Shut-Off Valve With Service Port; Liquid Refrigerant Solenoid Valve; Typical Malfunctions - PREVOST H3-41 Maintenance Manual

4.9 SHUT-OFF VALVE WITH SERVICE
PORT
This shutoff valve (FIGURE 51) is located in the
condenser compartment. It is used to isolate one
section of the refrigerant circuit. The service port
is equipped with a Schrader valve.
FIGURE 51: REFRIGERANT CIRCUIT SHUT-OFF VALVE
FIGURE 52: REFRIGERANT CIRCUIT SHUT-OFF VALVE
4.10 LIQUID REFRIGERANT SOLENOID
VALVE
The flow of liquid refrigerant to the driver's unit
evaporator, passengers' unit evaporator (main
evaporator) and overhead
evaporator is controlled by one NC (normally
closed) solenoid valve on each circuit, for a total
of three solenoid valves.
The driver's unit solenoid valve is located on the
ceiling of the spare wheel compartment (
) and is accessible through the reclining
53
bumper.
Two identical NC (normally closed) refrigerant
solenoid valves are found in the condenser
compartment (FIGURE 54). One is used to
control flow of refrigerant to the overhead
compartments evaporator while the other is
SECTION 22: HEATING AND AIR CONDITIONING
used to control flow to the driver's and
passenger's main evaporators.
On H3 VIP, one identical refrigerant solenoid
valve is used on the small HVAC system
auxiliary unit (Figure 9).
FIGURE 53: DRIVER'S UNIT LIQUID SOLENOID VALVE
FIGURE 54: LIQUID REFRIGERANT SOLENOID VALVES
IN CONDENSER COMPARTMENT (X-SERIES)
compartments
4.10.1
Faulty control circuit: Check the electric system
by energizing the solenoid with 24-V DC.
FIGURE
metallic clicking noise indicates that the solenoid
is operating. Absence of clicking indicates a loss
of power or a defective solenoid.
open breaker, open-circuited or grounded coil,
broken lead wires.
Burned-out coil: Check for open-circuited coil.
Replace coil if necessary.
PA1621 Maintenance Manual All Series | Revised February 2019

Typical Malfunctions

A
Check for
37