Central ventilation with heat recovery unit KWL 250 - HELIOS ...

Central ventilation with heat recovery unit KWL 250
Operation and installation instructions no. 91581
It is important for safety reasons and to ensure a satisfactory operation, that
you read and observe this instruction fully before proceeding!
RECEIPT
The cardboard box conatains one of the following items, including a three step
operation switch:
KWL 250 Ref.-No. 850.001
KWL 250 EH (with electric heater battery) Ref.-No. 850.010
KWL 250 WW (with water heater batery) Ref.-No. 851.001
Please check delivery immediately on receipt for accuracy and damage, please
notifiy carrier immediately. In case of delayed notification, any possible claim may
be void.
STORAGE
When storing for a prolonged time the following steps are to be taken to avoid damaging
influences: protection by dry air and dustproof packing (plastic bags with
drying agent and moisture indicators). The storage area must be free of water, vibration
and temperature variations.
When storing for several years with non rotation of motor an inspection of the bearings
with possible relubrication and an installation inspection in accordance with
VDE 0530 are absolutely necessary before starting operation. Damages due to
improper storage, transportation or installation are not liable for warranty.
OPERATION / USE
The unit is designed to ventilate a combination of living rooms, bathrooms and kitchens
in a single storey dewelling up to120 m 2 . The unit is equipped with a heat
recovery battery. It must not be connected to kitchen hoods or laboratory extract
fans. The standard equipment allows a working temperature range from -20°C up
to 40°C. For operation under difficult conditions, e.g. high humidity, long periods
of standstill, high air pollution or through climatic (e.g. operating temperature over
40°C), technical or electronic influences other than standard operations may not
be suitable. For this reason please enquire and obtain operation release. A release
by a third party is not valid.
MODE OF ACTION
In the heat exchanger the cold outside air and the warm extracted air "crosses over"
without touching. Through this exchange the energy of the warm air is tranfered to
the incoming air. Additionally a thermostat controlled heating element warms up the
inlet air (in extreme cold weather conditions) to the required temperature. The inlet
air is directed to the living rooms and bedrooms through ducting and valves. The
used air is extracted from the bathrooms, toilets and kitchens. It flows back to the
fan via the ducting systems, transfering heat before being released into the open air.
PERFORMANCE DATA (Picture 1, Page 1)
To achieve the given performance, the unit must be correctly installed. Varying
from the design and/or installation requireements and also by incorrect operation
can lead to a reduction in the unit capacity. Noise figures are stated in sound power
levels L WA in dB(A) (conforms to DIN 44635 T.1). Sound pressure levels L PA
depend on room specific conditions. These conditions may affect the measured
result on site and vary from the catalogue data.
INSTALLATION-ASSEMBLY (Picture 2, Page 3)
The KWL 250 is suitable for „hanging“ arrangement for installation in a cupboard
or for installation on a wall and therfore for installation within the room of the dewelling.
There are drilled holes for wall installation at the level of the air connecions.
For wall installation a support plate to hang the unit on is included. If a wall installation
is not possible, the unit can also be fixed through its side panell into the ajoining
surface. When screwing through the side panel, the fans, controler, heating
element and electrical wiring must not be damaged or restricted in function.
Sound and vibration transfer must be considered on site when installing the unit. It
is necessary to connect the condensation spigot of the unit to a pipe connected
to the drainage system of the house with a U bend trap in to prevent oders returning
from the drains (see condensation run-off). The condensate pipeing must ensure
the effective gravity flow of the condensate water. Tight bends can lead to a
high pressure loss and flow noise. A secure and tight connection of the ductwork is
required. For maintenance and installation work, the unit must be accessable.
When taking the unit out of the carboard box, the unit must not be stod on the
condensation spigot at the bottom of the unit. Therefore lay it on its back to prevent
damage, using the polystyrene packing to lay the unit on will ensure the unit
will not get scratched. Before installation the operation switch must be taken
out of the unit.
– CONDENSATION RUN-OF (Picture 2 and 3, No. 4)
To prevent siphioning and oders the condensation pipe should have a ‘U’ bend
trap in the line. It must have a minimum height of 100 mm, otherwise water could
be drawn back through the fan.
NB: To avoid odours, fill in water in the drain trap before putting into operation.
