Mitsubishi Electric CAHV-R450YA-HPB Service Manual page 159

[ X Troubleshooting ]
(2) Inverter output related troubles
[1] (1)
Check the
INV board er-
ror detection
circuit.
(2)
[2] Disconnect the compressor
Check for wiring, and check the com-
compressor pressor Meg, and coil resis-
ground fault tance.
or coil error.
[3] (1)
Check wheth-
er the inverter
is damaged.
(No load)
(2)
(3)
(4)
HWE22020
Items to be checked
Disconnect the invert-
er output wire from
the terminals of the
INV board (SC-U,
SC-V, SC-W).
Put the outdoor unit
into operation.
Disconnect the invert-
er output wire from
the terminals of the
INV board (SC-U,
SC-V, SC-W).
Apply the power.
Turn on SW5-10 and
SW6-9, select the
item code [1092], set
the LED display to
[0001], and press
SWP3.
Put the outdoor unit
into operation.
Check the inverter
output voltage after
the inverter output
frequency has stabi-
lized.
Phenomena
1) Overcurrent error
(4250 Detail code No. 101, 104,
105, 106, and 107)
2) Logic error
(4220 Detail code No. 111)
3) ACCT sensor circuit failure
(5301 Detail code No.117)
4) IPM open
(5301 Detail code No.119)
1) Compressor Meg failure
Error if less than 1 M ohm.
2) Compressor coil resistance failure
Coil resistance value of 0.212 ohm
(20°C)
1) Inverter-related problems are de-
tected.
2) Inverter voltage is not output at the
terminals (SC-U, SC-V, and SC-W)
3) There is an voltage imbalance be-
tween the wires.
Greater than 5% imbalance or 5V
4) There is no voltage imbalance be-
tween the wires.
- 150 -
Remedy
Replace the INV board.
Replace the INV board.
Replace the INV board.
Normal
Check that there is no liquid re-
frigerant in the compressor.
If there is none, replace the com-
pressor.
Replace the compressor.
*Select item code [1092], set the
LED display to [0000] and press
SWP3, and set SW5-10, SW6-10
on the main board back to as it
was. Go to section [1].
Replace the INV board.
Replace the INV board.
Normal
*Select item code [1092], set the
LED display to [0000] and press
SWP3, and set SW5-10, SW6-10
on the main board back to as it
was.
GB