Starting Box

08028-0D/H5250/94.08.12

Description

The starting box is mounted on the engine's control side. On front of the box there are the following indications/pushbuttons:

-Indication of engine or turbocharger RPM

-Indication of electronic overspeed

-Pushbutton for "Manual Start"

-Pushbutton for "Manual Stop"

-Pushbutton for "Remote" *

-Pushbutton for "Local" *

-Pushbutton for "Blocking" *

-Pushbutton for change-over between engine and turbocharger RPM

*The function chosen is indicated in the pushbutton. See fig 1.

Manual Start

The engine can be started by means of the start button, but only if the button "Local" is activated.

The manual, local start is an electrical, pneumatic start, i.e. when activating the start button a solenoid valve opens for air to the air starter, thereby engaging the starter and starting the diesel engine. Throughout the starting cycle the start button must be activated.

The air starter is automatically disengaged when the diesel engine exceeds 140 RPM. If the start button is disengaged before the diesel engine has exceeded 140 RPM, further starting cycles are blocked, until 5 sec. after the engine is at standstill.

Remote Start

Remote start can only take place if the pushbutton for "Remote" is activated.

Manual Stop

The "Manual Stop" button is connected to the stop coil on the governor.

Blocking

If "Blocking" is activated, it is not possible to start the diesel engine.

Engine / Turbocharger RPM

By activating the "Engine RPM/TC RPM" button, the indication is changed.

Engine RPM indication is green light-emitting diodes and turbocharger RPM indication is red light-emitting diodes.

External Indications

There are output signals for engine RPM and

The pushbuttons for "Remote", "Local" and "Blocking" have potential free switches for external indication.

All components in the starting box are wired to the built-on terminal box.

Fig 1. Starting box

08028-0D/H5250/94.08.12

Engine RPM signal

For measuring the engine's RPM, a pick-up mounted on the engine is used giving a frequency depending on the RPM. To be able to show the engine's RPM on an analogue tachometer, the frequency signal is sent through an f/I converter (frequency/current converter), where the signal is transformed into a proportional 4-20 mA ~ 0-1200 RPM signal.

Further, the converter has following signals:

-overspeed

-engine run

-safe start

-tacho fail

Fig 1. Converter for engine RPM.

Overspeed

When the engine speed reach the setpoint for electronic overspeed the converter gives a shutdown signal and a alarm signal through a relay.

Engine run

When the engine speed reach 710 RPM or 200 RPM + 10 seconds the converter gives a "engine run" signal.

The engine run signal will be deactivated when the speed is 640 RPM. If the engine speed haven't been over 710 RPM the signal will be deactivated at 200 RPM.

L23/30H

The "engine run" signals will be given through a relay. One for synchronizing and one for start/stop of pre. lub. oil pump or alarm blocking at start/stop.

Safe start

When the safe start signal is activated the engine can start. When the engine reach 140 RPM the air starter will be shut-off.

Further, the safe start signal is a blocking function for the air starter during rotation.

Tacho fail

The tacho fail signal will be on when everything is normal. If the pick-up or the converter fails the signal will be deactivated. E.g. if there is power supply failure.

The converter for engine RPM signal is mounted in the terminal box on the engine.

Turbocharger RPM signal

For measuring the turbocharger RPM, a pick-up mounted on the engine is used giving a frequency depending on the RPM. To be able to show the turbocharger's RPM on an analogue tachometer, the frequency signal is sent through a f/I converter (frequency/current converter), where the signal is transferred into a proportional 4-20 mA ~ 0-60000 RPM.

Fig 2. Converter for TC RPM.

The converter is mounted in the terminal box on engine.

08028-0D/H5250/94.08.12

L23/30H

Maintenance of monitoring and safety systems.

One of the most important parameters in the preventive work is that the alarm system as well as the shutdown and overspeed devices are functioning 100%.

If some of these functions are out of operation, they have to be repaired immediately. If this is not possible because of the present working situation, the engine has to be under constant observation until it can be stopped.

It is recommended that all functions are tested every three months according to the mentioned working cards.

The extent of the alarm and safety functions is variable from plant to plant.

For check of these functions use the working cards mentioned under related procedure on page 1.