Service manual

SiUS28-902_a Troubleshooting by Indication on the Remote Controller
Troubleshooting 126
3.32 “L9” Outdoor Unit: Inverter Start up Error
Remote
Controller
Display
L9
Applicable
Models
RZQ18~30PVJU
Method of
Malfunction
Detection
Malfunction is detected from current flowing in the power transistor.
Malfunction
Decision
Conditions
When overload in the compressor is detected during startup
Supposed
Causes
 Defect of compressor‘
 Pressure differential start
 Defect of outdoor unit P.C.B. (A1P)
Troubleshooting
Caution
Be sure to turn off the power switch before connecting or disconnecting
the connector, or parts could be damaged.
Inverter
output
voltage check
Inverter output voltage
is not balanced.
(Normal if within ±5V)
Must be measured
when frequency
is stable.
Unsatisfactory pressure
equalization
Check refrigerant system.
Compressor inspection
Inspect according to the diagnosis
procedure for odd noises, vibration
and operating status of the
compressor.
YES
Replace outdoor unit P.C.B.
(A1P).
NO
NO
Reset and restart.
NO
The difference
between high and low
pressure when starting
is above
30psi.
YES
YES
Disconnect the connection
betw
een the compressor and
inverter. Make the power
transistor check mode ON by
service mode.
After turning
on again, "L9" blinks
again.