Periodic Maintenance And Servicing; System Operation - R/V & G-Van; Functional Test - R/V & G-Van - GMC G Service Manual

IB -4 AIR CONDITIONING
C
A. Inlet
B. Outlet
C. Refrigerant Vapor Outlet
15. Baffle
16. Internal Tube
17. Desiccant Bag
18. Filter
19. Oil Bleed Hole
Figure 2 — Accumulator R/V & G-Van
Flow from the accumulator to the compressor consists of
vapor, entrained liquid and liquid flow through the oil bleed
hole.
A bag of desiccant (dehydrating agent), located in the
accumulator, collects moisture.
The accumulator with the CCOT system has no sight
glass and is not serviceable.
ORIFICE (EXPANSION TUBE) R/V & G-VAN
Pressure differences and sub-cooling determines
expansion tube flow. The orifice is located in the evaporator
inlet line (figure 3).
F. Inlet
G. Outlet (To Evaporator)
H. Dent On Tube (Retains the Expansion Tube)
20. Outlet Screen
21. Expansion Tube
Figure 3 — Orifice (Expansion Tube)
CYCLING PRESSURE SWITCH
This switch controls evaporator temperature. It cycles
the compressor clutch off when the evaporator temperature
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22. Inlet Screen
23. Seal B-07208
gets too low. It cycles the compressor back on after evapo­
rator temperature has increased (figure 4).
Figure 4 — Cycling Pressure Switch
The cycling pressure switch provides inherent compres­
sor protection so a separate low pressure switch is not
necessary. The switch also acts as an ambient switch since
at ambient freezing temperatures it will not allow the com­
pressor to engage. Adjusting the setscrew one-half turn left
or right will raise or lower the settings 20.7 kPa (3 psi).
Cycling Pressure Switch Setting (Accumulator
Readings)
Compressor Cut-Out Pressure Range: 71-81 kPa
(21-24 psi)
Compressor Cut-In Pressure Range: 145.2-165.4 kPa
(43-49 psi)
PERIODIC MAINTENANCE
AND SERVICING
Inspect the system once a year, preferably in the spring
before warm weather.
Check refrigerant lines for leaks.
Check refrigerant charge; evaluate and recharge as
necessary.
SYSTEM OPERATION — R/V &
G-VAN
For information on selector switch, select valve and fan
switch operating characteristics, refer to figure 5.
FUNCTIONAL TEST — R/V &
G-VAN
To check the operation of the control assembly, perform
each of these tests as one complete operation. Refer to
figures and 7.
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