Zehnder Rittling Centair CMEV.4e User manual

Centair CMEV.4e / CMEV.4eHT
Central Mechanical Extract Ventilation
Insta ation Instructions
CMEV.4e / CMEV.4eHT

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Page
1.0 Genera Description / Physica Specification ........................... 3
2.0 Insta ation Instructions .............................................................. 4
2.1 General Preparation ...................................................................... 4
2.2 Positioning / Application ................................................................ 5
2.3 Mounting ....................................................................................... 5
2.4 Ducting Guidelines ....................................................................... 6
2.5 Electrical ....................................................................................... 7
3.0 On-Site Commissioning ............................................................. 11
4.0 Performance Graphs ................................................................... 13
5.0 Guarantee ..................................................................................... 14
Contents

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1.0 Genera Description / Physica Specification
1.1 Overview
1.1.1 The CMEV.4e range is a ventilation system designed to provide improved indoor air quality in dwellings. As
a whole house system, the unit constantly extracts air from rooms generating moisture and odours in dwellings
(Kitchens, Wet Rooms, Utility Rooms and WC’s).
1.1.2 A boost speed facility is provided to increase the ventilation rate during peak times, providing a comfortable
indoor environment. A boost switch (not supplied) should be wired to provide this operation (see section - 2.5
Electrical).
1.1.3 These products feature on PCDB and part of the process requires the nstallation Checklist for MEV
products to be completed and submitted to building control, available at www.ncm-pcdb.org.uk, along with
all other relevant paperwork.
1.1.4 These instructions cover the following units –
• CMEV.4e – Low Energy Version - 2 or 3 speed depending on wiring & sensor
configuration (see page 8).
• CMEV.4eHT – Low Energy with Greenwood HumidiSMA TTM and Greenwood
TimerSMA TTM Technology - 2 or 3 speed depending on wiring &
sensor configuration (see page 8).
1.1.5 Packaging Includes – 1 x CMEV.4e or CMEV.4eHT Unit
2 x Spigot Blanking Caps
Quick User / Quick nstaller Guide
1.1.6 Ancillary tems Required • 125mm Ducting (rectangular ducting 204 x 60mm can be used,
where appropriate)
• 125mm Grilles
• ZGS2 Hardwired switch providing switching between low and high (option)
• ZGS1 Hardwired switch providing switching between low, medium and
high (option).
1.1.7 Warning: This appliance can be used by children aged from 8 years and above and persons with reduced
physical, sensory or mental capabilities or lack of experience and knowledge if they have been given
supervision or instruction concerning use of the appliance in safe way and understand the hazards involved.
Children shall not play with the appliance. Cleaning and user maintenance shall not be made by children without
supervision.
1.1.8 Where an open-flued oil or gas-fuelled appliance is installed, precautions must be taken to avoid a back-flow of
gases into the room.
1.1.9 The design, material specification and installation must only be carried out by “competent persons”. Electrical
installation must be carried out by a qualified Electrician.
1.1.10 f the supply cord is damaged, it must be replaced by a special cord / assembly available from the manufacturer
or its service agent. The replacement must be carried out by a qualified electrician in accordance with EE or
local regulations.
1.1.11 Observe appropriate safety precautions if working on steps or ladders. Wear eye protection when breaking out
wall or window materials, etc.
1.1.12 To disassemble the unit, disconnect from mains supply and use a screwdriver to segregate the electronic
components and motor from the plastic housing. Dispose items in accordance with WEEE.

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370
380
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1.1.13 WEEE Statement
This product may not be treated as household waste. nstead it should be handed to
an appropriate collection point for the recycling of electrical and electronic equipment.
For more detailed information about the recycling of this product, please
contact your local council office or your household waste disposal service.
1.2 Physical Specifications
2.0 Installation Instructions
2.1 General Preparation
2.1.1 The CMEV.4e range of units are supplied with 5 x 125mm ducting spigots for connection of ducts to the unit for
installation and 2 x blanking caps to close or block off unused spigots. One inlet spigot is located under the
base of the unit and is supplied blanked off. For installations requiring fifth inlet port, proceed to cut out the
spigot blank and connect duct. (See Figure 1).
2.1.2 125mm duct should be used to provide the best performance levels required for compliance with building
regulations. The CMEV.4e range has been tested with both 125mm and 100mm round ducting. Note;
Reducing ductwork to 100mm will increase system resistance and affect overall specific fan power ratings.
Technical Services can be contacted on [phone] should you have any questions in respect of this.
2.1.3 nstallation of the unit should be in accordance with the current editions of Building Regulations and
BS7671: EE Wiring Regulations.
2.1.4 The design, material specification and installation must only be carried out by ‘competent persons’. Electrical
installation must be carried out by a qualified Electrician.
2.1.5 Ducting must be installed as per the Domestic Ventilation Compliance Guide 2010 and insulation must be
used if located outside of the thermal envelope.
Front View Side View

