Mitsubishi Electric CITY MULTI CMB-P1016V-F, Service Handbook

Page: 91 / 183

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Treatment of Inverter Output Related Troubles 2)
Check item Phenomena Treatment
[1]
Check the
INV board
error
detection
circuit. Perform the following:
1
Disconnect INV board
CNDR2. After removing, turn
on the outdoor unit and check
the error status. (The
compressor does not operate
because CNDR2, which
carries the IPM drive signal,
has been disconnected.)
1
IPM/overcurrent error.
(4250 detailed No. 101, 102, 103,
104, 105, 106, 107) · Replace INV board.
[2]
Check for
compressor
ground fault
or coil error. Disconnect the compressor wir-
ing, and check the compressor
Meg, and coil resistance.
1
Compressor Meg failure
Error if less than 1M
Ω
.
❇
When no refrigerant is
accumulated in the compressor.
2
Compressor coil resistance failure
Coil resistance value of 0.58
Ω
(20
°
C)
· Replace compressor
Check whether the refrigerant is accumu-
lating in the compressor again.
[3]
Check to see
if the inverter
is damaged.
❇
Perform this
check if an
error occurs
immediately
before or
after turning
on the com-
pressor.
Perform the following:
1
Reconnect the connector re-
moved at item [1].
2
Disconnect the compressor
wiring.
3
Turn on SW1-1 on the INV
board. Operate the outdoor
unit after above steps. Check
the inverter output voltage.
❇
It is recommend to use the
tester used to determine the
¶
[1] (7) 5) IPM troubleshooting
when checking the inverter
output voltage.
❇
Measure when the inverter
output frequency is stable.
1
IPM/overcurrent error.
(4250 detailed No. 101, 102, 103,
104, 105, 106, 107)
2
There is a high possibility of an
inverter circuit error if the voltage
unbalance across all wiring is
greater than 5% or 5V.
3
No voltage unbalance across all
wiring
2
No voltage unbalance across all
wiring
· Refer to item [5] for inverter circuit trouble.
[4]
Check to see
if the inverter
is damaged.
❇
Perform this
check if an
error occurs
during
steady op-
eration.
Turn on the outdoor unit.
Check the inverter output volt-
age.
❇
It is recommend to use the
tester used to determine the
¶
[1] (7) 5) IPM troubleshooting
when checking the inverter
output voltage.
❇
Measure when the inverter
output frequency is stable.
1
There is a high possibility of an
inverter circuit error if the voltage
unbalance across all wiring is
greater than 5% or 5V. · Refer to item [5] for inverter circuit trouble.
See item [2].
Proceed to item [5] however if there is no
problem at [2]. Replace the compressor if
there is no problem at [5].
See item [2].
Proceed to item [5] however if there is no
problem at [2]. Replace the compressor if
there is no problem at [5].
2
ACCT sensor circuit error.
(5301 detailed No. 117) See to
¶
[1] (7) 4)
"Current Sensor ACCT"
Check the resistance and replace if
erroneous. Replace the INV board if the
ACCT status is normal.
3
DCCT sensor circuit error.
(5301 detailed No. 118) · Replace DCCT
Turn on the outdoor unit again after
replacing the DCCT. If an error occurs:
· Replace the INV PCB
(The DCCT condition can be regarded as
normal.)
4
ACCT sensor circuit error.
(5301 detailed No. 115) · INV board error detection circuit is normal.
Because IPM can not drive, if the CNDR2
is disconnected.