Kubota B1830, Workshop Manual

Page: 530 / 548

CABIN B1830,B2230,B2530,B3030, WSM
10-S25
Pressure Switch
1) HI Pressure Side
1. Connect the manifold gauge (6) to compressor as following
procedure.
Close the
HI and LO pressure valves (5), (7) of manifold gauge
tightly, and connect the charging hoses (red and blue) (1), (4) to
the respective compressor service valves.
NOTE
• Be sure to drive out the air in the charging hoses at the
manifold gauge connection end by utilizing the refrigerant
pressure in the refrigerant cycle.
2. Start the engine and set at approx. 1500 min
-1
(rpm). Turn on
the A/C switch, then set the blower switch to HI position.
3. Raise pressure on the HI pressure side of the refrigerant cycle
by covering the condenser front with a corrugated carboard, and
the pressure switch (8) is activated and the compressor
magnetic clutch is turned off. At this time, read the
HI pressure
gauge of the manifold gauge. If this pressure reading differs
largely with the setting pressure, replace the pressure switch
with a new one.
2) LO Pressure Side
1. Disconnect 2P connector of pressure switch.
2. Measure the resistance with an ohmmeter across the connector
terminals.
3. If 0 ohm is not indicated at normal condition, there is no
refrigerant in the refrigerating cycle because gas leaks or
pressure switch is defective.
(Reference)
• The resistance of pressure switch is 0 ohm in normal running,
but is becomes infinity if the pressure is abnormal (out of factory
spec.). Because the pressure switch starts to work.
9Y1210003CAS0044US0
Setting pressure
Factory
specifica-
tion Pressure
switch
OFF
More than Approx.
2.94 MPa
30 kgf/cm
2
426 psi
Setting pressure
Factory
specifica-
tion Pressure
switch
OFF
Less than Approx.
0.196 MPa
2.0 kgf/cm
2
28.4 psi
(1) Charging Hose (Red)
(2)
HI (High Pressure Side) Charging
Valve
(3) LO (Low Pressure Side) Charging
Valve
(4) Charging Hose (Blue)
(5)
HI Pressure Valve
(6) Manifold Gauge
(7)
LO Pressure Valve
(8) Pressure Switch
KiSC issued 05, 2012 A