Mitsubishi Heavy Industries SRRM40HENG-L, Handbook, Page: 935 / 1106

FDC-HKX
933
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
2
:2.50 open/2.06 close, Mpa (25.5 open/
21close kgf/cm
2
)[FDCP:2.79open/2.26 clope, MPa(28.5open/23 cloes kgf/cm 2 )], current safe control or dis-
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.)
Is 52C turned ON?
Inspect outdoor con-
trol PCB.
Defective inverter PCB.
Replace.
Check wiring between
capacitor ~ CNW, and
connectors.
YES
NO
Is LED1 (green)
on inverter PCB
flashing?
YES
NO
Does inverter
LED2 (red) light or
flash?
NO
(See page 934)
Check error detail of LED2
(red).
Are voltages detected
at U, V and W of power
transistor module?
YES
YES
1
Is DC 540V
detected at CNW on
inverter PCB?
NO
YES
NO
NO
NO
NO
NO YES
YES
Is DC 540V
detected between
(+)~(-)?
NO
Is capacitor
normal?
YES
Is there continuity
on reactor?
Compressor check
YES
Is resistance
detected on resistor
R
1
?
YES
Is diode module
normal?
YES
Is there continuity
on noise filer?
Check 52C.
NO
2
Capacitor is defective.
Replace.
Reactor is defective.
Replace.
Resistor R1 is defective.
Replace.
Diode module is defective.
Replace.
Noise filter is defective.
Replace.
Defective power transistor
module or inverter PCB
Replacement
3
4
5
6
7