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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
personnel 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 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.
(
Continued next page
)