For trouble free operation, the drain must incline and the condensation
spigot under the tray should be mounted low enough.
The regulations of the water board and other legislation must be observed.
The condensation spigot is to be fixed to the drainage system via a flexible hose
∅ 15 mm. If the same is not in a room which is heated, it must be protected
against frost.
– AIR DUCTING, VENTILATION CIRCUIT
When designing the ductwork, use the shortest possible runs. Airight connections
and change overs must be ensured for the best possible heat recovery. To avoid
pressure loss, accumulating dirt, and noise, use smooth ducting (plastic or rigid
ducting). For main ducting (outside air, extract air, inlet air, discharge collection) a
diameter 125 mm has to be used, for side ducting use a diameter of 80 mm to
125 mm.
To reduce condensation in the extract and outside air pipes, the ducting has to
be insulated where appropriate. Also if inlet and extract ductwork cross unheated
rooms insulation must be provided to reduce heat losses.
Fresh air should be supplied into living and bedrooms, extraction takes place in
bathrooms, toilets and kitchens. To balance the whole system the duct connection
into the rooms we recommend the use of adjustable valves (HELIOS-valves).
The opening for the kitchen extract needs a filter. A kitchen hood must not be
connected directly to theKWL 250 unless adequate protection is provided to
precvent grease build-up. Extract air from kitchen hoods with a own fan must be
extracted via a seperate duct. There must be enough air transfer flow between
rooms (e.g. door grilles) within the building to guarantee air flow between intake
rooms and extract rooms.
Fire and building regulations must be observed.
– Sensor heater battery (KWL 250 EH) (Picture 3, No.17)
The temperature sensor for the suppy air must needs to be mounted into the supply
air duct after the unit’s outlet. A hole of Ø 7 mm is required, insert the temperature
sensor, fixand fix ensuring an airtight seal.
– ELECTRICAL CONNECTIONS (Picture 5, Page 5)
Only work with the unit isolated from the electric supply. An isolator is required for
with a minimum of 3 mm contact opening of each pole. Electrical connection
should only be carried out by a qualified person.
All relevant safety and installation regulations (IEE regulations) are to be observed.Between
the circuit board and the terminal box of the operation switch a
control cable (8 x 0,25 mm 2 , length max. 50 m) is to be used.
Electrical connections are to be made using to wiring diagram SS-762.
The unit is supplied with a power lead with three pin plug. Normally the unit does
not have an "off"-state. If necessary plan a switch before the power socket. After
mounting of the unit the plug must be easily accessible.
If this is not the case, an on/off switch with 3 mm contac distance must be installe
(VDE 0700 T1 7.12.2). For a good room climate and to avoid damages due to
condensation, the KWL 250 should never be switched off completely, appart from
the time for maintenace and repair or malfunctions.
∆ p fa
[Pa]
– FIREPLACES & BOILERS
The central ventilation unit with heat recovery “KWL 250“ will create a negative pressure
with in the dewlling in certain areas. Steps should be taken to ensure that the negative
pressure created will not restrict the airflow to gas, oil of solid fuel devices. It may
be necessary to fit a makeup air unit suvh as an airbrick or a Helios ZLA or ZLE unit.
Picture 1
V [m 3 /h]

Central ventilation with heat recovery unit KWL 250
Operation and installation instructions no. 91581
INSTALLATION OF CONTROL CABLE
The control cable should be shielded and not be placed parallel to the mains supply
cable as interference may cccur.
OPERATION – ADJUSTMENT
The KWL 250 is to be controlled manually via the operation switch, which should
be mounted on a convenient place in the house. The operation switch allows following
functions:
– right press button (fan symbol): the desired step for the air flow volume can be
adjusted, the according light shows the chosen step:
MIN (speed step 1) basic air flow, for less intake air needs
NORMAL (speed step 2) normal air flow
MAX (speed step 3) full R.P.M., for maximum intake air needs
– left press button (+ symbol) only important in combination with electric heater
battery: The electric heater battery can be switched on and off. When switched
on, the heater battery starts heating when the temperature is lower than the temperature
pre set point (adjusted on the pot.)
red light (!)
blinking slow Filter needs to be changed ! (if filter monitor is installed)
blinking fast The temperature monitor (Pic .3, No.2.2) for the heater
battery tripped.
blinking constant Both messages appeared..
green light (+) blinking, when availability of heater element is switched
on,
yellow light (°C) Blinking, when electric heater battery is in use.
