WÄRTSILÄ 12V46F Product Manual Download

Page: 151 / 200

●

External start blocking 1 (e.g. reduction gear oil pressure)

●

External start blocking 2 (e.g. clutch position)

●

Engine running

For restarting of a diesel generator in a blackout situation, start blocking due to low
pre-lubricating oil pressure can be suppressed for 30 min.

14.2.2

Stop and shutdown

Normal stop is initiated either locally with the stop button, or from a remote control station.
The control devices on the engine are held in stop position for a preset time until the engine
has come to a complete stop. Thereafter the system automatically returns to “ready for start”
state, provided that no start block functions are active, i.e. there is no need for manually
resetting a normal stop.

Manual emergency shutdown is activated with the local emergency stop button, or with a
remote emergency stop located in the engine control room for example.

The engine safety module handles safety shutdowns. Safety shutdowns can be initiated either
independently by the safety module, or executed by the safety module upon a shutdown
request from some other part of the automation system.

Typical shutdown functions are:

●

Lubricating oil pressure low

●

Overspeed

●

Oil mist in crankcase

●

Lubricating oil pressure low in reduction gear

Depending on the application it can be possible for the operator to override a shutdown. It is
never possible to override a shutdown due to overspeed or an emergency stop.

Before restart the reason for the shutdown must be thoroughly investigated and rectified.

14.2.3

Speed control

14.2.3.1

Main engines (mechanical propulsion)

The electronic speed control is integrated in the engine automation system.

The remote speed setting from the propulsion control is an analogue 4-20 mA signal. It is also
possible to select an operating mode in which the speed reference can be adjusted with
increase/decrease signals.

The electronic speed control handles load sharing between parallel engines, fuel limiters, and
various other control functions (e.g. ready to open/close clutch, speed filtering). Overload
protection and control of the load increase rate must however be included in the propulsion
control as described in the chapter "Operating ranges".

For single main engines a fuel rack actuator with a mechanical-hydraulic backup governor is
specified. Mechanical back-up can also be specified for twin screw vessels with one engine
per propeller shaft. Mechanical back-up is not an option in installations with two engines
connected to the same reduction gear.

14.2.3.2

Generating sets

The electronic speed control is integrated in the engine automation system.

The load sharing can be based on traditional speed droop, or handled independently by the
speed control units without speed droop. The later load sharing principle is commonly referred
to as isochronous load sharing. With isochronous load sharing there is no need for load

Wärtsilä 46F Product Guide - a19 - 1 December 2017

14-7

14. Automation System

Wärtsilä 46F Product Guide