Friedrich MRM09Y1J, Service & Parts Manual

Page: 109 / 135

109 PB
Possible Causes Discriminating Method (Air conditioner
Status) Troubleshooting
Flow volume of valve is insufficient The pressure of valves is much lower than
that stated in the specification Open the valve completely
Malfunction of horizontal louver Horizontal louver can’t swing Refer to point 3 of maintenance method for
details
Malfunction of the IDU fan motor The IDU fan motor can’t operate Refer to troubleshooting for H6 for mainte -
nance method in details
Malfunction of the ODU fan motor The ODU fan motor can't operate Refer to point 4 of maintenance method for
details
Malfunction of compressor Compressor can't operate Refer to point 5 of maintenance method for
details
Horizontal Louver Will Not Swing
Wrong wire connection, or poor connection Check the wiring status according to circuit
diagram
Connect wires according to wiring diagram
to make sure all wiring terminals are con
-
nected firmly
Stepping motor is damaged Stepping motor can't operate Repair or replace stepping motor
Main board is damaged Others are all normal, while horizontal
louver can't operate Replace the main board with the same
model
ODU Fan Moto Can’t Operate
Wrong wire connection, or poor connection Check the wiring status according to circuit
diagram
"Connect wires according to wiring dia -
gram to
make sure all wiring terminals are con -
nected firmly"
Capacity of the ODU fan motor is damaged "Measure the capacity of fan capacitor with
an universal meter and find that the capac
-
ity is out of the deviation range indicated on
the nameplate of
fan capacitor."
Replace the capacity of fan
"Power voltage is a little low or
high"
"Use universal meter to measure the
power supply
voltage. The voltage is a little high or low"
Suggest to equip with voltage regulator
Motor of outdoor unit is damaged "When unit is on, cooling/heating perfor -
mance is bad and ODU compressor gener -
ates a lot of
noise and heat."
Change compressor oil and refrigerant. If
no better, replace the compressor with a
new one
Compressor Can’t operate
Wrong wire connection, or poor connection Check the wiring status according to circuit
diagram
"Connect wires according to wiring dia -
gram to make sure all wiring terminals are
connected
firmly"
TROUBLESHOOTING
Troubleshooting for normal Malfunction