Panasonic CS-E24MKDS / CU-E24MKD / CS-E28MKDS / CU-E28MKD Service Manual ▷ View online
89
15.5.27. F96 (IPM Overheating)
Malfunction Decision Conditions
During operating of cooling and heating, when IPM temperature data (100
C) is detected by the IPM temperature sensor.
Multi Models Only
• Compressor Overheating: During operation of cooling and heating, when the compressor OL is activated.
• Heat Sink Overheating: During operation of cooling and heating, when heat sink temperature data (90°C) is detected by the heat
• Heat Sink Overheating: During operation of cooling and heating, when heat sink temperature data (90°C) is detected by the heat
sink temperature sensor.
Malfunction Caused
• IPM overheats due to short circuit of hot discharge air flow.
• IPM overheats due to defective of outdoor fan motor.
• IPM overheats due to defective of internal circuitry of IPM.
• IPM overheats due to defective IPM temperature sensor.
• IPM overheats due to defective of outdoor fan motor.
• IPM overheats due to defective of internal circuitry of IPM.
• IPM overheats due to defective IPM temperature sensor.
Multi Models Only
• Compressor OL connector poor contact.
• Compressor OL faulty.
• Compressor OL faulty.
Troubleshooting
90
15.5.28. F97 (Compressor Overheating)
Malfunction Decision Conditions
During operation of cooling and heating, when compressor tank temperature data (112
C) is detected by the compressor tank
temperature sensor.
Malfunction Caused
• Faulty compressor tank temperature sensor
• 2/3 way valve closed
• Refrigerant shortage (refrigerant leakage)
• Faulty outdoor unit PCB
• Faulty compressor
• 2/3 way valve closed
• Refrigerant shortage (refrigerant leakage)
• Faulty outdoor unit PCB
• Faulty compressor
Troubleshooting
91
15.5.29. F98 (Input Over Current Detection)
Malfunction Decision Conditions
During operation of cooling and heating, when an input over-current (X value in Total Running Current Control) is detected by
checking the input current value being detected by current transforme r (CT) with the compressor running.
checking the input current value being detected by current transforme r (CT) with the compressor running.
Malfunction Caused
• Excessive refrigerant.
• Faulty outdoor unit PCB.
• Faulty outdoor unit PCB.
Troubleshooting
92
15.5.30. F99 (Output Over Current Detection)
Malfunction Decision Conditions
During operation of cooling and heating, when an output over-current (DC peak current value at IPM Prevention Control) is
detected by checking the current that flows in the inverter DC peak sensing circuitry.
detected by checking the current that flows in the inverter DC peak sensing circuitry.
Malfunction Caused
• Faulty outdoor unit PCB
• Faulty compressor
• Faulty compressor
Troubleshooting
• Checking the power transistor
• Never touch any live parts for at least 10 minutes after turning off the circuit breaker.
• If unavoidable necessary to touch a live part, make sure the power transistor’s supply voltage is below 50V using the tester.
• For the UVW, make measurement at the Faston terminal on the board of the relay connector.
• Never touch any live parts for at least 10 minutes after turning off the circuit breaker.
• If unavoidable necessary to touch a live part, make sure the power transistor’s supply voltage is below 50V using the tester.
• For the UVW, make measurement at the Faston terminal on the board of the relay connector.
Tester’s negative terminal
Power transistor (+)
UVW
Power transistor (-)
UVW
Tester’s positive terminal
UVW
Power transistor (+)
UVW
Power transistor (-)
Normal resistance
Several k
: to several M:
Abnormal resistance
0 or
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