PREVOST X3-45 COMMUTER User Manual

SECTION 22: HEATING AND AIR CONDITIONING
DOB 1300-1556 | X3-45 Commuter PA-1648 Maintenance Manual First release Oct 2020
43
conditioning will remove moisture in air
and prevent fogging up of the windows).
NOTE
Upon starting if the outside temperature is
above 32°F (0°C) and then drops below 32°F
(0°C), the compressor will keep running
down to a temperature of 15°F (-
9°C) to
prevent fogging up of the windows.
The driver’s HVAC unit piping is paralleled with
the passengers’ HVAC unit piping. Both sections
use the same refrigerant and hot water, and are
linked to the same condenser and compressor,
even if they are individually controlled. In order
for the driver to have air conditioning, the
passenger air conditioning system must be
operating (A/C compressor must be operating).
NOTE
The driver's and passengers’ HVAC unit turn
on automatically at starting of the engine
(multiplex receives the “engine running”
signal) when the multiplex
system receives
an “engine running” signal.
NOTE
To perform a test of the driver's section
windshield defroster, it is possible to run the
system without running the engine.
The following table can be used for
troubleshooting the following temperature
sensors:
NOTE
The driver’s area air temperature sensor is
located
below the dashboard, just ahead of
the driver's right knee.
1) Driver’s area temperature sensor (SE21);
2) Passengers’ area temperature sensor (SE25);
3) Outside air temperature sensor (SE20).
The table values are for unloaded, disconnected
temperature sensor (thermistor) probed at the
temperature sensor connector pins.
TEMPERATURE SENSOR
Temp °C Temp °F Resistance Ohms
-40 -40 100865
-35
-31
72437
-30
-22
52594
-25
-13
38583
-20
-4
28582
-15
5
21371
-10
14
16120
-5
23
12261
0
32
9399
5
41
7263
10 50 5658
15
59
4441
20
68
3511
25
77
2795
30
86
2240
35
95
1806
40
104
1465
45
113
1195
50
122
980
55
131
808
60 140 670
6.5 PASSENGERS’ SECTION OPERATION
The passengers’ section has a preset
temperature of 68°F (20°C).
FIGURE 46: HVAC SYSTEM CONTROL UNIT
Temperature control is provided in conjunction with
a thermistor sensor inside the return air box,
located on the mid L.H. side of the vehicle under
the seats (Figure 47).

PREVOST X3-45 COMMUTER Specifications

General

Engine	Volvo D13
Transmission	Allison B500
Fuel Type	Diesel
Length	45 ft (13.7 m)
Width	102 in (2.6 m)
Horsepower	500 hp
GVWR	54, 000 lbs
Height	141 in