70
Installation and Maintenance
Service Manual
38
Zero-crossing
malfunction of
outdoor unit
U9
During cooling and drying
operation, compressor and
outdoor fan stop while indoor
fan operates. During heating
operation, all loads stop.
Hardware malfunction
of outdoor units main
board;
1. Replace outdoor units
main board AP1;
39
Limit/decrease
frequency due to
freeze protection
FH
All loads operates normally,
while operation frequency of
compressor decreases.
Poor air return of
indoor unit or speed of
fan is too low
1. Check whether indoor
units horizontal louver
can close normally →
replace indoor units main
board → replace indoor
units motor;
●Discharging method
(1) remove the inverter cover(Outdoor Unit)
(2)As shown below,connect the discharge resistance(approx.100Ω20W)or plug of the sold ering iron to voltage between + - terminals of
the electrolytic capacitor on PC Board for 30s, and then peformedischarging.
NOTE:
A large-capacity electrolytic capacitor is used in the outdoor unit controller(inverter).Therefore,if the power supply is turned
off,charge(charging voltage DC280V to 380V)remains and disc harging takes a lot of time.. After turning off the power source,if touching
the charging section before discharging, an electrical shock may be caused. Discharge the electrol ytic capacitor completely by using
soldering iron,etc.
P.C.board
(Soldered surface)
Inverter cover
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