Operation, Thermostat operation, Compressor – AAON CB-060 User Manual

Page 25: Variable capacity compressor controller, Warning

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25

Operation


Unit operations should be controlled with
thermostat, or unit controller, never at the
main power supply, except for emergency,
servicing, or complete shutdown of the unit.

Thermostat Operation
Heating
Thermostat system switch - "Heat"
Thermostat fan switch - "Auto" or "On"
Thermostat temperature set to desired point.

Cooling
Thermostat system switch - "Cool"
Thermostat fan switch - "Auto" or "On"
Thermostat temperature set to desired point.

Air Circulation
Thermostat system switch - "Off"
Thermostat fan switch - "Auto" or "On"
No change of the thermostat temperature.
With these settings, the air handler’s supply
fan will run continuously but the supply air
will not be heated, cooled, or dehumidified.

System Off
Thermostat system switch - "Off"
Thermostat fan switch - "Auto"
No change of the thermostat temperature.
With these settings, the system is shut down,
with the exception of the control system
power (24 VAC), and the crankcase heaters
(about 60 watts/compressor).

Night and Weekend Unoccupied Operation
To reduce the operating time of the unit
when the space is unoccupied, such as nights
and weekends, it is recommended that the
temperature setting be raised about 5°F
while unoccupied during the cooling season
and lowered about 10°F during the heating
season.


Compressor
The compressors must be off for a minimum
of 5 minutes and on for a minimum of 5
minutes. Short cycling of the compressors
can causes undue stress and wear.


















Variable

Capacity

Compressor

Controller
Units with variable capacity scroll
compressors may include variable capacity
compressor controller. The following is an
explanation of the terminals and
troubleshooting of the alert flash codes on
the controller. For more information on the
compressor controller, see Emerson Climate
Bulletin AE8-1328.













COMPRESSOR CYCLING

5 MINUTE MINIMUM OFF TIME

To

prevent

motor

overheating

compressors must cycle off for a
minimum of 5 minutes.

5 MINUTE MINIMUM ON TIME

To maintain the proper oil level
compressors must cycle on for a
minimum of 5 minutes.

The cycle rate must not exceed 6
starts per hour.


WARNING

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