Mitsubishi Electric e Series Service Handbook page 65

[ III Unit Components ]
4. Inverter board (INV board)
IGBT (rear)
SC-L1
Input (L1)
SC-L2
Input (L2)
SC-L3
Input (L3)
SC-U
Inverter output (U)
SC-V
Inverter output (V)
SC-W
Inverter output (W)
1) When opening or closing the front panel of the control box, do not let it come into contact with any of the internal components.
Before inspecting the inside of the control box, turn off the power, keep the unit off for at least 10 minutes, and confirm that
the voltage across pins 1 and 5 of connector RYPN has dropped to 20 VDC or less. It takes about 10 minutes to discharge
electricity after the power supply is turned off.
2) A Faston terminal on the inrush current resistor has a locking function. Make sure the cable heads are securely locked in
place. Press the tab on the terminals to remove them.
3) Control box houses high temperature parts. Be well careful even after turning off the power source.
4) Perform the service after disconnecting the relay connector (RYFAN1A, RYFAN1B). Before plugging in or unplugging
connectors, check that the outdoor unit fan is not rotating and that the voltage across pins 1 and 5 of connector
RYPN is 20 VDC or less. The capacitor may collect a charge and cause an electric shock when the outdoor unit fan
rotates in windy conditions. Refer to the wiring nameplate for details.
5) After servicing, reconnect the relay connector (RYFAN1A, RYFAN1B) of the fan as it was.
6) When the power is on, the compressor or heater is energized even while the compressor is stopped. Before turning on the
power, disconnect all power supply wires from the compressor terminal block, and measure the insulation resistance of the
compressor. Check the compressor for a ground fault. If the insulation resistance is 1.0 MΩ or below, connect all power supply
wires to the compressor and turn on the power to the outdoor unit. It is energized to evaporate the liquid refrigerant that has
accumulated in the compressor.
HWE20010
CN19V CNCT2
1 18VDN Connects to ACCT
2 GND with lead wire
- 56 -
CN-P, CN-N
Connects to connector
RYPN
SC-P
DCL terminal
SC-P1
DCL terminal
CNRY
1 12 VDC
2 GND (Power-supply board)
LED1
Lit: Inverter operation
Blinking: Inverter error
LED4
Lit: Microcomputer is energized.
Unlit: Microcomputer is not energized.
CN2
Serial communication signal
1 Signal input
2 GND (MAIN circuit board)
3
Signal output
4 GND (MAIN circuit board)
GB