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11-2. Troubleshooting Using the Self-Diagnostic Monitor
11-2-1. Method of Self-Diagnosis
If the service lamp of the indoor unit flashes every half-second, carry out
detailed troubleshooting using the following method.
●
If the service lamp flashes every half-second as soon as the power is
plugged in, there is either a faulty external ROM (for OTP data) on the board
of the indoor unit, an insertion fault, or the ROM is not installed.
●
Even when power is not being supplied, the malfunction mode will remain in
memory, so carry out the diagnosis as follows:
Procedure
(1) Restore power.
(2) Set the operation selector of the indoor unit to OFF (Self-Diagnosis).
(3) If an abnormality is sensed or an automatic protective action is taken, the self-diagnostic lamps No. 1, 2 and 3
respectively alternately blink (on) for 5 seconds and off for 2 seconds (the buzzer sounds when they go off).
When there is no abnormality detected, there will be no indication on the self-diagnostic lamp (ser-
vice lamp), nor will the buzzer sound.
(4) The buzzer sounds three times to inform that the diagnosis has been completed.
(5) After the repair, always set the operation selector to DEMO and restore power to delete the contents of the
diagnosis. After that, set the operation selector to OFF to check that the contents were deleted.
11-2-2. Details of Diagnosis
NOTE
NOTE
Operation selector
Normally set it to ON position.
OFF, TEST and DEMO positions
are used for inspections, etc.
TEST
ON
OFF
DEMO.
Operation
Service
*
Timer
Details of Diagnosis
Details of Abnormality
Room temp. sensor abnormality
➀
Sensor open- and short-circuit
➁
Connector contact fault
Indoor heat exchanger temp.
sensor abnormality
➀
Sensor open- and short-circuit
➁
Connector contact fault
Compressor temp. sensor and SH
(SVC) sensor abnormality
➀
Sensor open- and short-circuit
➁
Connector contact fault
Outdoor heat exchanger temp.
sensor abnormality (Narrow tube
A/B temperature sensor)
➀
Sensor open- and short-circuit
➁
Connector contact fault
Outdoor temp. sensor abnormality
(Wide tube A/B temperature sensor)
➀
Sensor open- and short-circuit
➁
Connector contact fault
CT (current detection sensor)
abnormality
➀
Sensor open- and short-circuit
➁
Connector contact fault
➂
HIC fault (no output from U, V and W phases)
Display Lamp
●
…Illuminated
…Flashing …Off
Defective serial communication
No power output to the outdoor unit,
or no current flow on the outdoor
board
➀
Incorrect wiring of F cable, incorrect insertion, or the
contact between metal parts and electric leads.
➁
Abnormality on 200 VAC / 280 VDC line
➂
Defective insulation
➃
Blown terminal block temperature fuse
➄
Defective power relay
➅
Defective boards (indoor or outdoor)
●
●
➀
Defective HIC
➁
Faulty contact / crimp of signal lead connector
➂
Locked and worn AC compressor
➃
Defective outdoor A board, or mistake on model change
➄
Outdoor fan motor fails to rotate, or outdoor heat
exchanger blocked
Protector for HIC/Power Transistor
activated (current and temperature)
*
This lamp lights only when conducting service inspections.
