Marsh MAHLA Troubleshooting Manual

Troubleshooting Guide
Updated January 2025
MAHLA and MAHLAPS
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Please read all of the notes below.
General Notes
Whenever an enclosure is opened for fault finding, it should be initially isolated from mains
power and checked for water ingress or damage before restoring mains power for testing and
operation. Any electrical diagnosis should be undertaken by a suitably qualified person.
MAHLA and MAHLAPS
The only difference between these two alarm models is that the PS version has an air pressure
switch to monitor the running of the air compressor for the plant.
If you have the PS model with the pressure switch and you do not want to monitor the pressure
you can either:
Disconnect one or both wires between the pressure switch and the alarm board or move the
spade connector on the pressure switch from the Normal Position to the Disabled Position.
Ensure that if you disconnect wires from the board that
uninsulated ends are not left floating as this could cause
a short circuit and damage the product.
If you move the spade connector, a compressor
must not be connected to the switch by an
air-line as this will activate the alarm when the
compressor is started.
Marsh Industries Ltd. Addington Park Industrial Estate, Little Addington, Kettering,
Northamptonshire, NN14 4AS. Tel:01933 654582