Mitsubishi Electric NTXMSM36A142BA Technical & Service Manual page 89

Check code
5300
(UH)
Abnormal points and detection methods
If any of the following conditions is detected:
Primary current sensor detects any of the following conditions (single
1
phase unit only):
Model name
NTXMSM36/48
NTXMSH36/42/48
NTXMSM60
Secondary current sensor detects 25 A or more.
2
Secondary current sensor detects 1.0 A or less.
3
●Diagnosis of defects
Make sure to turn the power OFF before connecting/disconnecting
any connectors, or replacing boards.
Check the power specification of the
outdoor unit.
Is the power supply single phase?
No
(3-phase)
Does it satisfy the condition
Check the value on the secondary current
sensor during the error.
Does it satisfy the
condition
2
No
OCHT810A
Primary current error
10 consecutive-
One-time detection
second detection
34 A 38 A
37 A 40 A
Diagnosis
Yes
(1-phase)
?
1
No
Check the compressor wiring.
Yes
or ?
3
Is there any abnormality
such as disconnection,
looseness, or breakage?
Causes and checkpoints
Decrease/trouble of power supply voltage
Disconnection of compressor wiring
Current sensor trouble on outdoor power circuit
board
Wiring through current sensor (penetration type) is
not done.
The power supply voltage might be
decreased or abnormal.
Check the power supply facility.
The secondary current sensor value during the error can be displayed
by an operation of SW1 on the outdoor multi controller circuit board.
SW1 Setting
Display on LED1, 2
ON
0–999.9
OFF
1 2 3 4 5 6 7 8
Connect the compressor wiring properly.
Yes
No
Replace the outdoor power circuit board
(Malfunction of current sensor circuit).
89
Remedy
Unit
Arms