AAON V3-E - Manual (Page 37)

37
Operation
Unit operations should be controlled with
thermostat or unit controller, never at the
main power supply, except for emergency or
complete shutdown of the unit.
Electric Heating Operation
When a call for heating (G and W1, W2,
etc.) is made the supply fan motors and
electric resistance heaters will energize.
Heating
is accomplished by passing
electrical current through a specified amount
of resistance heaters which will produce the
required heat.
On a fault condition the main limit located
in the supply air or the auxiliary limit
located downstream the supply blower will
remove power from all contactors.
Steam or Hot Water Preheating
Operation
Valve control for steam and hot water
heating coils are by others. Heating is
accomplished by passing steam or hot water
through the steam or hot water coil
assembly.
Chilled Water or Non-Compressorized
DX Cooling Operation
Valve controls for chilled water cooling coil
and non-compressorized DX coil are by
others.
Modulating Electric Preheat
Electric preheat is used to temper the
incoming outside air to the unit based on an
enable control signal and outside air
conditions. Electric preheat has a maximum
operation outside air temperature of 60°F
and a maximum preheat discharge air
temperature of 80°F.
Maintenance
(See back of the manual for maintenance
log.)
At least once each year, a qualified service
technician should check out the unit. Supply
fans, evaporator coils and air filters should
be inspected monthly.
Periodically during operation, it is necessary
to perform routine service checks on the
performance of the unit. This includes
checking of the air flow, the air filters,
condenser water flow and refrigerant charge.
See Startup section for information on air
flow adjustment and refrigerant charge
adjustment.
DX Cooling
Set unit controls to cooling mode of
operation with supply fans on. Check the
fans
for correct operating direction,
amperage and voltage. Check compressor
operation, rotation, amperage and voltage to
the unit nameplate (check the amperage on
the load side of the compressor contactor).
Condensate Drain Pans
Drain pans will have moisture present and
require
periodic cleaning to prevent
microbial growth. Cleaning of the drain pans
will also prevent any possible plugging of
the drain lines and overflow of the pan itself.
Cleaning of the drain pans and inside of the
unit should be done only by qualified
personnel.
Improper installation, adjustment,
alteration, service or maintenance
can
cause property damage,
personal injury or loss of life.
Installation and service must be
performed by a qualified installer. A
copy of this IOM should be kept with
the unit.
WARNING