System 27 NOVA Modular Electronic Humidity ... - ShanControls

PSC9717 

European Refrigeration Controls Catalogue 

Catalog Section 2 

Product Bulletin W27 

Issue 9705 

System 27 NOVA 

Modular Electronic Humidity Control System 

I ntroduction 

System 27 NOVA is a family of modular 

electronic modules designed for a wide variety 

of control configurations in refrigeration, 

heating, ventilation, air-conditioning and other 

related fields. 

The humidity control modules can be used as a 

stand alone device or in conjunction with other 

modules such as display modules, signal 

converter modules etc. to achieve a wide 

variety of single or multiple stage applications. 

Typical applications are: 

- computer rooms; 

- clean rooms; 

- fruit storage/ripening; 

- food processing; 

- industrial processes. 

System 27 NOVA Modular 

Humidity Controls 

D escription 

The modular concept was specially designed to 

make control configuration easier and still offer 

the flexibility necessary to answer the many 

individual control requirements encountered 

today. 

Feature and Benefits 

q Modular design 

q “Plug-in” quick connector 

wiring system 

q Adjustable differential and 

humidification/dehumidification 

setting 

q Interchangeable humidity 

transmitters with different 

housings 

q Attractive DIN-rail mount 

housing 

q Setpoint shift output function 

Provides the flexibility to realise the required 

control set up without redundancy and makes 

future expansion easy. 

Eliminates wiring between modules and 

reduces installation cost. 

Provides flexibility to match any combination 

of heating or cooling applications. 

Matches various applications. 

Easy and quick to install. 

Modules can be used for “multiple setpoint” 

applications. 

© 1997 Johnson Controls Inc. Catalogue Section 2 

Order No. PD-W27-E

2 

W27 

Issue 9705 

The System 27 NOVA family includes the 

following modules: 

W27 Humidity Control Modules 

These one- or two-stage 

humidity control modules 

can be used as a low cost 

control for stand alone 

applications or, when 

connected in parallel, for 

multistage applications. The 

control output(s)is a 

single-pole, double-throw 

(SPDT) relay with LED 

indication. It features humidification and 

dehumidification modes of operation and an 

adjustable differential. 

Y27M Signal Converter 

This module converts a 

voltage input signal to a 

standardised output signal of 

0 to 10 Vdc or 

4 to 20 mA. The input signal 

can either be obtained from 

a humidity sensor or a 

humidity control module. 

The signal converter can be 

used for those applications 

where an analogue output is required. Such as; 

to a motor, motor actuated valve, recorder etc. 

D27W Humidity Display Modules 

HT-9000 Humidity Sensor 

A display connected to a 

humidity control module 

gives a digital indication of 

the measured humidity or 

setpoint. It is also possible 

to connect a sensor 

directly to the D27W (the 

sensor is powered by the 

D27W). 

Two types of display 

modules are available: 

* The DIN-rail mount display can be connected 

to a humidity control module very easy by 

using the quick connector system. 

* The panelmount display can be used in any 

application where remote reading of the 

humidity is required. (The panelmount display 

has no setpoint read-out possibility) 

Both types incorporates a 3 digit LED display. 

Y27C Time Switch 

This timing device can be 

used for a large variety of 

applications where a time 

based digital output is 

required. The time switch 

contains two SPDT 

contacts which can be 

programmed individually. 

Sensors are available for room, duct or build-in 

applications. Please refer to the HT-9000 

humidity sensor bulletin. 

N ote 

These controls are designed for use only 

as operating controls. Where an operating 

control failure would result in personal 

injury or loss of property it is the 

responsibility of the installer to add 

devices or systems that protect against, or 

warn of, control failure. 

Catalogue Section 2 

© 1997 Johnson Controls Inc. 



Issue 9705 

Application examples 

At page 5 to 7 you will find some applications 

examples. For more detailed information about 

wiring and adjustment reference should be 

made to the installation sheets. 

Repair and replacement 

Repair of the System 27 NOVA modules is not 

advisable. In case of a defective or improperly 

functioning module, check with you nearest 

supplier. When contacting the supplier for a 

replacement just state the type/model number 

which can be found on the data plate of the 

module. 

Accessories dim. in mm 

30 

Fig. 1 

WRE027N600 

Quick Connector for connecting System 27 

NOVA modules. 

3 

Dimensions (mm) 

25 

Fig. 2 

PLG020N003 

Plastic plug for concealed setting 

27 

118 

45 

83 

12 

5 

43 

53 

20 

70 

Fig. 3 

System 27 NOVA Modules 

86 

8 

96 

18 

42.5 

48 

20 23 

89.5 

Fig. 4 

Panelmount Display and Display/Selector Module 



4 


Issue 9705 

Type Number Selection Table 

W27 Humidity Control Modules 

One Stage Humidistat 

Order 

number 

Power 

supply 

Setpoint range 

Additional 

W27N11 24 V ac/dc 10 to 100% R.H. * Mode: field adjustable 

W27N21 230 V ac * Differential: 2 to 10% R.H. 

* SPDT contact 10(5)A 250 V ac 

* Setpoint shift: 0 to 20% R.H. 

Two Stage Humidistat 

Order 

Power Setpoint range 

Additional features 

number supply 

W27N12 24 V ac/dc 10 to 100% R.H. * Mode: field adjustable 

W27N22 230 V ac * Differential: 2 to 10% R.H. 

