Fujitsu Comfort Series Service Manual page 40

Troubleshooting 14
OUTDOOR UNIT Error Method:
Pressure switch error
Pressure sensor error
Detective Actuators:
High pressure switch
Pressure sensor
Forecast of Cause :
1. Connector disconnection, open
2. Characteristics failure
3. Main PCB failure
Pressure switch
Check Point 1 : Check the pressure switch connection state
Connector and wiring connection state check
Cable open check
OK
Check Point 2 : Check the high pressure switch characteristics
Switch characteristics check
* For the characteristics of high pressure switch, refer to below.
OK
Check Point 3 : Replace Main PCB
Change Main PCB, and execute the check operation again.
Type of contact
C
Pressure
Characteristics of pressure switch (P20)
Contact : Short
Contact : Open
H
Pressure switch
4.2 0.1MPa
Open
Short 3.2 0.15MPa
Indicate or Display:
Green 8 flash / Red 6 flash
Detective details:
When the power was turned on, "high pressure switch : open" was detected.
Pressure sensor short or open detected.
Pressure sensor
Check Point 1 : Check the pressure sensor connection state
Connector and wiring connection state check
Cable open check
Check Point 2 : Check the pressure sensor
Pressure sensor characteristics check
(Disconnect the pressure sensor from the PCB and check.)
* For the pressure sensor characteristics, refer to the "Service
Parts information 6".
Check Point 3 : Check voltage of Main PCB (DC5.0V)
Main PCB (P21:1-4) voltage value = 5.0V
Remove the pressure sensor from Main PCB,
check the valtage.
03-15
Outdoor unit : No indication
OK
OK
P21 Pressure sensor (P21:1-4)
1 2 3 4
WHITE
1 2 3
If the voltage do not appear,
replace Main PCB, and execute
the check operation again.
P S Pressure sensor