Service manual

Troubleshooting by Indication on the Remote Controller SiUS28-902_a
123 Troubleshooting
3.30 “L5” Outdoor Unit: Inverter Compressor Abnormal
Remote
Controller
Display
L5
Applicable
Models
RZQ18~30PVJU
Method of
Malfunction
Detection
Malfunction is detected from current flowing in the power transistor.
Malfunction
Decision
Conditions
When an excessive current flows in the power transistor.
(Instantaneous overcurrent also causes activation.)
Supposed
Causes
 Defect of compressor coil (disconnected, defective insulation)
 Compressor start-up malfunction (mechanical lock)
 Defect of inverter P.C.B.
Troubleshooting
Higher voltage than actual is displayed when the inverter output voltage is checked by tester.
Caution
Be sure to turn off the power switch before connecting or disconnecting
the connector, or parts could be damaged.
Compressor inspection
Inverter
output
voltage check
Inverter output
voltage is not balanced.
(Normal if within ±5V Must
be measured when
frequency
is stable.
Replace the compressor.
Compressor inspection
Inspect according to the diagnosis
procedure for odd noises,
vibration, and operating status of
the compressor.
NO
Replace the inverter unit.
YES
YES
Correct power supply.
YES
The compressor's
coil is disconnected or the
insulation is
defective.
NO
NO
Disconnect the connection
between the compressor and
inverter. Make the power
transistor check mode setting
ON by service mode.
There is
instantaneous power
drop.