Mitsubishi Electric CAHV-R450YA-HPB Service Manual page 161

[ X Troubleshooting ]
[8] Put the outdoor unit into oper-
Check whether ation.
the converter Check the BUS voltage after
is damaged. the converter circuit went into
(During Com- operation and the BUS voltage
pressor Opera- has boost.
tion) *The voltage generally boost
at or above 80 rps, depending
on the power source voltage.
(3) Trouble treatment when the main power breaker is tripped
Items to be checked
[1] Check the breaker capacity.
[2] Perform Meg check the terminals
on the power terminal block.
[3] Turn on the power again and
check again.
[4] Turn on the outdoor unit and check
that it operates normally.
HWE22020
Items to be checked
Use of a non-specified break-
er
Zero to several ohm, or Meg
failure
1) Main power breaker trip
2) No remote control display
1) Operates normally without
tripping the main breaker.
2) Main power breaker trip
Phenomena
BUS voltage does not boost (does not
change) BUS voltage does not boost to
approximately between 650 and 750
VDC, or the following errors are detect-
ed.
Error code: 4220
Detail code: 123
An overcurrent error occurs after con-
verter circuit goes into operation.
Error code: 4250
Detail code: 121, 122
An overvoltage error occurs after con-
verter circuit goes into operation.
Error code: 4220
Detail code: 109, 110, 112
Phenomena
- 152 -
Remedy
Replace the INV board.
a. If the problem persists af-
ter startup, replace the INV
board.
b. If the problem persists af-
ter replacing the INV
board, replace the DCL.
a. If the problem persists af-
ter startup, replace the INV
board.
b. If the problem persists af-
ter replacing the INV
board, replace the DCL.
Remedy
Replace it with a specified breaker.
Check each part and wiring.
*Refer to "(5) Simple checking procedure
for individual components of main inverter
circuit". (page 154)
IGBT module
Rush current protection resistor
Electromagnetic relay
DC reactor
a) The wiring may have been short-circuit-
ed. Search for the wire that short-circuit-
ed, and repair it.
b) If item a) above is not the cause of the
problem, refer to (2)-[1]-[6]. (page 150)
GB