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Carefu y cut out spigot cap with
a b aded too
Discard waste materia
responsib y
Connect ductwork as
appropriate
Cei ing Mounted in cupboard Wa Mounted Loft Mounted on p atform
2.2 Positioning / App ication
2.2.1 The unit can be installed in any plane and should be sited in a service cupboard, on a wall or ceiling or in a
loft space (See Figure 2). t is not advisable to install the unit directly above a bedroom or living room ceiling, or
in an area that is part of a living area or bedroom.
2.2.2 The unit must be securely mounted at each corner using either single or slotted fixing holes provided
(See Figure 3).
Note; Fixing points have been designed to hold screws, for ease, when positioning/mounting the product to a
surface.
2.2.3 Figure 1 - Optional Fifth Spigot
2.2.3 Figure 2 - Mounting Orientations
2.3 Mounting
2.3.1 Determine the duct inlet and exhaust configuration and the best orientation for the unit for this installation, also
taking account of the access to the electrical services, and whether the fifth inlet port (supplied capped off)
located on the unit base may assist with the dwelling/room layout.
2.3.2 Ensure there is adequate access for installation and eventual replacement (See Figure 4).
2.3.3 Once the fixing position and location have been determined, fit the blanking caps onto any unused spigots.
2.3.4 Securely mount the unit to the fixing surface with four screws (not supplied) and proceed to connect ducts.
Note; The fan can be fitted using one corner fixing and aligned if necessary using the slotted holes
provided. (See Figure 3).

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2.3.5
2.4 Ducting Guide ines
2.4.1 Please refer to design drawings for proposed ducting layout.
2.4.2 5 x 125mm nominal diameter spigots are provided for connection to ducting. Ductwork should be securely
connected to spigots. Failure to do this will cause unnecessary air leakage and impair performance.
2.4.3 Where ducts are exposed in unheated areas, such as roof spaces, they must be insulated with at least 25mm of
insulation that has a thermal conductivity of ≤0.04w(m.K)
2.4.4 f applicable, Fire dampers MUST BE FITTED in accordance with Part B of the Building Regulations.
2.4.5 igid Ducting
• nstall using the least number of fittings to minimise resistance to air flow.
• Where possible, final connection to grilles and unit should be made with a flexible connection.
• Mechanically fix ducts using metal jubilee clips or heavy duty plastic cable ties and appropriate
non-hardening sealant for air tightness.
WA NING: Do not use screws for connection and ensure jubilee clips are not over tightened.
2.4.6 Flexible Ducting
• Ensure ducting lengths are kept to a minimum and ducting is pulled taut so that it is smooth and straight.
Where bends are necessary and where ducting is run in restricted areas, ensure the ducting is not crushed.
• Mechanically fix ducts using metal jubilee clips or heavy duty plastic cable ties and tape seal for air
tightness.
WA NING: Should be in accordance with Building egulations.
2.4.7 The exhaust port of the unit must terminate to external air and be protected by a suitable wall or roof terminal.
• Roof terminal to have a minimum equivalent free area of 10,000mm2.
2.4.8 Ensure unused spigots are capped off using the blanking caps provided.
Figure 3 - Location of Fixing Ho es Figure 4 - Access for Maintenance
Footprint of
CMEV.4e / CMEV.4eHT

