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Manual
F 240
5. General
6. Speed
measuring
system
Ver. 01
ALARM AND SAFETY SYSTEM
10A
10A
DESCRIPTIONS
DESCRIPTIONS
The engine is provided with equipment for protection against several kinds of faults.
The engine protection system is divided into:
-- speed transmitter ;
-- alarm and protection switches ;
-- alarm and protection unit
-- co--signaling board
For a general description see points 2 to 5 of this section.
The alarm and protection system can be delivered, suitable for flush mounting, for wall
mounting or in a switch board.
Depending on the performance and application of the engine, either (stationary)
generator duty or propulsion, the speed governor is provided with and controlled by
an electric speed adjusting motor or a pneumatic speed adjusting cylinder for remote
control. At any load, the engine speed which was adjusted by the speed governor, can
be changed remotely with this motor or cylinder.
The electric speed adjusting motor is also of importance when a number of engines
are working in parallel on one electrical system. In this case, it is necessary to
synchronize the speed of the engine to be switched in, before switching on the circuit
breaker.
With the electric speed adjusting motor it is also possible to correct the load distribution
over the engines. If necessary, this can be done while they are working in parallel.
For information about the engine speed governor see the SUB--SUPPLIERS
MANUALS.
To achieve the necessary signals and speed dependent switch functions, the engine
is provided with an electronic speed transmitter with an electro--magnetic speed
sensor.
See section 10C for the diagram, in the standard design, comprising the following
components:
6. 1. Electro- -magnetic speed sensor (B):
An electro--magnetic speed sensor directed of the teeth of the camshaft--
gearwheel, provides the signal for the speed transmitter.
This sensor provides a frequency signal to the speed transmitter, equal to the
number of teeth of the camshaft gearwheel passing every second.
6. 2. Supply card (E1):
The speed transmitter is provided with a supply card, which takes care of the
necessary stabilised voltages for the other components of the system.
The required input voltage for this card itself is standard 24 volt DC (min. 20 and
max. 32 volt, including eventual ripples)
6. 3. Key- -switch (2):
In order to be able to test the proper functioning of the overspeed protection the
speed transmitter is provided with a key switch with two positions:
-- "normal", the standard overspeed protection functions as adjusted will trip
the engine at an actual speed of 1.15 times the rated speed ;
-- "test", In the case of an engine in operation the increase of engine speed is
simulated and the overspeed relay will be actuated at approx. 60% of the rated
speed.
optional delivery ;
optional delivery.
10 - - 1
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