Mitsubishi Electric CITY MULTI PUHY-P108 Service Handbook page 255

[ IX Troubleshooting ]
Error Code
4108 Overcurrent
protection
4115 Power supply
sync signal ab-
normality
4116 Motor abnor-
mality
Error definition and error
detection method
1. First detection (1) Overload operation that
If 51C2 is started dur-
ing the operation of
(2) Power supply error
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
(3) Faulty wiring
of the over-current re-
lay: 43A)
(4) Compressor failure
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.
The frequency cannot be (1) Power supply error
determined when the
power is switched on.
(2) A fuse is blown
(3) Faulty wiring
(4) Main board failure
1. LOSSNAY (1) Board failure
The motor keep running
(2) Motor malfunction
even if the power is OFF.
(3) Solenoid switch malfunc-
The 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.
Cause
exceeds unit use limit
Power-supply voltage
drop
Open phase of power
supply voltage
Compressor open phase
or grounding fault
Compressor lock
tion
- 246 -
Check method and remedy
Check the unit working condition.
Check the voltage of the power sup-
ply terminal block (TB1).
Check for open phase.
Check 52C2 connector and the wir-
ing.
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.
Check the voltage of the power sup-
ply terminal block (TB1).
Check the fuses on the main board
(F01 and F02).
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.
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.
Replace the board.
Check for the motor and the solenoid
switch.