AAON HA-50 - Manual (Page 6)

6
NORMAL OPERATION
COOLING
Set the thermostat system switch to "COOL".
Set the thermostat fan switch to "AUTO" or "ON".
Set the thermostat temperature at the desired point.
HEATING
Set the thermostat system switch to "HEAT".
Set the thermostat fan switch to "AUTO" or "ON".
Set the thermostat temperature at the desired point.
AIR CIRCULATION
Set the thermostat system switch to "OFF".
Set the thermostat fan switch to "ON".
Do not change temperature setting.
With these settings, the air circulating blower will run
continuously but the air will not be heated or cooled.
SYSTEM OFF
Set the thermostat system switch to "OFF".
Set the thermostat fan switch to "AUTO".
Do not change temperature setting.
With these settings, the system is shut down, with the
exception of the control system power (24 volts), and the
crankcase heater of the compressor (about 60 watts).
DO NOT TURN OFF THE MAIN POWER SWITCH.
NIGHT AND VACANT WEEKEND OPERATION
If it is desired to reduce the operating time during the
night, and during periods when the space is unused,
it is recommended that the temperature setting be
raised about five degrees during these periods of the
cooling season, and lowered about ten degrees during
the heating season.
SEQUENCE OF OPERATIONS
I. GENERAL INFORMATION
A. COOLING
1. Packaged Units
When the thermostat calls for cooling from the space, 'Y1'
makes 'R' to 'CC1' through the LPS (low pressure switch),
HPS (high pressure switch) and optional GOT (guaran-
tee off timer).
On larger units 'CC3' is also made. If additional cooling
is required 'CC2' and 'CC4' are made through their
respective pressure switches and timers.
B. HEATING (Optional)
1. Electric
When the thermostat calls for heat 'W1' makes 'R' to the
heat relay. All N.O. contacts close, and all N.C. contacts
open. The heat relay makes 'R' to the first stage of
electric heat.
On a fault condition the main limit located in the supply
air or the auxiliary limit located in the supply air fan
housing will remove power from all contactors.
If additional heating is required a second set of elements
can be turned on by 'W2'.