Small Hvac System; System Configuration H-Series; System Configuration X3 Series - PREVOST H3-41 Maintenance Manual

4. Mid seat the compressor suction and
discharge shutoff valves.
5. Using connector C24 and C44, energize
and open the liquid solenoid valves (driver's
unit, passengers'
compartment units). To do so, uncap and
connect male and
housings of C24
passengers' area (located on the HVAC
module in evaporator compartment) or C44
for the driver's area (located on the ceiling
of the spare wheel compartment).
6. Start the vacuum pump.
7. The pressure will drop to approximately 29
in-HG gauge vacuum.
8. Evacuate to a system pressure of 500
micron.
9. Shut down the vacuum pump. Validate that
the vacuum holds. If the pressure rises, it
indicates a leak.
10. Backseat the compressor shutoff valves by
turning "out" all the way.
11. Remove the hoses.
12. Reinstall the red and blue caps at the
suction and discharge shutoff valves service
ports.
13. Disconnect C24 & C44.
7.

SMALL HVAC SYSTEM

The small HVAC system is found only on
motorhomes and has a much lower heating and
air cooling capacity than the central system
because it is designed to provide air conditioning
to the driver's area only.
7.1

SYSTEM CONFIGURATION H-SERIES

On H3-series vehicles, the compressor is
installed away from the engine and uses a
pneumatic belt tensioner.
unit and overhead
female connector
together for the
PA1621 Maintenance Manual All Series | Revised February 2019
SECTION 22: HEATING AND AIR CONDITIONING
FIGURE 84: BELT LAYOUT WITH SMALL A/C
COMPRESSOR h3-45 VIP
In this configuration, the condenser is installed
over the radiator and benefits from the existing
airflow in this location. All the associated service
ports and service valves are close to the
compressor.
7.2 SYSTEM CONFIGURATION X3
SERIES
On X-series vehicles, the compressor is installed
on a support attached to the central A/C
pedestal on the engine and uses an automatic
belt tensioner.
FIGURE 85 X3 SERIES SMALL A/C COMPRESSOR
In this configuration, the condenser is located in
the 4th luggage compartment it has its own
electric fan to provide the required cooling. All
the associated service ports and service valves
are on top of the condenser frame.
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