Checking The Installation Conditions; Solutions For The Main Breaker Trip - Mitsubishi Electric HP120TNU-A Service Handbook

[8-10 Troubleshooting Inverter Problems ]
8-10-10

Checking the Installation Conditions

Items to be checked
(1) Check refrigerant charge.
(2) Check outdoor unit branch in-
stallation.
8-10-11

Solutions for the Main Breaker Trip

Items to be checked
[1] Check the breaker capacity.
[2] Perform Meg check between the
terminals on the power terminal
block TB1.
[3] Turn on the power again and
check again.
[4] Turn on the outdoor unit and check
that it operates normally.
50
- chapter 8
Phenomena
Overcharge of refrigerant
The branch approach <500 mm.
Is the branch angle < ±15° to horizontal? Make branch angle < ±15°
Phenomena
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
Remedy
Return to correct refrigerant
charge.
Make branch approach >500mm
Remedy
Replace it with a specified breaker.
Check each part and wiring.
Refer to the following page(s). [8-10-13
Simple Check on Inverter Circuit Compo-
nents]
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 [8-10-2 Checking the
Inverter Board Error Detection Circuit] -
[8-10-9 Checking the Fan Board for
Damage with Load]
HWE18220_GB