Mitsubishi Electric PUHY-P168, Service Handbook

Page: 286 / 404

- 277 -
[
IX
Troubleshooting ]
4108 Overcurrent
protection
1. First detection
If 51C2 is started during
the operation of No.2 com-
pressor, the outdoor unit
stops once, turns to anti-
restart mode for 3 minutes,
and restarts after 3 min-
utes. (Set value of the
over-current relay: 43A)
2. Second detection
If 51C2 is started again
within a minute after re-
starting in compliance with
1. above, the unit makes
an error stop and the error
code "4108" will appear.
3. There will be a minute
grace period of an error
stop when No.2 compres-
sor restarts after the out-
door unit stops and LED
indicates, 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
Œ
The motor keep run-
ning even if the pow-
er is OFF.
Œ
The thermal over-
load relay 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