90
Diagnosis
display
Abnormality /
Protection control
Abnormality
Judgment
Protection
Operation
Problem Check
location
H98
Indoor high pressure
protection
— —
Indoor high pressure
protection (Heating)
Check indoor heat exchanger
Air filter dirty
Air circulation short circuit
H99
Indoor operating unit
freeze protection
— —
Indoor freeze protection
(Cooling)
Check indoor heat exchanger
Air filter dirty
Air circulation short circuit
F11
4-way valve
switching
abnormality
4 times happen
within 30 minutes
—
4-way valve switching
abnormal
4-way valve
Lead wire and connector
F17
Indoor standby units
freezing abnormality
3 times happen
within 40 minutes
—
Wrong wiring and
connecting pipe, expansion
valve leakage, indoor heat
exchanger sensor open
circuit
Check indoor/outdoor
connection wire and pipe
Indoor heat exchanger sensor
lead wire and connector
Expansion valve lead wire and
connector
F90
Power factor
correction
(PFC) circuit
protection
4 times happen
within 10 minutes
—
Power factor correction
circuit abnormal
Outdoor PCB faulty
F91
Refrigeration cycle
abnormality
2 times happen
within 20 minutes
—
Refrigeration cycle
abnormal
Insufficient refrigerant or valve
close
F93
Compressor
abnormal revolution
4 times happen
within 20 minutes
—
Compressor abnormal
revolution
Power transistor module faulty
or compressor lock
F94
Compressor
discharge overshoot
protection
4 times happen
within 30 minutes
—
Compressor discharge
pressure overshoot
Check refrigeration system
F95
Outdoor cooling high
pressure protection
4 times happen
within 20 minutes
—
Cooling high pressure
protection
Check refrigeration system
Outdoor air circuit
F96
Power transistor
module overheating
protection
4 times happen
within 30 minutes
—
Power transistor module
overheat
PCB faulty
Outdoor air circuit (fan motor)
F97
Compressor
overheating
protection
3 times happen
within 30 minutes
— Compressor
overheat
Insufficient refrigerant
F98
Total running current
protection
3 times happen
within 20 minutes
— Total
current
protection
Check refrigeration system
Power source or compressor
lock
F99
Outdoor direct
current (DC) peak
detection
Continuous
happen for 7 times
—
Power transistor module
current protection
Power transistor module faulty
or compressor lock