AAON WH Series Installation Operation & Maintenance - Maintenance
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Hot Gas Reheat Dehumidification
For Hot Gas Reheat Dehumidification,
switch 1, position 9 must be set to “OFF”.
The compressor is enabled at full capacity
“Y2” when dehumidification mode is
enabled. The supply fan low speed and
reheat valve “RH” 24VAC outputs are
enabled. If the unit is equipped with
waterside economizer, the Entering Water
Temperature setpoint will be ignored, and
freeze protection will be monitored.
On/Off Waterside Economizer (WSE)
Coil Operation
As the entering water temperature drops
below the Entering Water Temperature
setpoint, if the compressor is enabled, the
call for the compressor will be removed
once the minimum on time has been
satisfied, and the WSE 24VAC output will
be enabled, sending the cold loop water
through the air coil to utilize “free cooling”.
Once the entering water temperature rises
above the Entering Water Temperature
setpoint plus the deadband, the WSE will be
disabled, and compressor cooling will be
utilized.
The WSE will act as the unit’s first stage of
cooling. If the cooling call has not been
satisfied within 10 minutes of operation, the
WSE valve will disable. Following a delay,
the unit will resume normal compressor
cooling operation until the cooling input is
removed. When this happens, the Pioneer
Silver controller green LED will flash,
signifying the WSE was unable to meet the
cooling call.
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 performance of the
unit. This includes checking of the air flow,
the air filters, and condenser water flow.
See Startup section for information on air
flow 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).
Check for 24v signal across the reversing
valve terminals.
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.