PREVOST X3-45 Multiplex, Maintenance Manual

Page: 160 / 1422

Section 06: ELECTRICAL
PA1562
24
In test mode, with the parking brake applied and
the passenger set point set to a value higher
than 64°F (18°C), the circulator pump is not set
to OFF as it would normally do when the outside
temperature gets above 50°F (10°C). This
feature allows verification of the pump when
inside a garage. This is also useful when
working on the heating system to remove air
pockets trapped in the system.
When performing an A/C cooling test and having
the water pump shut off in switch/sensor test
mode is required, just set the passenger set
point temperature to the minimum 64°F (18°C)
to shut off the pump.
4.5 TEST MODE FOR ELECTRIC MOTORS
The test mode allows testing the motors and
electric contactors without the need to have the
engine running. Note that while in test mode, the
engine cannot be started.
Prerequisite conditions for the motor test mode:
A. The battery charger must be connected to a
110-120 volt power supply. If not, the test
will be interrupted when the voltage drops
below 24.4 volts,
B. Engine not running,
C. Parking brake applied,
DANGER
Before starting the test sequence, make sure
nobody is working in the evaporator or
condenser compartment.
NOTE
A delay of 15 seconds during which the back-
up alarm will sound is introduced prior the test
start to advise people that may be working on
the vehicle.
To enter this mode:
o
Activate the dashboard Telltale Light Test
switch 3 times within 4 seconds;
o
Push the ON/OFF button on the driver's side
HVAC control unit 5 times (that makes 3
transitions from OFF to ON),
o
A beep can be heard indicating the motor
test mode has started.
Using the test mode:
o
During the entire test, the telltale panel
audible alarm gives a signal each second to
remind that the motor test mode is underway.
4.5.1 Test Sequence
Go to the condenser compartment.
o
The condenser fans runs for 3 seconds at
speed 1.
o
1 second delay.
o
Speed 2 activates for 3 seconds.
o
3 seconds delay.
o
Passenger's unit refrigerant solenoid valve
activates 3 times at 1 second interval.
Then 5 beeps can be heard from the back-up
alarm to indicate to go to the engine
compartment (15 SECONDS DELAY).
In the engine compartment, the sequence is
as follows:
o
Toilet fan motor runs for 3 seconds.
o
1 second delay.
o
A/C compressor clutch activates 3 times at 1
second interval.
o
1 second delay.
o
Left compressor unloader activates 3 times
at 1 second interval.
o
1 second delay.
o
Right compressor unloader activates 3 times
at 1 second interval.
5 beeps from the back-up alarm indicate to
go to the engine radiator fan (5 SECONDS
DELAY).
o
Fan clutch is disengaged for 3 seconds (fan
can be turned freely by hand).
o
Fan clutch engages for 3 seconds in speed 1
(fan can be turned by hand but with a certain
resistance).
o
3 seconds delay.
o
Fan clutch engages for 3 seconds in speed 2
(cannot be turned but hand).
o
10 seconds delay.