Mitsubishi Electric PUHY-P168, Service Handbook, Page: 255 / 404

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[
IX
Troubleshooting ]
4108 Overcurrent
protection 1. First detection
If 51C2 is started dur-
ing the operation of
No.2 compressor, the
outdoor unit stops
once, turns to anti-re-
start mode for 3 min-
utes, and restarts after
3 minutes. (Set value
of the over-current re-
lay: 43A)
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.
4115 Power supply
sync signal ab-
normality The frequency cannot be
determined when the
power is switched on. (1) Power supply error Check the voltage of the power sup-
ply terminal block (TB1).
(2) A fuse is blown Check the fuses on the main board
(F01 and F02).
(3) Faulty wiring Measure 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.
If the voltage (AC208/230V) is not
the same as the power supply volt-
age, the wiring is faulty.
(4) Main board failure If none of the items described above
is applicable, and if the trouble reap-
pears even after the power is
switched on again, replace the MAIN
board.
4116 Motor abnor-
mality 1. LOSSNAY
ΠThe motor keep running
even if the power is OFF.
ΠThe thermal overload re-
lay is ON. (Only for the
three-phase model)
2. Indoor unit
If detected less than
180rpm or more than
2000rpm, the indoor
unit will restart and
keep running for 3
minutes.If detected
again, the display will
appear.
(1) Board failure Replace the board.
(2) Motor malfunction
(3) Solenoid switch malfunc-
tion
Check for the motor and the solenoid
switch.
Error Code
Error definition and error
detection method
Cause Check method and remedy