WÄRTSILÄ Vasa R22, Instruction Manual

Page: 289 / 297

23.2.4 Engine Speed Sensor
a) Theory of operation: The sensor is an inductive, touchfree
poximity switch supplied with +12 V and 0 V DC. The third pin
is a speed-proportional pulse train.
The electronics of the sensor is resin-moulded into a tubular
housing of nickel plated brass with external thread of
18
x 1.5 mm. The three-wire cable is connected by means of a
four-pole connector (Euchner BS4 ).
b) Mounting the sensor: Turn the engine until the top of a cog is
visual in the sensor mounting hole. Screw the sensor com-
pletely in. Unscrew the sensor 2,5 mm and tighten it well to
the shown sensing displacement (see Fig 23 - 7)
The output signal (terminal 55 in the electronic box or TP1 on
the nDE-card) should now be appr. 12 V DC. If the sensor is
between two cogs, the output will show appr. 0 V.
Note! The engine must not run while the sensor is mounted.
Engine speed sensor
A
2.5mm = 1 3/4 turns
on the sensor
+12VDC
GND
1
2
3 4
A-A
SIGNAL
A
Fig 23 - 7
2223598935
23 Instrumentation and Automation 22-9601
23 - 14 VASA 22