Subaru SVX 1992 Manual page 948

4-7 IM4041
AUTOMATIC AIR CONDITIONING SYSTEM
4 . TRINARY SWITCH
The trinary switch is located in the high-pressure line of the
refrigeration cycle. It consists of a diaphragm which
receives pressure, diaphragm springs, pin and contact
points . Two types of contact points are used . One type
activates when the internal pressure is low or when it is too
high while the other type controls the operation of the con-
denser fan.
1) Prevention of operation when there is no gases in the
line due to absence of refrigerant - (during low-pressure
operation) .
2) Protection of refrigeration cycle from abnormal refriger-
ant pressure rise - (during high-pressure operation) .
3) 3-speed control to provide a quiet condenser fan oper-
ation - (during intermediate-pressure operation) .
118±20 (1 .2±0 .2, 17 .1±2 .8) 2,648±196 (27±2.0, 384±28)
ON---
Diaphragm
Spring
Contact point
OFF
127±29 (1 .3±0 .3,
1,471
+196 ( 15 +2 .0
213
+28
18±4)
-98 ` -1 .0 -14
Spring (1-/
`Shaft
1,275±147 (13±1 .5, 185±21)
Spring ~ ~7
`Contact point - --- ON
OFF
Unit : kPa (kg/cm', psi)
1,569±127 (16±1 .3, 228±18)
C4-1016
Fig. 9
4) High-low pressure switch
(1) When pressure is abnormally low
[P < Approx . 118 kPa (1 .2 kg /cm2, 17 psi)]
The tension of springs 10, (2 and (3 is greater than
the refrigerant pressure, and the contact A opens to
turn the switch OFF.
(2) When pressure is normal .
[Approx. 127 kPa (1 .3 kg /cm2, 18 psi) < P < Approx .
2,648 kPa (27 kg/cmz, 384 psi)]
When the refrigerant pressure rises above 127 kPa (1 .3
kg/cm2, 18 psi), the spring 11) reverses, and the contact
closes to turn the switch ON .
zing (I)
Contact point © (OFF)
Refrigerant
pressure
Contact point (A (ON)
C4-3901
Fig . 10
Fig. 11
6