Mitsubishi Electric HP120TNU-A Service Handbook page 108

[4-2 Outdoor Unit Circuit Board Components ]
(2) YNU
CN-CAP
Connects to INV42Y
N
N
C1-C4
Smoothing capacitor
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 capacitor voltage (inverter main circuit) 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, RYFAN2). 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, RYFAN2) of the fan as it was.
HWE18220_GB
FT-P1C
Connects to INV42Y
13
chapter 4 -