Instruction manual

Page 13 of 18Issue 1234507120-01
Check-out Procedures
NOTE: Refer to outdoor unit installation instructions for
system 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
ceiling 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
insulated?
• Have all cabinet openings and wiring been sealed?
• Is the indoor coil orifice metering device 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
• The indoor blower should come on.
CHECK COOLING OPERATION
• Set thermostat to force a call for cooling (approximately
5°F lower than the indoor ambient temperature ).
• The outdoor and indoor units should come on
immediately.
• Check the airflow from a register to confirm that the
system is moving cooled air.
• Set the thermostat 5°F higher than the indoor
temperature. The indoor blower and outdoor unit
should cycle off. Air handler should cycle off 45
seconds after the outdoor unit shuts off.
CHECK ELECTRIC HEATER (IF USED)
• Set thermostat to call for auxiliary heat (approximately
5°F above ambient temperature). The indoor blower
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)
When the thermostat calls for cooling, 24 volts is put on
the blower time-delay relay coil and then the indoor blower
relay energizes. The normally open contacts close,
causing the indoor blower motor to operate. 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
reversing valve remains energized as long as the
thermostat selector switch is in the COOL position.)
At the completion of the cooling demand the indoor blower
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 subbase, or they may also be
connected to a second stage on the subbase.
HEATING (HEAT PUMP)
When the thermostat calls for heating, 24 volts is put on
the blower time-delay relay coil. Then normally open
contacts close, causing the indoor blower motor to operate.
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. Circuit R and G
energizes the blower relay, starting the indoor blower motor.
If the room temperature should continue to fall, the circuit
between R and W1 is completed by the second-stage heat
room thermostat. Circuit R-W1 energizes a heat
sequencer. The completed circuit will energize
supplemental 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
subbase.
EMERGENCY HEAT (HEATING HEAT PUMP)
If the selector switch on the thermostat is set to the
emergency 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 subbase so that the electric
heat control 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 position.