Maritime Geothermal ATF-45, Installation And Service Manual

Page: 67 / 110

1-Jun-2018 Page 67 002000MAN-01
INDOOR FAN/BLOWER TROUBLESHOOTING
Fault Possible Cause Verification Recommended Action
Low indoor
airflow
Dirty air filter. Inspect. Replace.
Dirty air coil. Inspect. Clean.
Poor ductwork. Measure delta T between supply
and return ducts at the unit. In
heating mode, it should not be
above 30°F(17°C).
The ECM fan will provide proper
airflow up to 0.5 inH2o for 1/2HP
motors and 0.7 inH2o for 1HP
motors. The ductwork is poorly
designed or greatly undersized if
the fan motor cannot provide the
required airflow.
Airflow selected is too low. Check airflow settings on Indoor Fan
page of the PC APP.
Select a higher setting.
Airflow reduction is ena-
bled.
AR1 and AR2 are connected with a
dry contact or jumper.
Airflow reduction may not be fea-
sible with lower airflow selections.
Increase settings until unit oper-
ates properly.
Indoor fan not
operating at cor-
rect speeds.
Wrong model size
selected.
Verify that the model size is correct
on the Configuration Page of the PC
APP.
Select the correct model size.
Indoor fan not
operating or op-
erating intermit-
tently
Fan control signal harness
and/or fan power harness
is loose.
Verify that the connector is properly
inserted into the fan motor. Gently
tug on each wire to verify it is
properly inserted into the connector.
Repair any loose connections.
Control board not config-
ured properly.
Verify that the model series is cor-
rect on the Configuration Page of
the PC APP.
Correct the configuration. If the
wrong series is selected there
may be not be any fan output.
Faulty fan power harness
or faulty motor.
Insert the tips of the voltmeter
probes into the back of the connect-
or at the fan to measure the voltage
across the red and black wires.
Value should be ~230VAC.
Replace power harness if
230VAC is not present, replace
motor if 230VAC is present.
Faulty control board out-
puts.
Note: cycle the power
once to see if the fan
begins operating
properly first.
Create a call for the fan from the
thermostat (24VAC on G terminal in
heat pump).
On the ECM Fan connector on the
left side of the control board:
1) verify that there is 12 to 20VDC
between pin G (grey wire) and
pin C (white wire).
2) Verify that there is 2 to 6VDC
between pin P (dark green wire)
and pin C (white wire)
If there is no voltage present on
either of the pins (G and P) re-
place the control board.
Ensure control board model se-
ries is correct, see above.
Faulty control signal har-
ness or faulty motor head.
Create a call for the fan from the
thermostat (24VAC on G terminal in
heat pump).
On the ECM Fan connector at the
fan motor:
1) verify that there is 12 to 20VDC
between pin G (grey wire) and
pin C (white wire).
2) Verify that there is 2 to 6VDC
between pin P (dark green wire)
and pin C (white wire)
If proper signal isn’t present, re-
place the fan control signal har-
ness. If proper signal is present,
replace fan motor.