Fujitsu AUXB04GALH Service Manual page 143

Trouble shooting 65
OUTDOOR UNIT Error Method:
Low Pressure Abnormal
Detective Actuators:
Suction pressure sensor
Forecast of Cause : 1. 3-way valve not opened 2. Outdoor unit ambient temperature too low
3. Outdoor unit fan operation defective, foreign matter at heat exchanger
4. EEV defective, strainer clogged 5. Solenoid valve defective
6. Low pressure sensor characteristics defective 7. Insufficient refrigerant
<Cooling 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.
OK
Check Point 2 : Check the indoor unit EEV,
strainer clogging
Indoor unit EEV operation check
Strainer not clogged?
OK
Check Point 3: Check the suction pressure sensor
Suction pressure sensor characteristics check
* For the characteristics of the suction pressure sensor, refer to "Service
Parts Information 15".
OK
Check Point 4 : Check the refrigerant amount
Leak check
E. A5. 1 Indicate or Display:
Outdoor Unit : E. A5. 1
Indoor Unit
Error Code
Detective details:
"Protection stop by "suction pressure
for 10 minutes" or "suction pressure
of any compressor"" was generated 5 times within 3 hours
04-73
: Operation LED 9 times Flash, Timer LED 15 Times Flash,
Filter LED Continuous Flash.
: A5
0.10MPa continued
0.05MPa during operation
<Heating 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 ambient temperature
Outdoor ambient temperature lower than operating range?
OK
Check Point 3 : Check the outdoor unit fan operation,
heat exchanger
No foreign matter in air passage?
Heat exchange fins clogged
Fan rotates?
Outdoor unit fan motor check
OK
Check Point 4 : Check the outdoor unit EEV, strainer clogging
Outdoor unit EEV1 operation check
Strainer not clogged?
Refer to "Service Parts Information 9".
OK