Sequence Of Operation; Cooling; Heating (Electric Heat Only); Heating (Heat Pump) - Rheem RHSL-HM1817AA Installation Instructions Manual

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IMPORTANT: DO NOT DOUBLE FILTER THE RETURN AIR DUCT SYSTEM. DO NOT
FILTER THE SUPPLY AIR DUCT SYSTEM.
WARNING
Do not operate the system without filters. A portion of the dust entrained in the
air may temporarily lodge in the duct runs and at the supply registers. Any cir-
culated dust particles could be heated and charred by contact with the air han-
dler elements. This residue could soil ceilings, walls, drapes, carpets and other
articles in the house.
Soot damage may occur with filters in place, when certain types of candles, oil
lamps or standing pilots are burned.

9.0 SEQUENCE OF OPERATION

9.1 COOLING (COOLING ONLY OR HEAT PUMP)
• When the thermostat "calls for cooling," the circuit between R and G is completed,
causing the blower relay (BR) to energize. The N.O. contacts will close, causing the
indoor blower motor (IBM) to operate. The circuit between R and Y is also completed:
This circuit closes the contactor (CC) in the outdoor unit starting the compressor
(COMP) and outdoor fan motor (OFM).

9.2 HEATING (ELECTRIC HEAT ONLY)

• When the thermostat "calls for heat," the circuit between R and W is completed, and
the heater sequencer (HR
blower motor (IBM) will come on. Units with a second heater sequencer (HR
connected with the first sequencer (HR
nected to a second stage W

9.3 HEATING (HEAT PUMP)

• When the thermostat "calls for heat," the circuits between R and B, R and Y and R
and G are completed. Circuit R and B energizes the reversing valve (RV) switching it
to the heating position (remains energized as long as selector switch is in "heat" posi-
tion). Circuit R and Y energizes the contactor (CC) starting the outdoor fan motor
(OFM) and compressor (COMP). Circuit R and G energizes the blower relay (BR)
starting the indoor blower motor (IBM).
• If the room temperature should continue to fall, circuit R and W
second-stage heat room thermostat. Circuit R-W
The completed circuit will energize supplemental electric heat. Units with a second
heater sequencer (HR ) can be connected with first sequencer (HR
2
mostat or connected to a third heating stage W
on the thermostat indicates when supplemental heat is being energized.

9.4 BLOWER TIME DELAY (HEATING OR COOLING)

• All models are equipped with a blower time delay (BTD) in lieu of a blower relay (BR)
(see wiring diagram). The blower will run for 30 seconds after the blower time delay
(BTD) is de-energized.

9.5 DEFROST (DEFROST HEAT CONTROL)

• For sequence of operation for defrost controls, see outdoor heat pump installation
instructions.
• Supplemental heat during defrost can be provided by connecting the purple (PU) pig-
tail in the outdoor unit to the W on the thermostat. This will complete the circuit
between R and W through a set of contacts in the defrost relay (DR) when the out-
door heat pump is in defrost. This circuit, if connected, will help prevent cold air from
being discharged from the indoor unit during defrost.
• For most economical operation, if cold air is not of concern during defrost, the purple
wire can be left disconnected. Supplemental heat will then come on only when called
for by second stage room thermostat.
) is energized. The heating elements (HE) and the indoor
1
) to W on the thermostat sub-base or con-
1
on the sub-base.
2
energizes a heat sequencer (HR
2
on the thermostat sub-base. A light
2
) can be
2
is completed by the
2
).
1
) to W on ther-
1 2