WÄRTSILÄ Vasa R22, Instruction Manual

Page: 274 / 297

22.7 Starting fuel limiter
22.7.1 General
Always when starting either automatically, remotely or manu-
ally, a limiter automatically limits the injected fuel quantity.
Always when the engine is not operating, the three-way solenoid
valve (4), Fig 22-4, is energized connected to the air distributing
pipe with the limiting cylinder. As the main starting valve is
opened when starting the engine, starting air is admitted to pass
from the distributing pipe through a non-return valve (8) to the
limiting cylinder, whereby the piston (1) is forced out, thus
limiting the fuel injection by a lever (7) which is fastened to the
control shaft. As the engine reaches a speed of 100 RPM below
the nominal speed, a relay in the speed measuring system de-en-
ergizes the solenoid valve (4). The de-energizing is delayed for two
seconds so that the engine reaches the nominal speed before the
limitation is cut off.
The pressure is relieved through the nozzle (5). On main engines
started up to a lower speed, a lower de-energizing speed may also be
used.
22.7.2 Check and adjustment of limitation
a) Check of limit position
•
set the stop lever in work position and the terminal shaft
lever in maximum fuel position,
•
connect pressure air to the nozzle (5), Fig 22-4, at which the
limiter piston (1) will turn the control shaft to the limit
position,
•
check the fuel rack position. The suitable limitation depends
on the installation, normally about 18 mm.
b) Adjustment of limit position
•
connect pressure air to the nozzle (5),
•
loosen the fastening screw (3) of the limitation lever,
•
turn the control shaft to the desired limitation of the fuel rack
position,
•
move the limitation lever against the limitation piston (1).
Tighten the fastening screw in this position,
•
check according to pos. a) above.
c) Check of function
See section 22.7.3.
22.7.3 Check of function
1 Check that limitation is achieved as soon as the main
starting valve opens.
22-9601 Control Mechanism 22
VASA 22 22 - 13