Service manual
Table Of Contents
- TopPage
- SPECIFICATIONS
- EXPLANATION OF CIRCUIT AND OPERATION
- [1] BLOCK DIAGARM
- [2] FUNCTIONS
- 1. FREQUENCY CONTROL
- 2. OVER CURRENT PROTECTION
- 3. COMPRESSOR PROTECTION CONTROL
- 4. POWER TRANSISTOR MODULE PROTECTION
- 5. SERIAL SIGNALS
- 6. THERMISTOR OPEN OR SHORT
- 7. MISWIRING CHECK
- 8. SAFETY TIME
- 9. PUMP DOWN SWITCH
- 10. CONTROL OF COMPRESSOR OR AND EXPANSION VALVE
- 11. DEFROST OPERATION
- 12. Power factor module Output voltage
- [3] ACTIVE FILTER CIRCUIT
- [4] EXPLANATION OF IPM DRIVE CIRCUIT
- FUNCTION AND OPERATION OF PROTECTIVE PROCEDURES
- REFRIGERATION CYCLE
- DISASSEMBLING PROCEDURE
- PartsGuide
- EndPage
3 – 8
2. When one room is not cooled (other rooms are cooled)
3. When all rooms are not heated
Yes
Yes
No
Yes
No
No
No
Yes
No
No
Yes
Yes
Short circuit of the thermistor error
Open circuit of the thermistor error
Open circuit of serial signal line
Short circuit of serial signal line
Is the timer lamp of the
indoor unit in the room
not cooled flashing ?
Press the OPERATION
button to start operating
the air-conditioner.
(Set the cooling mode
to 18ºC.)
Is the timer lamp of the
indoor unit in the room
not cooled flashing ?
Check that the power
between the terminal
board "N" and "1" of the
indoor unit is AC 230V.
Repair the wiring
between the units.
Replace the indoor
control PWB.
Replace the thermistor.
Check the failure
symptom with the failure
diagnosis mode.
Replace the outdoor control PWB
or the expansion valve (UNIT A)
or the expansion valve (UNIT B)
or the expansion valve (UNIT C)
Is the resistance value of the
winding in the fan motor ?
Abnormal fan motor of
indoor unit
Replace the indoor fan motor.
Is the wiring between the
units connected by mistake
or broken ?
Repair the wiring between
the units.
Replace the indoor control PWB.
Is the resistance value of the ther-
mistor for UNIT A (TH6), UNIT B
(TH7) or UNIT C (TH8)
Does the air get cooler in the cooling operation mode?
Check the four-way valve. Has the cycle been switched?
Is AC230V applied between the connector
(CN4) 1 and 3 of the 4-way valve ?
Replace the 4-way valve.
Replace the outdoor control P.W.B..
Pressure check
The heating cycle is normal.
Press the ON switch on the remote control to run the air conditioner.
Set the temperature to 32ºC in the heating mode and start operation.
Is the outdoor compressor running?
Yes
Yes
To
No
No
Yes
Yes
No
No
No
A
Refer to 1 All rooms are not cooled.