Outdoor Unit Inverter Board (Inv Board) - Mitsubishi Electric PUHY-P250YNW-A Service Handbook

[4-2 Circuit Board Components ]
4-2-3

Outdoor Unit Inverter Board (INV Board)

C700, C701,
C705, C706
Smoothing capacitor
CN-P, CN-N
Connects to connector
RYPN
SC-L3
Input (L3)
SC-PL
DCL terminal
IGBT (rear)
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 (RYFAN1). 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 (RYFAN1) of the fan as it was.
6) When the power is turned on, the compressor is energized even while it is not operating. Before turning on the power, discon-
nect 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. The liquid refrigerant in the compressor will evaporate by energizing
the compressor.
BS_04_C
CNCT2
Connects to ACCT
with lead wire
SC-L2
Input (L2)
SC-P1
DCL terminal
CNRY
12 VDC
GND
(Power-supply board)
SC-L1
Input (L1)
LED1
Lit: Inverter operation
Blinking: Inverter error
LED4
Lit: Microcomputer is
energized.
Unlit: Microcomputer
is not energized.
CT003
DCCT for overcurrent
detection
CN2
Serial communication
signal
Signal input
GND
(MAIN circuit board)
Signal output
CN19V
GND
18 VDC
(MAIN circuit board)
GND
7
chapter 4 -