Panasonic CS-E10JD3EA / U-E10HBEA / CS-E15JD3EA / CU-E15HBEA / CS-E18JD3EA / CU-E18HBEA Service Manual ▷ View online
73
15.5.14. H99 (Indoor Freeze Prevention Protection: Cooling or Soft Dry)
Error code will not display (no TIMER LED blinking) but store in EEPROM
Malfunction Decision Conditions
• Freeze prevention control takes place (when indoor pipe temperature is lower than 2
°C).
Malfunction Caused
• Air short circuit.
• Clogged air filter of the indoor unit.
• Dust accumulation on the indoor unit heat exchanger.
• 2/3 way valve closed.
• Faulty indoor fan motor.
• Refrigerant shortage (refrigerant leakage).
• Detection error due to faulty indoor pipe temperature sensor.
• Detection error due to faulty indoor unit PCB.
• Clogged air filter of the indoor unit.
• Dust accumulation on the indoor unit heat exchanger.
• 2/3 way valve closed.
• Faulty indoor fan motor.
• Refrigerant shortage (refrigerant leakage).
• Detection error due to faulty indoor pipe temperature sensor.
• Detection error due to faulty indoor unit PCB.
Troubleshooting
74
15.5.15. F11 (4-way valve Abnormality)
Malfunction Decision Conditions
• When heating operation, when indoor pipe temperature is below 10
°C.
• When cooling operation, when indoor pipe temperature is above 45
°C.
Malfunction Caused
• Connector in poor contact.
• Faulty sensor.
• Faulty outdoor unit PCB.
• 4-way valve defective.
• Faulty sensor.
• Faulty outdoor unit PCB.
• 4-way valve defective.
Troubleshooting
75
15.5.16. F90 (Power Factor Correction Protection)
Malfunction Decision Conditions
• During startup and operation of cooling and heating, when Power Factor Correction (PFC) protection circuitry at the outdoor unit
main PCB senses abnormal high DC voltage level.
Malfunction Caused
• DC voltage peak due to power supply surge.
• DC voltage peak due to compressor windings not uniform.
• Faulty outdoor PCB.
• DC voltage peak due to compressor windings not uniform.
• Faulty outdoor PCB.
Troubleshooting
76
15.5.17. F91 (Refrigeration Cycle Abnormality)
Malfunction Decision Conditions
• During cooling, compressor frequency = Fcmax.
• During heating, compressor frequency > Fhrated.
• During cooling and heating operation, running current: 0.65A < I < 1.65A.
• During cooling, indoor intake - indoor pipe < 4
• During heating, compressor frequency > Fhrated.
• During cooling and heating operation, running current: 0.65A < I < 1.65A.
• During cooling, indoor intake - indoor pipe < 4
°C.
• During heating, indoor pipe - indoor intake < 5
°C.
Multi Models Only
- Gas shortage detection 1: A gas shortage is detected by checking the CT-detected input current value and the compressor
running frequency. During startup and operating of cooling and heating, input current < 8.78/256 (A/Hz)
× compressor
running frequency + 0.25.
- Gas shortage detection 2: A gas shortage is detected by checking the difference between indoor pipe temperature and indoor
intake air temperature during cooling and heating.
Malfunction Caused
• Refrigerant shortage (refrigerant leakage).
• Poor compression performance of compressor.
• 2/3 way valve closed.
• Detection error due to faulty indoor intake air or indoor pipe temperature sensors.
• Poor compression performance of compressor.
• 2/3 way valve closed.
• Detection error due to faulty indoor intake air or indoor pipe temperature sensors.
Troubleshooting
Click on the first or last page to see other CS-E10JD3EA / U-E10HBEA / CS-E15JD3EA / CU-E15HBEA / CS-E18JD3EA / CU-E18HBEA service manuals if exist.