* 2x SPDT contact 10(5)A 250V ac 

* Setpoint shift: 0 to 20% R.H. 

Humidity Display Modules 

Order 

number 

Power 

supply 

Enclosure 

quick 

connector 

incl. 


D27W1N4 24 V ac DIN rail mount no * Can be used as stand alone or in 

D27W2N4 230 V ac DIN rail mount no conjunction with a humidity 

D27W2N4Q 230 V ac DIN rail mount yes control module 

D27WB-9100 24 V ac Panelmount no * Display range: 0 to 100% R.H 

D27WF-9100 230 V ac Panelmount no 

Y27L Signal Converter 

Order 

Power supply Setpoint range (V) Span range (V) 

number 

Y27M1 24 V ac 0 to 10 0 to 10 

Y27M2 230 V ac 0 to 10 0 to 10 

Y27C Time Switch 

Order 

Power supply 


number 

Y27C1 24 V ac * 2x SPDT contacts 10(5)A 250 V ac 

Y27C2 230 V ac * 12 programmable on/off positions 

* Week program 

* Two channels 





Issue 9705 

5 

One-stage Humidistat 

W27Nx1 

Wiring & Adjustments 

Two-stage Humidistat 

W27Nx2 

A B C S 

A B C S 

A B C S 

R 

Mode 

selector 

Setpoint 

on 

Diff. 

off 

off 

Diff. 

on 

Mode 

selector 

A B C S R 

Setpoint 

off 

Diff. 

on 

off 

Diff. 

on 

1 2 

stage 

Mode 

selector 

Setpoint 

Setp. 

on 

Diff. 

off 

on 

Diff. 

off 

1 2 

stage 

Setp. 

3 4 5 

1 2 

6 7 8 

3 4 5 

1 2 

Humidity/Display module 

D27WxN4 

Signal Converter Module 

Y27Mx 

Common 

Voltage output 

Current output 

A B C S 

A B C M N 

Span adj. 

A B C S 

Reading out 

a humidistat 

DA RA 

A 

B C M N 

20 mA/10V 

Output 

4 mA/0V 

Reading out 

a sensor 

(stand alone) 

Reverse acting 

1 2 

20 mA/10V 

20 mA/10V 

Output 

Input 

4 mA/0V 

4 mA/0V 

Setpoint 

adj. 

Input 

1 2 

Direct acting 



6 


Issue 9705 

Programmable Time Switch Module Y27C 

1 2 3 4 5 6 7 8 9 1 0 11 12 

Prog 

+ 1h 

1 

2 

I 

0 

I 

0 

I 

0 

1 

Day 

Re set 

1 2 3 4 5 6 7 

2 

3 4 5 1 2 6 7 8 

A pplications 

Two stage humidity control 

Three stage humidity control 

A B C S 

R 

A B C S 

A B C S 

R 

A B C S R 

3 4 5 1 2 6 7 8 

1 2 

3 4 5 1 2 6 7 8 

3 4 5 

1 2 

~ 

0 

~ 

0 

Stage 1 Stage 2 

Stage 1 Stage 2 

Stage 3 





Issue 9705 

7 

One stage humidity control with read-out and analogue out-put 

0 to 10V 

analogue 

output 

A B C S R 

A B C S 

A 

B C M N 

3 4 5 

1 2 

1 2 

1 2 

~ 

0 

Humidification or 

Dehumidification 



8 


Issue 9705 

General System 27 NOVA 

S pecifications 

Outtput relay rating SPDT 10(5)A 250 V ac 10 A 30 V dc 

Operating ambient -10 to +50 °C 

temperature 

Storage temperature -40 to +70 °C 

Operating (storage) R.H. 10 to 90 % R.H. (non condensing) 

Terminals screw type max. wire thickness 2,5 mm 2 

Power supply 

230 V ac +10% / -15% ; 50/60 Hz 

24 V ac/dc +10% / -15% ; 50/60 Hz 

Additional specification for display modules 

Power supply 

Resolution 

Accuracy 

230 V ac +10% / -15% ; 50/60 Hz 

24 V ac +10% / -15% ; 50/60 Hz 

1% R.H. 

± 2% R.H. 

Signal converter 

Time switch 

Power supply 

Output load 

Back up power 

Operating reserve 

Operating accuracy 

Switching accuracy 

On/off positions 

Min.time between switch 

positions 

230 V ac +10% / -15% ; 50/60 Hz 

24 V ac +10% / -15% ; 50/60 Hz 

voltage output Rmin = 1 k Ω 

current output Rmax = 500 Ω 

NC accumulator 

approx. 500 hours (after 100 hours on power supply) 

approx. 1 sec/day 

1 sec 

12 free programmable 

1 min 

The performance specifications are nominal and conform to acceptable industry standards. For applications at conditions beyond 

these specifications, consult the local Johnson Controls office or representative. Johnson Controls shall not be liable for damages 

resulting from misapplication or misuse of its products. 

Johnson Controls International, Inc. 

Headquarters: 

Milwaukee, WI, USA 

European Headquarters: Westendhof 8, 45143 Essen, Germany 

European Factories: Lomagna (Italy), Leeuwarden (The Netherlands) and Essen (Germany) 

Branch Offices: 

Principal European Cities. 

This document is subject to change 

Printed in Europe

System 27 NOVA Modular Electronic Humidity ... - ShanControls

Create successful ePaper yourself

Delete template?

Save as template?