Subaru 2009 IMPREZA, Service Manual

Page: 2720 / 3619

AC-40
Pressure Switch (Triple Pressure Switch)
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.
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.
(1) High pressure switch (6) 1,770
r
100 kPa
(18.05
r
1.02 kg/cm
2
,
256.65
r
14.5 psi)
(9) 177
r
25 kPa
(1.80
r
0.25 kg/cm
2
, 25.7
r
3.6 psi)
(2) Middle pressure switch
(3) Low pressure switch (10) ON
(4) 2,350
r
200 kPa
(24.00
r
2.04 kg/cm
2
,
340.7
r
29.0 psi)
(7) 1,470
r
120 kPa
(14.99
r
1.22 kg/cm
2
,
213.15
r
17.4 psi)
(11) OFF
(12) Operative range of compressor
(13) Inoperative range of compressor
(5) 2,940
r
200 kPa
(29.98
r
2.04 kg/cm
2
,
426.3
r
29.0 psi)
(8) 206
r
30 kPa
(2.10
r
0.31 kg/cm
2
, 29.9
r
4.3 psi)
(14) Low pressure
(15) High pressure
AC-01433
(1)
(9)
(2)
(3)
(8)
(4)
(5)
(6) (7)
(11)
(10)
(10)
(11)
(11)
(10)
(12)
(13)
(13)
(14)
(15)