Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 67

5300 (UH): Current sensor trouble
Abnormal points and detection methods
The detected current sensor input value (primary current)
during compressor operation is outside the specified
range.
Diagnosis of failure
Check the input current at the time of abnormal
stop.
3-phase
Is the power supply 1-phase or
3-phase?
Does it satisfy the condition 1 in the
lower right?
Check the compressor wiring for disconnection
or looseness.
Is there any abnormality such as
disconnection or looseness?
OCH800A_67
1-phase
Yes
No
Yes
No
Causes and checkpoints
• Decrease/Trouble of power supply voltage
• Disconnection of compressor wiring
• Input sensor trouble on outdoor power circuit board
• Wiring through current sensor (penetration type) is
not done.
The power supply voltage is decreased or
abnormal.
Check the power supply facility.
Condition 1:
Model Error detecting condition
1-phase 37 A or more for 10 consecutive
model seconds, or 40 A or more
Connect the compressor wiring properly.
Replace the outdoor power circuit board
(Malfunction of current sensor circuit).