AAON V3-E - Manual (Page 18)

18
If power to the unit must be off for more
than an hour, turn the thermostat system
switch to "OFF", or turn the unit off at the
control panel, and leave the unit off until the
main power switch has been turned on again
for at least 24 hours for units with
compressor crankcase heaters. This will give
the crankcase heater time to clear any liquid
accumulation out of the compressor before it
is started.
Always control the unit from the thermostat,
or control panel, never at the main power
supply, except for emergency or complete
shutdown of the unit.
During the cooling season, if the air flow is
reduced due to dirty air filters or any other
reason, the cooling coils can get too cold
which will cause excessive liquid to return
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
shortened 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 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.
Wiring Diagrams
Unit specific wiring diagrams are laminated
and affixed inside the controls compartment
door.
Condensate Drain Pans
Units require field installed drain p-traps and
lines to be connected to the condensate drain
pans of the unit. The lines 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.
Installation
AAON equipment has been designed for
quick and easy installation. Startup and
service must be performed by Factory
Trained Service Technician.
Unit should not be operated without a
p-trap. Failure to install a p-trap may
result in overflow of condensate
water.
CAUTION
CRANKCASE HEATER
OPERATION
Some units are equipped with
compressor
crankcase heaters,
which should be energized at least
24 hours prior to cooling operation, to
clear any liquid refrigerant from the
compressors.
CAUTION
Emergency drain pan is
recommended for all applications
where a risk of water damage to
surrounding structure or furnishings.
Refer to local codes.
CAUTION