Subaru 2009 IMPREZA Service Manual page 2720

HVAC SYSTEM (HEATER, VENTILATOR AND A/C)
20.Pressure Switch (Triple Pressure Switch)
A: INSPECTION
1) Connect the manifold gauge to the service valve on the high-pressure side.
2) Disconnect the pressure switch harness connector.
3) Start the air conditioner, and check the operating pressure of switch by turning the compressor (magnet
clutch) to ON/OFF. Operation of each switch is as follows.
(1)
(2)
(10)
(9)
(3)
(11)
(13)
(14)
(1) High pressure switch
(2) Middle pressure switch
(3) Low pressure switch
(4) 2,350 200 kPa
2
(24.00 2.04 kg/cm ,
340.7 29.0 psi)
(5) 2,940 200 kPa
2
(29.98 2.04 kg/cm ,
426.3 29.0 psi)
NOTE:
• High pressure switch turns the compressor (magnet clutch) to OFF when the refrigerant pressure be-
comes extremely high to prevent the evaporator, air conditioner piping and expansion valve from getting
damaged or frozen, etc.
• Middle pressure switch effectively controls the radiator fan output by judging high load/low load in normal
range.
• If the refrigerant pressure is abnormally low, the low pressure switch determines that there is insufficient
refrigerant, and turns the compressor (magnetic clutch) OFF since there is a possibility that the compressor
will seize if it is continued to run.
Pressure Switch (Triple Pressure Switch)
(7)
(11)
(8)
(6) 1,770 100 kPa
(18.05 1.02 kg/cm
256.65 14.5 psi)
(7) 1,470 120 kPa
(14.99 1.22 kg/cm
213.15 17.4 psi)
(8) 206 30 kPa
(2.10 0.31 kg/cm
(10)
(6)
(12)
2
,
2
,
2
, 29.9 4.3 psi)
AC-40
(10)
(5)
(4)
(11)
(15)
(9) 177 25 kPa
2
(1.80 0.25 kg/cm , 25.7 3.6 psi)
(10) ON
(11) OFF
(12) Operative range of compressor
(13) Inoperative range of compressor
(14) Low pressure
(15) High pressure
(13)
AC-01433