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Blinking
LED
Diagnosis of malfunction Cause Check point
LD1
Reversed phase Phases A
1
, A
2
, and A
3
are con-
nected improperly.
Check the power supply connection.
LD2
Open phase ● Phase A
2
is open.
● Contact of protector, such as
thermal switch, opened when
power was turned on.
● Check the power supply.
● Check each protector.
LD3
Outdoor coil thermistor is
abnormal. (Open circuit or short
circuit)
● Outdoor coil thermistor is
broken.
● Thermistor was connected
incorrectly.
● Measure the resistance of the thermistor.
● Check the thermistor. If normal, replace the out-
door controller board.
LD4
High pressure switch (63H2)
function
● 62H2 was badly connected.
● 63H2 was working.
● Check 63H2 and the outdoor fan motor.
● Check if refrigerant supply is low.
● Check if air cycle is short-cycled.
LD5
Thermal relay (51C) function ● 51C was connected incor-
rectly.
● 51C was working.
● Check 51C, the compressor, and power supply.
LD6
Thermal switch (26C) function. ● 26C was connected incor-
rectly.
● 26C is working.
● Check 26C.
● Check if refrigerant supply is low.
● Check if the capillary tube is clogged.
LD7
Over heat protection ● The thermistor is broken.
● Coil temperature is over
153˚F.
● Measure the resistance of the thermistor.
● Check the outdoor fan motor.
● Check if air cycle is short-cycled.
LD8
Input circuit of outdoor con-
troller board is abnormal.
● Pulse input is abnormal. ● Replace the outdoor controller board.
Cause
1) Indoor/outdoor connecting wires are poorly connected.
(Refer to next page.)
2) Power supply is poorly connected.
3) Connector or transformer is broken.
4) Fuse (6A) in the outdoor controller board is blown.
Check points
1) Check the connecting wires.
2) Check the power supply.
3) Check connectors and transformers.
4) Check the fuse.
4. TROUBLESHOOTING ACCORDING TO CHECK CODE
5.WHEN OUTDOOR UNIT DOES NOT WORK
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