Mitsubishi Electric PU(H)Y-P250YGM-A, Service Handbook

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[
IX
Troubleshooting ]
4103 Reverse
phase/open
phase 1.The operation cannot
be started because of
the reserve phase of
one of the power lines
(L1 or L2).
(1) Faulty wiring ΠCheck whether the phase of
the power supply terminal
block (TB1) is normal.
ΠCheck the wiring between the
power supply terminal block
(TB1) and the main boards
(CN20 and CN21).
(2) Main board failure. If the above faults are not found, the
main board is faulty.
2.When turning on the
power, the operation
cannot be started be-
cause of the open
phase of one of the
power lines (L1, L2 or
L3).
(1) Power supply error
ΠOpen phase of power
supply voltage
ΠPower-supply voltage
drop
Check the input resistance of the
power supply terminal block (TB1).
(2) Faulty wiring
Between the power sup-
ply terminal block (TB1)
and the main boards
(CN20 and 21)
ΠMeasure voltages of pin 5 of the
male connector (CN20) on the
main board and between pins 1
and 3 of the male connector
(CN21) on the main board.
ΠIf the voltage is not the same as
the power supply voltage, the
wiring is faulty.
(3) A fuse is blown. Check whether the fuses of the main
board (both F01 and F02) are not
blown.
(4) Main board failure If the above faults are not found, the
main board is faulty.
4108 Overcurrent
protection 1.First detection
If 51C2 is started dur-
ing the operation of
No.2 compressor, the
outdoor unit goes into
20-second restart
mode, then the out-
door unit will start in
20 seconds. (Set val-
ue of the over-current
relay: 17.5A)
2.Second detection
If 51C2 is started
again within a minute
after restarting in com-
pliance with 1. above,
the unit makes an er-
ror stop and the error
code "4108" will ap-
pear.
3.There will be a minute
grace period of an er-
ror stop when No.2
compressor restarts
after the outdoor unit
stops and LED indi-
cates, which means
the grace period, will
appear.
(1) Overload operation that
exceeds unit use limit
Check the unit working condition.
(2) Power supply error
ΠPower-supply voltage
drop
ΠOpen phase of power
supply voltage
Check the voltage of the power sup-
ply terminal block (TB1).
Check for open phase.
(3) Faulty wiring Check 52C2 connector and the wir-
ing.
(4) Compressor failure
ΠCompressor open phase
or grounding fault
ΠCompressor lock
Check the wiring and apply a meg-
ger to the compressor.
Start operation under no-load condi-
tions.
Remove the power wire on the com-
pressor-side, insulate the power line
and start operation.
-> The compressor is faulty if
52C2 normally turns on.
Error Code
Error definition and error
detection method
Cause Check method and remedy
TB1
L1 CN20 5Pin
N CN21 3Pin
L2 CN21 1Pin
Pin