Vent-Axia MVDC-MS H Installation And Wiring Instructions page 6

B. MVDC-MS H (443298):
1. Remove the cover by undoing the four screws and lifting it away.
2. With the power off and using a suitable mains power cable from a switched, fused spur connect the Live and
Neutral to the power supply Terminal block and connect the Earth to the power supply PCB.
Use the cable clamps provided to secure the lead.
3. Ensure all connections have are correct and that all terminal screws and cable clamps are securely fastened.
4. To enable the fan to switch to purge speed (maximum speed) connect the switched live connection to the
'Purge' LS connection on the mother board.
5. The output (230V) from the internal humidistat PCB is connected to the 'Boost' LS terminal.
6. Upon installation it is possible that the humidity controller will make the fan run continuously until it has
acclimatised to the environment. As part of the installation process it is important to set/adjust the humidity
sensitivity to the desired position. The controller is already factory set to switch on at about 70% R.H.
7. To Lower the set-point use the enclosed adjuster to turn the adjuster ANTICLOCKWISE. This makes the
controller More sensitive.
To Raise the set-point use the enclosed adjuster to turn the adjuster CLOCKWISE. This makes the controller
Less sensitive.
8. Following these set-up instructions, switch the mains supply on and check the system is operating correctly.
To allow the MVDC-MS H to switch from Normal to Boost speed using the LS Input:
1. Connect an isolated switched live connection to the LS connection on the power supply terminal block.
WARNING: THE SWITCHED LIVE CONNECTION TO THE LS CONNECTION MUST BE
ISOLATED, FOR EXAMPLE USING AN ISOLATOR RELAY CONTROLLER, VENT-AXIA PART
NUMBER 442030 OR SIMILAR.
MVDC-MS H (443298) CONNECTION DIAGRAM
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