Dx Cooling; Condensate Drain Pans; Winterizing Coils; Supply Fans - AAON H3 Series Installation Operation & Maintenance

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.

Condensate Drain Pans

Drain pans will have moisture present and
require periodic cleaning
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 must be done only by qualified
personnel.

Winterizing Coils

In some cases it may be necessary to
winterize water coils to prevent them from
freezing.
First completely drain the coils. There is a
drain located below the 'water in' connection
and a vent connection located above the
'water out' connection. Auxiliary drain
piping can also be added to exterior water
piping if yearly winterizing is necessary.
After the coil is drained, fill with an
antifreeze solution using a circulating pump.
Then thoroughly drain.
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Supply Fans

to prevent

E-Coated Coil Cleaning

Documented routine cleaning of e-coated
coils is required to maintain coating warranty
coverage for fin and tube and microchannel
coils. See the AAON E-Coated Coil
Maintenance Record sheet.
Surface loaded fibers or dirt must be
removed prior to water rinse to prevent
restriction of airflow. If unable to back wash
the side of the coil opposite of the coils
entering air side, then surface loaded fibers
or dirt must be removed with a vacuum
cleaner. If a vacuum cleaner is not available,
CAUTION
Blower wheels must be inspected for
excessive dust build up periodically
and cleaned if required. Excessive
dust build up on blower wheels may
cause an unbalanced state; leading to
vibration and/or component failure.
Damages due to excessive dust build
up will not be covered under factory
warranty.
WARNING
Electric shock hazard. Shut off all
electrical power to the unit to avoid
shock hazard or injury from rotating
parts.
WARNING
Electric shock hazard. Shut off all
electrical power to the unit to avoid
shock hazard or injury from rotating
parts.