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Check-out Procedures
NOTE – Refer to outdoor unit installation instructions for sys-
tem start-up instructions and refrigerant charging instructions.
PRE-START-UP CHECKS
• Is the air handler properly and securely installed?
• If horizontally configured, is the unit sloped up to 5/8
inch toward drain lines?
• Will the unit be accessible for servicing?
• Has an auxiliary pan been provided under the unit with
separate drain for units installed above a finished ceil-
ing or in any installation where condensate overflow
could cause damage?
• Have ALL unused drain pan ports been properly
plugged?
• Has the condensate line been properly sized, run,
trapped, pitched, and tested?
• Is the duct system correctly sized, run, sealed, and in-
sulated?
• Have all cabinet openings and wiring been sealed?
• Is the indoor coil factory-installed TXV properly sized for
the outdoor unit being used?
• Have all unused parts and packaging been disposed
of?
• Is the filter clean, in place, and of adequate size?
• Is the wiring neat, correct, and in accordance with the
wiring diagram?
• Is the unit properly grounded and protected (fused)?
• Is the thermostat correctly wired and in a good location?
• Are all access panels in place and secure?
CHECK BLOWER OPERATION
• Set thermostat to FAN ON.
• The indoor blower should come on.
CHECK COOLING OPERATION
• Set thermostat to force a call for cooling (approximately
5ºF lower than the indoor ambient temperature).
• The outdoor unit should come on immediately and the
indoor blower should start between 30 - 60 seconds lat-
er.
• Check the air flow from a register to confirm that the
system is moving cooled air.
• Set the thermostat 5ºF higher than the indoor tempera-
ture. The indoor blower and outdoor unit should cycle
off.
CHECK ELECTRIC HEAT (IF USED)
• Set thermostat to call for auxiliary heat (approximate-
ly 5°F above ambient temperature). The indoor blow-
er and auxiliary heat should come on together. Allow a
minimum of 3 minutes for all sequencers to cycle on.
• Set the thermostat so that it does not call for heat. Allow
up to 5 minutes for all sequencers to cycle off.
Operation
Cooling (Cooling Only or Heat Pump)
On all models, the 24 volt line will go directly to the termi-
nal board from the transformer. The normally open con-
tacts close, causing the indoor blower motor to operate;
depending on the indoor blower motor, there may be a
delay. The circuit between R and Y is completed, closing
the circuit to the contactor in the outdoor unit, starting the
compressor and outdoor fan motor.
On heat pumps, circuit R and O energizes the reversing
valve, switching the valve to the cooling position. (The re-
versing valve remains energized as long as the thermo-
stat selector switch is in the COOL position.)
At the completion of the cooling demand, the indoor blow-
er and outdoor unit should cycle off. Air handler should
cycle off 45 seconds after the outdoor unit shuts off.
Heating (Electric Heat Only)
When the thermostat calls for heat, the circuit between R
and W is completed, and the heat sequencer is energized.
A time delay follows before the heating elements and the
indoor blower motor come on. Units with a second heat
sequencer can be connected with the first sequencer to W
on the thermostat sub-base, or they may also be connect-
ed to a second stage on the sub-base.
Heating (Heat Pump)
On all models, the 24 volt line will go directly to the termi-
nal board from the transformer. The normally open con-
tacts close, causing the indoor blower motor to operate;
depending on the indoor blower motor, there may be a
delay. The circuit between R and Y is completed, closing
the circuit to the contactor in the outdoor unit, starting the
compressor and outdoor fan motor.
If the room temperature continues to decrease, the cir-
cuit between R and W1 is completed by the second-stage
heat room thermostat. Circuit R-W1 energizes a heat se-
quencer. The completed circuit will energize supplemen-
tal electric heat (if applicable). Units with a second heat
sequencer can be connected with the first sequencer to
W1 on the thermostat. They may also be connected to
a second heating stage W2 on the thermostat sub-base.
Emergency Heat (Heating Heat Pump)
If the selector switch on the thermostat is set to the emer-
gency heat position, the heat pump will be locked out of
the heating circuit, and all heating will be electric heat (if
applicable). A jumper should be placed between W2 and E
on the thermostat sub-base so that the electric heat con-
trol will transfer to the first-stage heat on the thermostat.
This will allow the indoor blower to cycle on and off with
the electric heat when the fan switch is in the AUTO po-
sition.
Page 18
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