Installation - Vent-Axia MVDC-MS H Installation And Wiring Instructions

See the dimensional details below for the mounting hole positions.
-Spigot diameters are 125mm
C. INSTALLATION
To reduce the system resistance in your duct system, and therefore lower the speed, power consumption and noise
of the fan, please follow these instructions:
• Keep the length of duct runs to a minimum, particularly the exhaust duct run.
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Use larger diameter ducting rather than smaller.
•
If you need to use flexible ducting, make sure that it is fully extended and not crushed, sagging or torn.
•
Try to minimise the use of dampers by having similar length duct runs to the inlets.
•
The bend radius, (measured to the inside of the bend), should be at least 1x the duct diameter. The larger,
the better.
• Avoid having any bends, filters or other obstructions within 250mm of the fan inlets and outlet.
1. Position the MULTIVENT, taking into consideration the position of the rooms to be ventilated, the exhaust
position, the drainage position and the electrical services. Ensure there is adequate access for installation
and maintenance. Securely mount the MULTIVENT through the mounting brackets on the casing using the
appropriate anti-vibration mounts, screws, washers, rubber bushes etc.
2. Ducting passing through an unheated space should be insulated.
The MVDC-MS can be connected to either Ø125mm or Ø100mm ducting. Remove the blanking caps to
connect Ø125mm ducting. To connect Ø100mm ducting, peel out the centre of the cap with a screwdriver as
indicated on the cap and leave the cap surround in position.
Please note that the exhaust duct must always be Ø125mm ducting.
D. WIRING
WARNING: THE MULTIVENT AND ANCILLARY CONTROL EQUIPMENT MUST BE ISOLATED
FROM THE POWER SUPPLY DURING THE INSTALLATION / OR MAINTENANCE.
THE MULTIVENT UNIT MUST BE EARTHED.
IMPORTANT:- Please ensure that the supply cable passes through the ferrite
Bead supplied, Use the cable tie supplied to retain ferrite in position.
A. MVDC-MS (437634A):
1. Remove the cover by undoing the four screws and lifting it away.
2. With the power off, connect a suitable mains power cable from a switched, fused spur to the power supply PCB.
Use the cable clamps and clip provided to secure the lead.
3. Ensure all connections are correct and that all terminal screws and cable clamps are securely fastened.
4. To enable the fan to switch to boost or purge speed when a light is turned on, connect the switched live
connection from the lighting circuit to one of the LS connections on the mother board.
5. The switched live output (230V) from any other switch or controller (such as a pullcord or push button switch,
humidistat or PIR detector) can be connected to the LS terminal instead of connecting to a lighting circuit.
6. Following these set-up instructions, switch the mains supply on and check the system is operating correctly.
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