Haier GE APPLIANCES AZ45E07D 5 Series Technical Service Manual page 48

As viewed from the front, the MUAM is
located on the left side and located on
the back side of the bulkhead. Some
models may have a replaceable filter. Most
properties will have their own maintenance
personel do this replacement.
When the Zoneline is first powered, the
MUAM cycles on and the damper assembly
door closes, then two variable speed fans
turn on. The fans run for approximately
30 seconds (speed will change) with the
door closed. The MUAM monitors the fans
running with door closed. After 30 seconds,
the damper door opens and the control is
able to detect a change in fan operation. The
control is able to detect the air resistance
when door is open and closed through
current draw. If the control does not see
a change, the damper door is considered
inoperative in either the open or closed
position and will set a Fault Code of 24
(replace the damper assembly). If the control
detects a bad fan condition, a Fault Code of
23 will be logged (replace the module). After
30 seconds, the compressor will cycle on
(if temperature and humidity requirements
have been met). If the control detects the
sealed system is not operating correctly,
Fault Code 23 will be set and the module
will need to be replaced. Located within
the MUAM control box are a microcontroller,
outdoor thermistor, sealed system thermistor
and humidity sensor. MUAM components
(except for damper assembly) are not
available separately requiring the module to
be replaced.
The module is secured with two screws and
tabbed into a base plate mounted to the base
pan. Some new zoning regulations require that
incoming air be conditioned.
If troubleshooting the Make-Up Air Module with
an amp probe, the amperage should be between
.75 and 1-amp, measured on the blue wire of the
Make-Up Air Module harness. This is dependent
upon the line voltage.
If for some reason the customer doesn't want
to use the MUAM and complains of air coming
through the Zoneline, a panel can be ordered
and installed (Part #: WP76X21320) to block the
outside opening.
Connections on the main control to
the MUAM are through J305 and J404
connectors located on the back of the control.
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