

4 

5 

6 

6.1 

7 

8 

9 

10 

Grasso 

Hose, rubber 19W 

Hose clamp 19-28 mm 

Spigot nipple 19xG21 

Angle socket coupling G21xG21 

Socket nipple G21xG42 


Clamping sleeve P16 

Coil cooler 16x1.5x64x280 

Water cooled cylinder cover without control 

Water cooled cylinder cover with control 

Side cover for oil cooler coil 

15.18.019 

15.08.600 

15.55.419 

03.72.441 

03.02.471 

03.38.212 

03.34.516 

04.10.364 

23.36.505 

23.36.515 

05.30.178 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

1 

twice per hose 

per cyl. head cover connection 

per coil connection 


ACCESSORIES 



Grasso 


ACCESSORIES 




Grasso 


ACCESSORIES 



Grasso

Please contact your office: 

Grasso Products B.V. P.O. Box 343 • 5201 AH ’s-Hertogenbosch • The Netherlands 

Phone: +31 (0)73 - 6203 911 • Fax: +31 (0)73 - 6231 286 • E-Mail: products@grasso.nl 

Grasso GmbHHolzhauser Straße 165 • 13509 Berlin • Germany 

Refrigeration Technology Phone: +49 (0)30 - 43 592 6 • Fax: +49 (0)30 - 43 592 777

RC(U)6 Installation and Maintenance Manual - Marine Refrigeration ...

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