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2.5 E ectrica
2.5.1 WA NING: The appliance MUST be earthed. All wiring must conform to BS7671: IEE Wiring egulations.
2.5.2 WA NING: The CMEV.4e / CMEV.4eHT units must be isolated from the mains supply before removing
the fan motor assembly.
2.5.3 The installation must be carried out by a qualified Electrician.
2.5.4 When supplied from a 6 amp lighting circuit no local fuse is required. f electricity is not supplied via the
lighting circuit, a localised 3 amp fuse must be used (see wiring diagrams).
2.5.5 The CMEV.4e / CMEV.4eHT units are supplied with a pre-wired mains flexible cord – PVC sheathed, 5-core
green/yellow, blue, brown, black & grey & 0.75mm2.
‘If the supply cord is damaged, it must be replaced by a special cord/assembly available from the
manufacturer or its service agent. The replacement must be carried out by a qualified Electrician in
accordance with IEE or local regulations’.
2.5.6 Depending on required wiring (see diagrams), a triple-pole or a double-pole switch having a minimum contact
separation of 3.0mm must be used to provide isolation for the unit.
2.5.7 The recommended switches / sensors for use with either models are:
• For CMEV.4e, wire using either switch-live (lighting circuit) with/without external sensor or via a Zehnder
ZGS2 2-position switch with an external sensor (see below for function details).
• For CMEV.4eHT, wire using either switch-live (lighting circuit), via a Zehnder ZGS2 2-position switch
with/without an external sensor or via a Zehnder ZGS1 3-position switch (see below for function details).
(See Wiring Diagrams on page 8).
2.5.8 The controllers must not be mounted in a bathroom or above/closer than 1 metre to a cooker where it could be
affected by excessive heat or moisture.
ZGS2 Remote Function
Switch Positions
Trick e (I) Fan running at trick e speed
Boost (II) Fan running at med/boost speed
II
I
II
I
ZGS1 Remote Function
Switch Positions
Trick e (Centre position) Fan running at trick e speed
Medium (I) Fan running at medium speed
Boost (II) Fan running at boost speed
CMEV.4e / CMEV.4eHT
CMEV.4eHT only
ZGS2
ZGS1

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2.6 Wiring Diagrams Key: Earth = Green / Yellow
Neutral = Blue
Brown = Permanent Live
Black = Medium speed
2.6.1 Two speed control via light switch (CMEV.4e / CMEV.4eHT) Grey = High speed
2.6.2 Two speed control via ZGS2 switch (CMEV.4eHT only)
2.6.3 Three speed control via light switch for trickle & boost speeds and medium speed activation via remote sensor
(CMEV.4e only)
2.6.4 Three speed control via ZGS2 switch for trickle & boost speeds and medium speed activation via remote sensor
(CMEV.4e / CMEV.4eHT)
2.6.5 Three speed control via ZGS1 switch (CMEV.4eHT only)

Ste 1 Ste 3Ste 2
‘LOCKED’ ‘UNLOCKED’
Line Indicator
(1)
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2.7 BMS Connectivity - CMEV.4eHT Only
2.7.1 The CMEV.4eHT unit can be connected to a BMS system that can provide a variable 0-10 Volt output that will be
used to control the fan operating speed, as shown within table 1.1 below:
2.7.2 emoval of Fan Motor Assembly (See Figure 5)
WA NING: The CMEV.4eHT unit must be isolated from the mains supply before removing the fan motor
assembly.
1) emove external locking screw (1).
CAUTION; Fan motor assembly is free to move after the next operation – in ceiling installations
please ensure the fan is manually supported during the following steps.
2) Rotate anti-clockwise, noting ‘L NE ND CATOR’ moving from the ‘LOCKED’ to ‘UNLOCKED’ position
(See Figure 5a).
3) Fan motor assembly can now be lowered / lifted out of main fan housing.
2.7.3 Figure 5 – Removal of Fan Motor
Figure 5a – ‘LOCK’ & ‘UNLOCK’ Positions
Voltage S eed Control
0V – 3.2V Trick e
3.3V – 6.4V Medium
6.5V – 10V Boost
Tab e 1.1

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2.7.4 Wiring of the BMS to the CMEV.4eHT (See Figure 6)
1) Remove the three screws connecting the lid.
2) Carefully remove the lid to expose the PCB.
3) Carefully pierce through the ‘closed’ top hole within the lids cable grommet and pass through the BMS
cable (not provided).
4) Remove the internal cable clamp in readiness for the BMS wiring.
5) Using a 5 or 6 core cable, sized between 0.326mm2- 0.205mm2, insert wires into the BMS terminal
block on the PCB (as per table 1.2 below). Pin 2 is a volt free contact for additional sensors.
6) Secure the cable within the internal cable clamp provided.
7) Carefully realign the lid to the ‘pot controls’ and respective screw connections and secure with the three
connecting screws.
2.7.5 Figure 6 – Connecting BMS Wiring
Ste 1 Ste 3Ste 2
Ste 4
Ste 6
Ste 5
Ste 7
BMS
Cab e
Pin FunctionConection to External Circuit
1 Speed 0-10V positive input from PSU (ana ogue input)
2Boost Vo t freecontact for additiona sensors to Boost
3Ground 0V connection to PSU and Boost signa
4N/C Oso ated re ay norma y c osed contact
5N/O Oso ated re ay norma y open contact
6Common Oso ated re ay common contact
Tab e 1.2

