High Pressure Protection 2 - Fujitsu Airstage V-II Service Manual

Trouble shooting 58
OUTDOOR UNIT Error Method:

HIgh Pressure Protection 2

Detective Actuators:
High pressure switch 2
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. High pressure switch 2 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 3-1 : Check valve check
Check if check valve (parallel with EEV1) not clogged.
OK
Check Point 3-2 : Check valve check
Check if check valve (oilseparetor (out) of compressor 2)
is not clogged.
OK
Check Point 5 : Solenoid valve (SV1, SV2) check
Solenoid valve operation check
Refer to "Service Parts Information 17".
OK
Check Point 6 : High pressure switch 2 check
High pressure switch 2 characteristics check
* For the characteristics of the high pressure switch 2, refer to the "Service
Parts Information 21".
OK
Check Point 7 : Refrigerant amount check
Refrigerant charged amount check
Indicate or Display:
Outdoor Unit : E. A4. 3
Indoor Unit : Operation LED 9 times Flash, Timer LED 15 Times Flash,
Filter LED Continuous Flash.
Error Code : A4
Detective details:
"Protection stop by "high pressure switch 2 operated during compressor 2
operation"" 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 (indoorunit)
EEV operation check
Check of strainers before and after EEV
Refer to "Service Parts Information 14, 15, 16".
04-66
OK
OK