Speed step 2 can be adjusted to the size of the dewelling. Open the unit is to be
opened. Then change the two connections, marked with speed step 2 at the
transformer according to wiring diagram in the unit. Isolate from the mains supply
before comencing this work all mains.
Note: If the electrical supply of the KWL 250 is disconnected, the unit will restart
automatically with basic air flow (speed step 1) and the availability of the heater
battery.
N.B.: For good room climate and to avoid damage from condensation, the KWL
250 should never be switched off apart from cleaning/maintenance work or possible
faults.
Settings on DIP-switch
Switch- Standard- Function
No. setting
1 ON ON position: Electric heater battery to be switched off
during frost protection modus. (must not be OFF!)
2 OFF ON position: Electric heater battery to be switched off on
speed step 1.
3 OFF (only with timer) On position:
Supply air to be lowered by 3 °C at night.
(only if a heater battery is used)
4 OFF (only with timer) ON position:
Air flow volume to be lowered on speed step 1 at night
5 OFF –
6 ON –
Setting the electric heater battery (KWL 250 EH)
The pot for temperature preselection fot the heater battery (pic.3, No.1) is placed
on the extract air cover plate. This pot is factory set at 20 °C and can be adjusted
as required for the supply air. Do not set higher than 25 °C. The heating battery is
protected against overheating via a self resetting temperature cut out (pic. 3, No.
2.1). This temperature cutout switches off automatically when the temperature of
65°C has been reached. It switches back on automatically whenf the heater battery
has cooled down. As an additional safety control, a second, non self resetting
thermostat (temperature cut out), switches off the whole unit automatically if a
temperature of 80°C is exceeded. This thermostat can be manually reset by pressing
the reset button, which is accessible by removing the white plastic lid.
Regulating the water heater battery (KWL 250 WW) (Picture 2)
The progressive heating is via the built-in water heater battery (18). The supply
and return pipeing on site must be so routed or fully insulated supply to prevent
frost damage. A thermostatic valve with remote sensor is to be fixed in the supply
pipe of the heater battery on site. The remote controller is to be fixed above the
KWL-connecting spigot “supply air“ into the supply air ducting. Usung the remote
sensor and the thermostatic valve in the water supply the supply air temperature
is controlled. The thermostatic valve is not included and must be supplied and set
on site.
A water control system which is a Helios accessory (ref. WHST 300) is shown in
picture 2. This provides a complete control for the water supply and return.
ATTENTION: If the supply air ducting is to pass through cold areas Insulation must
be applied to prevent temperature losses on before entering the room being supplied.
Frost protection of the water heater battery (Picture 2)
Intake and extract ductwork must be insulated to avoid ice build up on the water
heater battery. Immediately after the water heater battery there is a frost protection
thermostat (20). If the temperature off the water heater battery is lower than to +5
°C the thermo sensor closes. This volt free contact of the thermostat is to be
connected with the heater control so that the shunt valve opens as soon as the
heater and circulating pump are switched off. This forced control avoids the ice
build up on the water heater battery. If the unit is switched off at any time in winter
the warn water coil should be drained off to prevent frost damage to the coil.
Frost protection of the heat exchanger battery:
The sensor (Picture 3, No. 3) for frost protection is located in the extract air ducting.
This sensor controls the supply air fan so that ice and frost can not build up in
the extract air ducting or the heat exchanger. Warm air e.g. from the bathroom
etc. contains high humidity that can condensate easily. Therefore the temperature
in the heat exchanger must not drop so low that water freezes in it. When the outside
temperature drops the extract temperature drops as well. If the temperature of
the extract air is close to the freezing point, the supply air fan switches off for a
certain period of time until the heat exchanger is warms up sufficienty. The frost
protection thermostat is factory set and normally needs no adjustment.
