DAF CF65, CF75, CF85 Series . Manual — part 498
5
CF65/75/85 series ≥0E621376
Description of components
COMPONENTS
2-7
Inspection
The engine oil level sensor can be checked with
a multimeter set to the resistance range.
The resistance value is between 20.5 and 23.5
Ohms, measured at 20_C.
The maximum current strength of 200mA may
not be exceeded when the resistance value is
measured.
2.5 PRESSURE SENSORS
The vehicle has a number of pressure sensors,
such as:
-
Pressure sensor to record bellows pressure
for ECAS.
-
Pressure sensor on the air supply unit.
There is a diaphragm made of semi-conducting
material (silicon) in the pressure sensor.
When pressure is applied to the diaphragm, it
will be deflected.
Deflection of the diaphragm leads to a change in
the resistance of the semi-conducting material.
The diaphragm is part of a what is known as a
bridge circuit.
Deflection of the diaphragm unbalances the
bridge circuit, which changes the output signal.
The output voltage is in direct proportion to the
pressure applied (deflection of the diaphragm).
Inspection
The output voltage can be checked using a
multimeter set to the DC voltage range.
V
W 5 01 012
2
200404
5
COMPONENTS
Description of components
CF65/75/85 series ≥0E621376
2-8
Pressure sensor for monitoring boost
pressure.
A piëzo pressure sensor is used to check the
boost pressure. This sensor consists of an
electronic circuit and a pressure recording
element.
The pressure recording element records
changes in pressure; these changes in pressure
are converted into an electrical voltage. The
electronic circuit amplifies this voltage to create
a usable output signal.
Inspection
The output voltage can be checked using a
multimeter set to the DC voltage range.
i 400441
2.6 ALTERNATOR
The compact alternator is a lightweight
alternator with two internal cooling fans. The
electronic controller also controls pre-excitation
of the alternator. The function of the exciter
diodes has also been taken over by the
controller. The alternator generates high
currents in the lower speed range.
B
connection to terminal 30 on the starter
motor
15 voltage after ignition
S
sens connection on the controller
L
connection to VIC
B connection
The alternator has two B+ connections that are
connected to each other internally. B+1 is
connected to terminal 30 on the starter motor.
B+2 is NOT connected. B- (earth) is connected
to the alternator housing.
E501373
2
200404
5
CF65/75/85 series ≥0E621376
Description of components
COMPONENTS
2-9
Connection 15
When the ignition has been turned on (contact
made), power is supplied to the alternator via
connection 15 (1010). The controller uses this
power to activate pre-excitation
(self-energising). If there is an open circuit in this
connection, the alternator will not produce any
power until it reaches a speed of about 5000
rpm. This corresponds to an engine speed of
around 1500 rpm. The alternator will energise
itself when it reaches this speed.
Sens connection
The sens connection can be used to
compensate for voltage losses in B+. There are
voltage differences between the alternator and
the battery. Voltage regulation can be improved
if these voltage variations can be controlled. The
sens connection is connected to terminal 30 on
the starter motor.
L connection
The L connection is connected to the VIC
electronic unit.
This connection is used to activate a fault
message in the master display via the VIC, if
necessary.
L voltage high: no fault
L voltage low: fault
The following faults can be detected via the “L”
connection:
-
Voltage too low (< 16V)
-
Open circuit in connection 15 (1010)
-
Open circuit in “S” connection
-
Open circuit in “L” connection
These faults are indicated by the yellow
“Alternator fault” warning.
Too high a voltage (red warning) can be
recognised by too high a voltage (>31 V) on the
VIC electronic unit.
E501129
L
15
S
2
200404
5
COMPONENTS
Description of components
CF65/75/85 series ≥0E621376
2-10
2.7 PROXIMITY SENSORS
The vehicle has a number of proximity sensors,
such as:
-
sensor under the clutch pedal for engine
management
-
cab lock sensor
-
mechanical rear axle lifting-gear
Inductive proximity sensor
An alternating electromagnetic field is generated
by a pulsating current in a coil (oscillation).
If a metal object is introduced into the
electromagnetic field, eddy currents will occur in
that metal object.
These eddy currents will “damp” the magnetic
field in the coil, so that the current in the coil
changes.
This change results in an output voltage.
Inspection
Placing a metal object in front of the sensor
(inductive sensor) makes it possible to check the
output voltage using a multimeter set to the
direct voltage range.
W 5 01 014
E500551
2
200404
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст