Airflow AIROVENT MEV WH4B Operation manual

80001184 –Issue 1 02/22
Installation / Operation and Service
Guide
MEV WH4B & MEV WH6B
Part No`s: 90001495 & 90001496
Central Mechanical Extract Ventilation
Units
90001495
90001496
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Contents
Page 2 of 23
Page Nº Heading
3 Unit Dimensions
4 Unit Specifications
5 Transport and Storage
6 –7 Electrical Installation
8 Wiring Diagram
9 –10 Mechanical Installation
11 –14 Duct Connection
15 –16 Fan Performance Settings
17 Flow / Pressure Graph
18 –19 Service and Maintenance
20 Fan and Packaging Disposal
21 Assorted Accessories
22 –23 Warranty

Overall Unit Dimensions
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Unit Specifications
Voltage Required: 230V –50 / 60Hz –1Ph
Three Fan Speed Bands Available:
Band 1(Low) = Two speeds –87 and
123m³/h
Watts= 5 & 8
Band 2 (Medium) = Eight speeds –97 to 234
m³/h
Watts = 6 To 27
Band 3 (High) = Eight speeds –158 to 335
m³/h
Watts = 12 to 71
Weight: 3.5Kg
MEV WH4 = 3 x 125Ø ports from rooms &
1 x 125Ø to outside
MEV WH4B = 6 x 75Ø ports from rooms &
1 x 125Ø to outside
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Transport and Storage
Units should be stored in their original packaging in
a dry environment protected from the weather. If
palletised quantities are stored or transported, it is
recommended they are covered to protect against
particulate damage and contamination.
Suitable storage temperatures are between –10ºC
and +40ºC.
Care should be taken when re-packing any unit to
ensure the packaging is suitable for the required
form of transport. Damage due to improper
transportation, storage or installation is not covered
under warranty. Care should be taken when lifting.
Correct lifting techniques / apparatus should be
used when necessary. Dropping or sharp blows to
the fan can cause damage. Any damage to the fan
or packaging should be inspected by a suitably
qualified person or returned to Airflow
Developments Ltd for inspection before use.
Fans should not be lifted or carried by an electrical
lead, if fitted.
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Electrical Installation
All electrical installations must be carried out by an
approved electrician in accordance with the latest
IET BS7671 Requirements for Electrical Installation,
Low Voltage Directive 2014/35/EU, Machinery
Directive 89/392/CE or the appropriate regulations
in the country of installation. All fans require a 240V
50/60 Hz single phase supply. Electric circuit to be
used should be isolated before any work is carried
out.
All electrical connections and controls can be found
under the unit’s top protective cover held on with two
large screws. See fig.D page 10. The units electrical
supply cable must be fitted through the cable
retaining path moulded into the unit’s electrical
connection tray. As below.
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Electrical Installation contd.
All cables should be suitably retained and
enclosed where necessary to prevent damage
taking place. A 3 x pole lockable isolation switch with
a 3mm contact gap should be used on the mains
supply to the unit.
The unit should be protected by using a 3amp inline
fuse.
Before function testing the fan, ensure the impeller
runs freely. Function testing should be carried out by
switching the fan on for a short time. When the fan is
running, checks should be carried out for: impeller
rotation direction, undue noise or vibration and
power consumption. Immediately switch off the fan
should any problems be found, and contact Airflow
Developments Ltd. Fan motors used are suitable for
continuous running and have a rated duty type S1
(motor is suitable to this duty type and rating at which
the fan may be operated for an unlimited period).
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Wiring Diagram
230V –50 / 60Hz –1Ph
Airflow Developments fan speed switch,
Part number 90000541 should be used.
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L1 = High Speed
L2 = Medium Speed
L3 = Permanent Live
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Mechanical Installation
Mechanical installation should only be carried out
by a competent person. Fans are supplied ready for
installation. Care should be taken when removing
the fan from its packaging. Correct lifting
techniques / apparatus should be used where
necessary. Fans should be inspected for any
damage. If the fan is found to be damaged it should
be returned to the supplier immediately. Fans
should be installed to a sufficiently solid structure
giving adequate support. Fixings supplied with the
unit should be used. Alternatively, Airflow
Developments Rubber mount part number
90001294 (set of four) can be used to help protect
against mechanical noise transmission into the
mounting surface.
Units are mounted by using the 6mm clearance
holes provided in the extract duct connection box.
See fig A –B –C & D page 10.
Units can be mounted at any angle or position.
When mounting ensure there is no distortion to the
fan case.
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Mechanical Installation contd.
Air in
Air out
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