Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 935

2) When the heating effect is insufficient
• Check if the protective function (1) has operated and, as a result, the compressor operation frequency has dropped
below the specified frequency.
Note (1) The frequency drops when the high pressure control (Operated at 63H
21close kgf/cm
charge temperature control is operated.
• Does the indoor expansion valve operate normally? Is the valve clogged?
(3) Trouble diagnosis at the inverter side
When any defect is found at the inverter side as a result of the trouble diagnosis of (2), (c), inspect with the
following procedures.
(a) Diagnosis procedures (Regarding the ditails of 1~7, refer to the inspection points of indoor unit on the next page.)
Check error detail of LED2
(red).
(See page 934)
Defective power transistor
module or inverter PCB
Replacement
2
)[FDCP:2.79open/2.26 clope, MPa(28.5open/23 cloes kgf/cm
Is 52C turned ON?
YES
NO
Is LED1 (green)
on inverter PCB
flashing?
YES
YES 1
Does inverter
LED2 (red) light or
flash?
NO
NO 2
Are voltages detected
at U, V and W of power
transistor module?
YES
Compressor check
YES
Check 52C.
:2.50 open/2.06 close, Mpa (25.5 open/
2
NO
Inspect outdoor con-
trol PCB.
Is DC 540V
YES
detected at CNW on
inverter PCB?
NO
Is DC 540V YES
detected between
(+)~(-)?
NO
3
NO
Is capacitor
normal?
YES
4
NO
Is there continuity
on reactor?
YES
5
Is resistance
NO
detected on resistor
R ?
1
YES
6
Is diode module
NO
normal?
YES
7
NO
Is there continuity
on noise filer?
FDC-HKX
2 )], current safe control or dis-
Defective inverter PCB.
Replace.
Check wiring between
capacitor ~ CNW, and
connectors.
Capacitor is defective.
Replace.
Reactor is defective.
Replace.
Resistor R1 is defective.
Replace.
Diode module is defective.
Replace.
Noise filter is defective.
Replace.
933