Operating instructions

133
CIRCUIT 1:
Terminal 1 is black wire and is compressor circuit
Terminal 2 is white wire and is run circuit to compressor.
DO NOT TEST.
Terminal 3 is red wire and is start circuit to compressor. DO
NOT TEST.
Terminal 4 is white wire and is 115V common
Terminal 5 is brown wire and is fan capacitor circuit to fan
motor. DO NOT TEST.
Terminal 6 is black wire and is high fan circuit
Terminal 7 is red wire and is low fan circuit
Terminal 8 is violet wire and is 115V common
Terminal 9 is violet wire and is reversing valve circuit. This
circuit is energized in heat pump mode only.
NOTE: DO NOT use a volt meter to do these checks as it
will give erroneous readings.
CIRCUIT 2:
Terminal 1 is orange wire and is compressor circuit
Terminal 2 is gray wire and run circuit to compressor. DO
NOT TEST.
Terminal 3 is brown wire and is start circuit to compressor.
DO NOT TEST.
Terminal 4 is white wire and is 115V common
Terminal 5 is brown wire and is fan capacitor circuit to fan
motor. DO NOT TEST.
Terminal 6 is black wire and is high fan circuit.
Terminal 7 is red wire and is low fan circuit
Terminals 8 & 9 are open.
NOTE: The Circuit 2 AC power module board is the one that
is staged and will have a delay from the Circuit 1 system. Verify
that Circuit 2 should be operating before start of diagnosis.
NOTE: DO NOT use a volt meter to do these checks as it
will give erroneous readings.
7. FUSE
A 3-amp DC fuse is installed in the AC power module board to
protect the system from shorts or overload created by discon-
necting or reconnecting components when DC volts are to the
system.
One test is to remove the fuse and do a continuity test. No
continuity requires the fuse be replaced. Continuity means
the fuse is good. Another test can be done without remov-
ing the fuse. Use a DC volt meter to check between ground
or negative (–) DC to each side of fuse. If there is voltage
on each side, the fuse is good. If there is voltage on one
side only, the fuse is defective and requires replacement.
8. ELECTRIC HEATER ASSEMBLY
The electric heater assembly is an optional component for
most roof top air conditioners; however, it is standard
equipment for Model 620315. It is not used with any heat
pump unit.
To check the heater limit switch, check for continuity across
the limit switch terminals with the limit switch at ambient
temperature. If you have an open limit switch (no continu-
ity), replace it.
9. RELAY 9T91/120V)
The relay is used on basement air conditioner Model 39224
and basement heat pump Model 39424 ONLY.
The relay has five terminals. Two terminals are not identi-
fied; they are the coil terminals. When the coil is not ener-
gized (no power to the coil terminals), continuity should
exist between COM to NC and no continuity between COM
to NO.
When the coil is energized (power to the coil terminals),
continuity should exist between COM to NO and no conti-
nuity between COM to NC.
There are four relays used in Models 39224 and 39424.
Two are used in the reversing valve circuit and are desig-
nated as HR (heat relay) on the wiring diagram. Two are
used in the furnace blower circuit and are designated as FB
(furnace blower) on the wiring diagram.