Ste 1Ste 3
Ste 2
‘LOCKED’ ‘UNLOCKED’
Line Indicator
(1)
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2.7.6 Fan Motor Assembly eplacement (See Figure 7)
1) Realign the fan motor assembly ‘L NE ND CATOR’ with the ‘UNLOCKED’ symbol on main fan housing.
2) Ensure fan motor assembly has a positive fit, and push firmly into main fan housing. Rotate fan motor
assembly until it stops. The ‘L NE ND CATOR’ should now be in line with the ‘LOCKED’ symbol
(See Figure 7a).
3) Replace external locking screw (1).
4) Turn on mains supply and confirm correct operation.
2.7.7 Figure 7 – Replacement of Fan Motor
Figure 7a – ‘LOCK’ & ‘UNLOCK’ Positions
3.0 On Site Commissioning
3.1 Overview
3.1.1 This section covers set up, configuration of the unit on installation and altering pre-set factory settings. Dependant
on which model has been installed the following set up and configuration will apply.
3.1.2 CMEV.4eHT Only – Greenwood TimerSMA TTM and Greenwood HumidiSMA TTM
The CMEV.4eHT features a fully automatic integral timer function and humidity function which monitors the
homeowners’ environment. Neither of these functions require set-up.
3.1.3 Once the wiring connections have been checked, switch the mains supply on and check that the system is
operating correctly, as per installed wiring / switch / sensor control configurations (see respective per wiring
diagram).
3.1.4 Refer to performance graph for relevant model for airflow characteristics (See section 4.0).

Trick e Speed Factory
set to setting 2
Trick e Speed Factory
set to setting 3
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3.1.5 Use ‘turn pots’ to achieve the desired motor speed at both speeds. Medium speed represents the mid speed
between the two settings. For example, if the trickle speed ‘pot’ is set to 20% of full motor speed and the boost
speed ‘pot’ is set at 60%, Medium speed will automatically be 40%.
3.1.6 Commissioning – Factory Settings
Factory settings suitable for two bedroom apartments up to 100m2floor area, with a Kitchen plus 2 Wet Rooms
(such as Bathroom, Utility Room, Shower Room, Ensuite, WC).
3.1.7 Commissioning – Fine Tuning
Minor adjustments may be required depending on overall ductwork length.
Fine-tuning of the motor speeds can be achieved by using the ‘turn pots’ on the fan casing to ensure
optimum efficiency (See Figure 8). Record airflow rates for room extract valves and also the ‘pot’ settings
for trickle and boost speeds on the front page of this installer guide.
Figure 8 - ‘Speed Pot’ Setting Adjustment Panel
Note; Fan performance can be adjusted between these set points for further fine tuning, as the motor is 100%
variable in range.
3.1.8 Valve Set-up
Performance levels to be verified at the extract valves using an appropriate method such as a rotating vane
anemometer and air cone kit.
To adjust valves:
• Set the fan speed approximately to achieve the desired extract high flow rate.
• Close all windows and doors, including the rooms in which measurements are being carried out.
• The index terminal (the one furthest away) should be set to fully open.
• All other terminals are adjusted to achieve the required flow rate.
• f the index terminal has to be closed to achieve the correct flow rates, then reduce the fan speed and
balance the terminals.
• Switch the unit to low speed to achieve the desired extract low flow rate. t should not be necessary to
adjust the extract valves further.

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4.0 Performance Graphs
4.0.1 Airflow Characteristics for CMEV.4e / CMEV.4eHT Models

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5.0 The Guarantee Period
5.1 This product has a 2 Year Guarantee as standard with the option to extend to a 6 Year Guarantee,
subject to registration. Terms and conditions apply.
5.1.1 This does not affect your statutory rights.
5.1.2 Full details available on request from [phone] or www.greenwood.co.uk /
[email protected]

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All information is believed correct at time of going to press. E&OE.
All goods are sold according to Zehnder Group UK Ltd’s Standard Conditions of Sale which are available on
request. All dimensions referred to are in millimetres unless otherwise shown.
Zehnder Group UK Ltd reserves the right to change specifications and prices without prior notice.
© Copyright Zehnder Group UK Ltd 2021.
Zehnder Group UK Limited
Watchmoor Point, Camberley,
Surrey, GU15 3AD
Customer Services: [phone]
Technical Services: [phone]
Email: [email protected]
Web: www.greenwood.co.uk
05.10.874 Issue 7 May 2021