Multi F Four-Way Ceiling Cassette Service Manual

Part 5. Trouble Shooting
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Only for training and service purposes
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62
Heatsink High error
Inverter PCB heatsink
temperature is over 85°C
1. ODU fan locking
2. Heatsink assembly of INV PCB assemble condi-
tion abnormal
3. Defect of temperature sensing circuit part defect
of INV PCB
Display
code
Title Cause of error Check point & Normal condition
■ Error Diagnosis and Countermeasure Flow Chart
Is installation
condition normal ?
No
Yes
1. Check fan locking
2. Check covering of heat exchanger
3. Check distance between ODU and obstacles
4. Check pipe distortion and abnormality
5. Check service valve is opened
→ Eliminate causes for abnormal condition
Check resistance between NO.19 pin and NO.20 pin
of PFC module
Check resistance between NO.24 pin and NO.25 pin
of PFC module
→ 7KΩ10%(at 25°C)
→ Replace PCB if abnormality found
Is assemble condition
of INV PCB heatsink normal ?
Is PCB temperature
sensing part normal ?
No
No
Yes
Check assemble condition between INV PCB heatsink and
PFC & IPM module → Reassemble if abnormality found
Recheck installation condition
and connection of Heat sink
Yes
Check Point
1. Check resistance between No.19 pin and NO.20 pin of PCB PFC module
2. Check resistance between No.24 pin and NO.25 pin of PCB PFC module - only 48/56k
3. Resistance value should be in 7kΩ ±10%.(at 25°C).