AAON RN Series, Installation Operation & Maintenance, Page: 63 / 136

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Electric Heating Operation
When a call for heating (G and W1, W2, etc.)
is made the supply blower 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 and
Heating 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.
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.
Chilled Water or Non-Compressorized
DX Cooling Operation
Controls for chilled water cooling coils and
non-compressorized DX coil are by others.
Maintenance
(See back of the manual for maintenance log)
At least once each year, a trained, qualified
service technician must check out the unit.
Fans, evaporator coils, and filters must be
inspected at least monthly.
Supply Fans
Lubrication
All original fan motors and bearings are
furnished with factory lubrication. Some
applications will require that bearings be re-
lubricated periodically. The schedule will
depend on the operating duty, temperature
variations or other severe atmospheric
conditions.
Re-lubricate bearings when at normal
operating temperatures, but not running.
Rotate the fan shaft by hand and add only
enough grease to purge the seals. DO NOT
OVERLUBRICATE.
Electric shock hazard. Shut off all
electrical power to the unit to avoid
shock hazard or injury from rotating
parts.
WARNING
Blower wheels and bands 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.
CAUTION