High Pressure Abnormal - Fujitsu Airstage V-II Service Manual

Trouble shooting 56
OUTDOOR UNIT Error Method:

High Pressure Abnormal

Detective Actuators:
Judgment from value sensed by discharge
pressure sensor
Forecast of Cause : 1. 3-way valve not opened 2. Outdoor unit fan operation defective, foreign matter at heat
exchanger, excessive ambient temperature rise 3. Check valve clogged
4. EEV defective, strainer clogged 5. Solenoid valve defective
6. Discharge pressure sensor defective 7. Refrigerant overcharged
<Cooling operation>
Check Point 1 : Check if 3-way valve(liquid side) is open.
If the 3-way valve(liquid side) was closed, open the
3-way valve(liquid side) and check operation.
OK
Check Point 2 : Check the outdoor unit fan operation,
heat exchanger, ambient temperature
No foreign matter in air passage?
Heat exchange fins clogged
Outdoor unit fan motor check
Ambient temperature not raised by effect of other heat sources?
Discharged air not sucked in?
OK
Check Point 3 : Check the check valve
Check if check valve (parallel with EEV1) not clogged.
OK
Check Point 5 : Check the solenoid valve (SV1, SV2)
Solenoid valve operation check
Refer to "Service Parts Information 17".
OK
Check Point 6 :Check the discharge pressure sensor
Discharge pressure sensor characteristics check
* For the characteristics of the discharge pressure sensor, refer to "Service
Parts Information 20".
OK
Check Point 7 : Check the refrigerant amount
Refrigerant charged amount check
Indicate or Display:
Outdoor Unit : E. A4. 1
Indoor Unit : Operation LED 9 times Flash, Timer LED 15 Times Flash,
Filter LED Continuous Flash.
Error Code : A4
Detective details:
"Protection stop by "discharge pressure
compressor"" generated 3 times within 60 minutes
<Heating operation>
Check Point 1 : Check if 3-way valve(gas side) is open.
If the 3-way valve(gas side) was closed, open the
3-way valve(gas side) and check operation.
Check Point 4 : Check the EEV, strainer (indoor unit)
EEV operation check
Check of strainers before and after EEV
Refer to "Service Parts Information 14, 15, 16".
OK
04-64
4.00MPa during operation of any
OK