– Summer Service
During the warmer months (apart from the heating period) it is not necessary to recover
heat. The recovery battery can be replaced with a summer insert (Accessory KWL-
SOE 250, Ref. No. 0855). Through this the outside air enters directly into the house
without being warmed up. The temperature adjusting pot (KWL 250 EH) or the thermostat
(KWL 250 WW) must be positioned on low temperature otherwise unnecessary
heating will be the result. Remember to reset the thermostat the following autumn
and replace the heat exchanger unit again.
– Accessories, switches, controllers
It is not admissible to use accessories which are not recommended by Helios, in
case of damage this will lead to a loss of warranty. The use of an electronic or
transformer speed controller is not permissible.
CLEANING AND MAINTENANCE
Isolate the unit from the electric supply before carring out any work on the unit.
– Opening of door (Pic. 3, page 4)
The door is secured with screws and can be opened after removing the screws.
– Filter
The unit filters are as follows:
• Outside air: Prefilter G 3 Part.-No. 0043
Finefilter F 5 Part.-No. 0044
alternatively: (F 7, Part.-No. 0045, eg for persons with allergies)
• Extract air: Prefilter G 3 Part.-No. 0043
The outside air and the extract air filter are to be checked and changed regularly,
depending on degree of pollution at least every 3 months. For hygiene reasons,
the fine filter should be changed after every year at least. Check the correct the air
flow direction when refitting the filter. In areas of heavy air pollution, a filter box
(LFBR 125, Part.-No. 8577) should to be placed in an easily accessible area upstream
of the unit. These filters must be regullary cleaned and changed.

Central ventilation with heat recovery unit KWL 250
Operation and installation instructions no. 91581
– Filter control
A filter control is not provided as standard. If it is required, a differential pressure
switch (as accessory obtainable DDS switch, Ref.-no. 0445) can be connected to
the KWLC. The holes for the pressure hoses (see picture 4) are in the casing (see
picture 4). One connection point is in the top of the casing the with the other the
pipe passing through the top of the casing to the connection pointin the side of
the extract chamber. The link must be removed on the "FI" circuit boardand the
DDS connectoins made as shown..
– Fans
The fans are to be maintained and cleaned every 12 months at least. For cleaning
use a small brush and an oil free cleaning fluid. Make sure that no water gets into
the motor. Fan must be completely dry before re-using.
To dismantle the unit, screw of the cover plate extract air (pic. 3, No. 15) or supply
air (pic. 3, No. 16), disconnection of the plug connectors, pulling of the fans to
the front. Than disassemble impeller from casing.
– Heat recovery battery
To be cleaned at least twice a year. Pull out the unit carefully. For cleaning put in
warm soapy water (do not use cleaning fluids that can damage the aluminium or
leave residual oders/gases) and finally clean with warm water. When re-assembling
ensure correct installation.
• Make sure that summer-insert was exchanged for the heater recovery element.
– Substantially reduced air flow
• Filters (6 and 7) could be dirty. Change or clean filoters (see maintenance)
– Water emission out of unit
possibly the condensation water can not drain off properly.
Reasons for this problem:
• Condensation drain is blocked up or not drainging properly (check installation).
• Condensation gathering in the tray, because the condensation spigot has
been pushed to the top/ into the unit (e.g. by standing the unit on the con
densation out let pipe in the bottom during inatallation).
Corrective: Take heat exchanger from the unit and move the condensation spigot
softly downwards.
Having tried the above solutions, if the problem still exists the contact your installer/supplier
giving the serial number from the unit’s nameplate.
– Valves: To be cleaned at least annually.
– Outer grilles: Check yearly that grilles are free from leaves etc.
SOURCES OF MALFUNCTION
Prior to working on the unit ensure it is isolated from the electrical mains
supply.
– No air flow
• Check electrical connection / fuses
• The overheating thermostat 2.2 may have tripped. Remove white plastic cap
and press red button.
– Inlet air is cold
• Set heater thermostat (1) to a higher temperature
• Ductwork in cold areas need extra insulation
Picture Abb. 2 2
General arrangement
Floor (fire protection)
Water control for KWL 250 WW
ventilation duct/
ceiling
operation switch
extract air
outside air
Shunt valve
Thermostatic valve
with remote sensor
in the supply duct
Input air
extract
air
outside
air
extract air
Condensate pipe 15mm
in a frost free area
Drain pipe
to heating system
warm water
from heating system
Min.
