AAON M2-036 - Manual (Page 29)

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to the compressor. As the liquid
concentration builds up, oil is washed out of
the compressor, leaving it starved for
lubrication.
The compressor life will be seriously
shorted by reduced lubrication and the
pumping of excessive amounts of liquid oil
and refrigerant.
Note: Low Ambient Operation
Air-cooled DX units without a low ambient
option, such as condenser fan cycling, ECM
driven condenser fans or the 0°F low
ambient option, will not operate in the
cooling mode of operation properly when
the outdoor temperature is below 55°F. Low
ambient and/or economizer options are
recommended if cooling operation below
55°F is expected.
Gas or Electric Heating
The unit is designed to heat a given amount
of air while operating. If this amount of air
is greatly reduced, approximately 1/3 during
the heating season, the gas heat exchanger or
electric heating coil may overheat, and may
cut the burner or heater off entirely by action
of the safety high temperature limit devices
which are factory mounted at the heat
exchanger and supply fan areas.
Airflow should be adjusted after installation
to obtain an air temperature rise within the
range specified on the unit rating plate at the
required external static pressure.
Should overheating occur with a gas heat
exchanger, or the gas supply fail to shut off,
shut off the manual gas valve to the furnace
before shutting off the electrical supply.
Prolonged overheating of the heat exchanger
will shorten its life.
If unit has not been selected as a 100%
outside air unit (make up air unit) the return
air duct must be sealed to the unit and the
return air temperature must be maintained
between 55
°F and 80°F.
Wiring Diagrams
Unit specific wiring diagrams are laminated
and affixed inside the controls compartment
door.
Condensate Drain Pan
Unit requires drain traps to be connected to
the condensate drain pan of the unit.
For condensate drain lines, the line should
be the same pipe size or larger than the drain
connection, include a p-trap, and pitch
downward toward drain. An air break should
be used with long runs of condensate lines.
Unit should not be operated without a
p-trap. Failure to install a p-trap may
result in overflow of condensate
water.
CAUTION
An auxiliary / emergency drain pan is
recommended for all indoor
applications where there is a risk of
water damage to surrounding
structure or furnishings. Refer to local
codes.
CAUTION