Preheating Systems; Main Breakers - PREVOST Le Mirage XL Owner's Manual

Preheating Systems (optional)
Espar (Eberspächer):
Description of operations
This Auxiliary Preheating System is used for
preheating and retaining the heat of water-
cooled engines. It can be used before starting
the engine to ease its starting and to provide
immediate inside heat upon operation of the
heating system. It can also be used with engine
running to maintain coolant heat and maintain
the set temperature inside vehicle.
The heater operates independently of the
vehicle engine. It is connected to the cooling
and heating circuits, the fuel system and the
electrical system of the vehicle.
The pilot lamp turns on when the heater is
switched on. Combustion air flows in to flush
out the combustion chamber, and the water
circulation pump is put into operation. The fuel
metering pump conveys fuel in precise doses to
the combustion chamber, where fuel and
combustion air form a combustible mixture
which is ignited by the glow plug.
Once the flame sensor has signaled to the
control unit that combustion has taken place
correctly, the glow-spark plug and ignition coil
are switched off.
The hot combustion gases are diverted at the
end of the flame pipe, then pass through the
indirect heating surfaces of the heat exchanger
and transmit their heat to the water passing
through the heat exchanger.
The heat is thermostatically controlled, and
operates intermittently, i.e. the switched-on
times of the burner vary depending on the heat
requirement. The water temperature depends
on the setting of the built-in water thermostat.
The water circulation pump remains in operation
as long as the heater is operating - even in the
regulation intervals and during the delayed
cutout of the switched-off heater. The pump can
also be operated independently of the heater by
means of an appropriate circuit. The heater can
be switched on at any time, i.e. during the
delayed cutout period too. Ignition takes place
once this delay time is over.
When the heater is switched off, the fuel supply
is interrupted. The flame goes out, and at the
same time a delayed cutout of some 2.5 minutes
begins. The combustion air still flowing flushes
STARTING AND STOPPING PROCEDURES
the remaining combustion gases out of the
chamber and cools off the hot parts on the
exhaust side of the heat exchanger, while the
water circulation pump still running transmits the
heat present in the heat exchanger, thus
preventing local overheats. Once the delayed
cutout time is over, both the combustion air
blower and the water circulation pump switch off
automatically. A cutout will take place in case of
any failure of the preheater.
Webasto:
Description of operations
Switch on the heater, the operation indicator
lamp comes on and the heater motor &
circulating pump begin to run. After about 10-25
seconds the solenoid valve opens and fuel is
sprayed into the combustion chamber. At the
same time the electronic ignition unit produces
high voltage (8000V) and the mixture of fuel and
air in the combustion chamber is ignited by the
spark on the ignition electrodes. The flame is
indicated by the flame detector, then the
electronic ignition unit stops producing high
voltage and combustion continues by itself
(spark on electrodes is required only to ignite
the flame). At this moment the heater is working
and produces heat.
If the heater is switched off by the on/off switch,
the solenoid valve interrupts fuel supply,
combustion stops and indicator lamp turns off.
Combustion air fan still blows air, cleaning the
combustion chamber of any fumes and cooling
down the combustion chamber.
circulation pump pumps coolant, making a purge
cycle for approximately 2-3 minutes, thus
protecting the heater against overheating.
If the heater is not switched off by the on/off
switch, the control thermostat will switch off the
heater when coolant temperature reaches 165°
± 6°F (75° ± 3°C) and turns it on at 154° ± 9°F
(68° ± 5°C).
(combustion) is off, the indication lamp and
coolant pump are on. Combustion air fan blows
air for 2-3 minutes and then turns off.

Main Breakers

Nine (9) main breakers may be installed on your
vehicle; six (6) of which are standard and three
(3) supplied only on vehicles with central A/C
system. Breakers CB2 to CB7 are standard and
4 - 15
Coolant
During this time the heater