Pressure Switch - wsm M8540NARROW Workshop Manual

M8540Narrow, M9540Narrow, WSM

(7) Pressure Switch

Pressure Switch
1) HI Pressure Side
1. Connect the manifold gauge (5) to compressor as following
procedure.
Close the HI and LO pressure valves (3), (4) of manifold gauge
tightly, and connect the charging hoses (2), (1) (red and blue) to
the respective compressor service valves. (Refer to "[1]
HANDLING OF SERVICE TOOLS" at "10. CABIN" section.)
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
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 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.
Factory
Setting pressure specifica-
tion
2) LO Pressure Side
1. Disconnect 2P connector of pressure switch (6).
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)
Factory
Setting pressure specifica-
tion
• The resistance of pressure switch is 0 ohm in normal condition,
but it becomes infinity if the pressure is out of factory spec..
Because the pressure switch starts to work.
(1) Charging Hose (Blue)
(2) Charging Hose (Red)
(3) HI (High Pressure Side) Charging
Valve
N10-S8
-1
(rpm). Turn on
More than
Pressure approx. 3.14 MPa
2
switch OFF 32 kgf/cm
455 psi
Less than
Pressure approx. 0.196 MPa
2
switch OFF 2.0 kgf/cm
28.4 psi
(4) LO (Low Pressure Side) Charging
Valve
(5) Manifold Gauge
(6) Pressure Switch
9Y1210236CAS0014US0
CABIN
KiSC issued 07, 2013 A