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CBX32MV SERIES
S
The outdoor unit should come on immediately and the
indoor blower should start between 30 − 60 seconds
later.
S
Check the airflow from a register to confirm that the
system is moving cooled air.
S
Set the thermostat 5ºF higher than the indoor
temperature. The indoor blower and outdoor unit
should cycle off.
CHECK ELECTRIC HEATER (IF USED)
S
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.
S
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. After a delay, 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 and after the
relay’s time-delay, the compressor and outdoor fan will
cycle 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. After a delay, 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. 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.
Maintenance
DEALER
WARNING
Electric shock hazard. Can cause injury
or death. Before attempting to perform
any service or maintenance, turn the
electrical power to unit OFF at disconnect
switch(es). Unit may have multiple power
supplies.
WARNING
Improper installation, adjustment, alteration, service or
maintenance can cause personal injury, loss of life, or
damage to property.
Installation and service must be performed by a licensed
professional installer (or equivalent) or a service agency.
Maintenance and service must be performed by a qualified
installer or service agency. At the beginning of each
cooling season, the system should be checked as follows:
Outdoor Unit
1. Outdoor unit fan motor is pre−lubricated and sealed.
No further lubrication is needed.
2. Visually inspect all connecting lines, joints and coils for
evidence of oil leaks.
3. Check all wiring for loose connections.
4. Check for correct voltage at unit (unit operating).
5. Check amp draw on outdoor fan motor.
Motor
Nameplate
:_________
Actual
:__________.
6. Inspect drain holes in coil compartment base and
clean if necessary.
NOTE - If insufficient cooling occurs, the unit should be
gauged and refrigerant charge should be checked.
Outdoor Coil
Clean and inspect outdoor coil (may be flushed with a
water hose). Ensure power is off before cleaning.
NOTE It may be necessary to flush the outdoor coil
more frequently if it is exposed to substances which are
corrosive or which block airflow across the coil (e.g., pet
urine, cottonwood seeds, fertilizers, fluids that may contain
high levels of corrosive chemicals such as salts)
