The timing can be set to the applicable crank angles. A controlled quantity of lubricating oil flows
above, into and below the piston ring pack.
If an FCM-20 or bus becomes defective, the other FCM-20 module or bus makes sure that
control of the cylinder oil system continues. A passive failure indication is shown in the
WECS-9520.
6.2.4
Cylinder-related control functions
The cylinder-related control functions are as follows:
•
Volumetric injection control (VIT)
•
Exhaust valve control (VEO/VEC)
•
Starting valve control
•
Cylinder lubrication.
Each cylinder has an FCM-20. A redundant system bus gives communication between each
FCM-20.
All FCM-20 receive the crank angle signal from a redundant SSI bus.
If an FCM-20 becomes defective, the related cylinder is cut out. The remaining FCM-20
continue to operate, but the engine output decreases.
6.2.4.1
Fuel injection control
6.2.4.1.1
Injection valve - control
Each injection valve related to the rail valve of a cylinder is controlled independently, but with
one common feedback signal for the injected fuel quantity.
Fuel injection starts at the same time for all injectors, but ends at different times. The injection
valves on each cylinder operate at the same time.
To improve the spray at low load, one or two injection valves are cut out automatically.
The FCM-20 increases the control outputs up to the applicable signal level for the rail valves.
6.2.4.1.2
Rail valve ON-time
The supply to the rail valve is cut off as soon as the valve piston has moved. This is the
measured ON-time and is shown in the remote control.
The measured ON-time gives data about the rail valve condition.
6.2.4.1.3
Initial set-pulse
Because the rail valves are bistable, their initial position is not specified. Thus, when the engine
is stopped, set-pulses are sent to the rail valves at intervals to get a specified position.
X92DF
AA00-0000-00AAB-043K-A
Operation Manual
Engine control system WECS-9520
Winterthur Gas & Diesel Ltd.
- 263 -
Issue 002 2020-08
