Checking The Inverter For Damage At No-Load - Mitsubishi Electric PUHY-M200YNW-A1 Service Handbook

[8-10 Troubleshooting Inverter Problems ]
8-10-4

Checking the Inverter for Damage at No-Load

Items to be checked
(1) Stop the unit.
Remove power supply.
(2) Disconnect the inverter
output wires from the
compressor terminals (U,
*1
V, W).
(3) Set SW7-1 on the MAIN
board to ON.
(4) Apply power supply.
(5) Put the outdoor unit into
operation.
Check the inverter output
voltage after the inverter
output frequency has sta-
bilized.
*1 Output voltage is present at the inverter output wiring terminal. To avoid short-circuiting and ground fault, do not let the
terminal come in contact with the unit or the compressor, and use caution not to damage the terminal.
*2 Compressors on M200, M250, and M300 models are located in the back of the MAIN BOX. To disconnect the inverter out-
put wiring, move the MAIN BOX out of the way first, and then disconnect the wiring from the terminal on the compressor.
Refer to [8-13-1 Ensuring Maintenance Space (Preparation for the Maintenance of Refrigerant Circuit Parts)] for how to
move the MAIN BOX.
BS_08_E
Phenomena
1) Inverter-related problems are detected.
2) Inverter voltage is not output at the termi-
nals (U, V, and W)
3) There is an voltage imbalance between
the wires.
Greater than 5% imbalance or 5V
4) There is no voltage imbalance between
the wires.
Remedy
Set SW7-1 on the MAIN board to ON,
and go to [8-10-2 Checking the Invert-
er Board Error Detection Circuit].
Replace the INV board.
Replace the INV board.
Normal
*When done checking, set SW7-1 on
the MAIN board back to as it was.
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