100mm
Condensate trap
in a frost free area
pump
heating
control
Volt free contactor
(closed) T2 for
frost protection
Warm Water
(WW) Battery
Floor (fire protection)

Central ventilation with heat recovery unit KWL 250
Operation and installation instructions no. 91581
Picture Abb. 3 3
1 Temperature-Pot (Version EH)
2.1 Temperature cut out self resetting
(Version EH)
2.2 Temperature cut out not self resetting
(Version EH)
3 Frost thermostat for heat exchanger
4 Condensate outlet
5 Extract pre filter G3
6 Inlet pre filter G3
7 Inlet fine filrter F5
8 Elecrtic heater (Version EH)
9 Supply fan
10 Extract fan
11 Heat exchanger
12 Terminal box
13 Operation switch
14 Door
15 Cover plate extract air
16 Cover plate supply air
17 Temperature sensor supply air
18 Warm water heater battery (Version WW)
19 Flow & return pipes for the warm water(Version WW)
20 Temperature sensor for frost protection ofthe water
heater battery (Version WW)
Parts identification
Input air outside air
extract air extract air
Duct connections
Room side Outside
Input air
extract air outside air
extract air
Picture Abb. 4 4
Hole 7mm dia for DDS
12 mm pipe connections for
the warm water coil
(WW version only)
Input air
extract air
outside air
extract air
Connection hole for DDS
7mm dia hole for DDS
Hole for operation
switch cable
Input air
extract air
outside air
extract air
Condensate outlet 15mm

!
Central ventilation with heat recovery unit KWL 250
Operation and installation instructions no. 91581
Picture Abb. 5 5
KWL
250 EH
SS-762
Klemmenadapter
Terminalblock
-orange
-blue
-green
-brown
-yellow
-red
-white
-black
or
bl
gn
br
ge
rt
ws
sw
123 4 5 6 7 8
/optional
wahlweise
8 x 0,25 mm² max. 50m
or
bl
gn
br
ge
rt
ws
sw
Datenleitung mit RJ45-Stecker (Adern "gedreht")
Dataline with RJ45 plug (wires rotated)
1
2
3
4
5
6
7
8
Steuerplatine Heizung / Heater element
Betriebsschalter
Circuit board
for/ bei KWL 250 optional:
Main switch
EHM 250
MIN
NORMAL
MAX
/ Ref.no.
Standardeinstellung,
siehe Montageanleitung
°C
Best.Nr.
0853
for/ bei
KWL 250 WW
bei
KWL 250 EH
for/
2 3 4 5 6
1
N
on
off
/ incl.
PWW inkl.
/ incl.
inkl.
KWL-WSU Best.Nr. 0856
Wochenzeitschaltuhr
Nachtabsenkung,
optional
88
88
Frostschutzthermostat
Warmwasser
potentialfrei
L
For switch settings
see operation and
maintenance manual
Frost protection thermostat warm water
Volt free contact from thermostat
FI
Weekly timer, night set back
(lowers temperature at night)
optional
KWL 250
/ Mains supply
Netzstecker
Externes
Temperaturmodul,
optional
External temperature module
optional
15
20
10
PE
N
L1
P
P
/Ref.no.
25
5
2
1
DDS
Best.Nr.
0445
Drucksensor
°C
Trennschalter / On/off switch
optional, VDE 0700 T1 7.12.2
/Differential
pressure switch
optional
92818 002 SS-762 04.02.04

Central ventilation with heat recovery unit KWL 250
Operation and installation instructions no.
Druckschrift-Nr. 91581/ 09.03
Service und Information
D HELIOS Ventilatoren GmbH & Co · Lupfenstraße 8 · 78056 VS-Schwenningen F HELIOS Ventilateurs · Z.I. La Fosse à la Barbière · 2, rue Louis Saillant · 93605 Aulnay sous Bois Cedex
CH HELIOS Ventilatoren AG · Steinackerstraße 36 · 8902 Urdorf / Zürich GB HELIOS Ventilation Systems Ltd. · 5 Crown Gate · Wyncolls Road · Severalls Industrial Park ·
A HELIOS Ventilatoren · Postfach 854 · Siemensstraße 15 · 6023 Innsbruck Colchester · Essex · CO4 9HZ