Generator Set Control Panel for Switchgear Conversion Caterpillar

Engine Shutdown

Usage:

The most common method of shutting down the engine is by opening the remote start switch. The remote start switch is located in the switchgear. On 3412 PEEC and 3412/3500 MUI engines, the engines may be shutdown by the control board.

3412 PEEC And 3412/3500 MUI Engine Shutdown

If any of the following conditions exist, the control board will automatically shut down the engine. The corresponding fault indicator will illuminate.

The engine has not started after three periods of crank and rest. These periods last for ten seconds and these periods are determined by the control board.
The engine water temperature has risen above the upper limit of the water temperature switch (WTS).
The engine oil pressure has fallen below the low limit of the engine oil pressure switch (OPS).
The control board has determined an engine overspeed.
The emergency stop push button (ESPB) has been pressed.
The spare fault indicator has been programmed for shutdown and the spare fault is present.

If the spare fault indicator is programmed for an alarm, the control board illuminates the spare fault indicator. The engine is NOT shutdown.

The remote start switch must be opened in order to reset the control panel. The remote start switch must also be opened in order to turn the fault indicator OFF. When the fault is no longer present, the remote start switch must be opened. The remote start switch is located in the switchgear.

The following topics describe the shutdown methods.

An Engine Shutdown That Is Caused By Overcrank

After a period of engine cranking, the control board determines if the engine has been started. This determination is made when the total cycle crank time has elapsed. If the engine has not started, the control board performs an automatic engine shutdown. The control board will also perform the following functions:

stop fuel flow.
open the shunt trip circuit breaker.
illuminate the overcrank fault indicator.
activate the optional general alarm relay.

The engine should not be allowed to start until the fault is corrected.

Note: See Systems Operation, "Cycle Cranking" for more information.

The control board will remove the "B+" voltage from the fuel-on output (connector contact 9) of the control board in order to stop the flow of fuel. The coils of FCR1 and FCR2 will deactivate and the normally open contacts will open. This de-energizes the fuel control solenoid which stops the flow of fuel to the engine and the engine shuts down.

The control board supplies "B+" voltage to the shunt trip output (connector contact 17 of the control board) in order to open the shunt trip circuit breaker. The coil of the shunt trip relay will energize and the circuit breaker main contacts will open. The generator line voltage is now disconnected from service.

To sound the optional alarm, the control board supplies "B+" voltage to the general alarm output. The general alarm output is located at connector contact 2 of the control board. The coil of the alarm relay will energize and the normally open contacts will close. The optional alarm is powered by "B+".

Procedure To Restart The Engine

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Accidental engine starting can cause injury or death to personnel working on the equipment.
To avoid accidental engine starting, disconnect the battery cable from the negative (-) battery terminal. Completely tape all metal surfaces of the disconnected battery cable end in order to prevent contact with other metal surfaces which could activate the engine electrical system.

Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

Open the remote start switch. The overcrank fault indicator turns off. "B+" voltage is removed from the start signal input. The start signal input is located at connector contact 24 of the control board. B+ voltage is removed from the system reset input. The system reset input is located at connector contact 22 of the control board.

Correct the cause of the overcrank fault. See Testing And Adjusting, "Shutdown Indicator Troubleshooting" for more information.

Close the circuit breaker.

The system is ready to start when the remote start switch is closed.

Engine Shutdown That Is Caused By Activating The Emergency Stop Push Button (ESPB)

The control board performs an automatic engine shutdown when the engine has determined that the ESPB has been pressed. The control board has an emergency stop input at connector contact 20. The emergency stop input connects to the normally open contacts of the ESPB. When the ESPB is pressed, the emergency stop input connects to "B-" through the contacts of the ESPB. The contacts of the ESPB are now closed. Also when the ESPB is pressed, the ESPB stops the flow of fuel to the engine. This prevents the engine from cranking. When the control board receives the emergency stop signal, the following functions are performed:

The control board activates the optional air shutoff solenoid (ASOS).
The control board turns off the fuel-on signal.
The shunt trip circuit breaker is opened.
The indicator for the emergency stop fault is illuminated.
The optional general alarm relay is activated.

Note: The process will occur if the ESPB on the control panel or the optional ESPB on the enclosure is pressed. The ESPB should NOT be used for normal stopping of the engine.

The ESPB opens the "B+" signal from the fuel-on output of the control board. The signal goes to the coils of FCR1 and FCR2 in order to stop the flow of fuel to the engine. Connector contact number 9 is the connector pin designation for the fuel-on output. The coils of FCR1 and FCR2 will deactivate and the normally open relay contacts will open. This de-energizes the fuel control solenoid which stops the flow of fuel to the engine and the engine shuts down.

The ESPB opens the starting motor signal from the starting motor output of the control board to the coil of SMMS1 in order to prevent engine cranking. The starting motor output is found on the control board (connector contact number 13). The normally open relay contacts of SMMS1 will remain open regardless of any attempts by the control board to activate the SMMS1. The starting motor is disabled and the engine will not crank.

The control board supplies system voltage to the shunt trip output (connector contact 17 of the control board) in order to open the shunt trip circuit breaker. The coil of the shunt trip relay will energize and the circuit breaker main contacts will open. The generator line voltage is now disconnected from service.

To sound the optional alarm, the control board supplies "B+" voltage to the general alarm output (connector contact 2 of the control board). The coil of the alarm relay will energize and the normally open contacts will close. The optional alarm is powered by the "B+".

When the air shutoff solenoid is energized by the control board, the optional air shutoff damper is activated. The air shutoff damper prevents air from entering the engine. A battery negative signal energizes the air shutoff solenoid. A spade-type connector that is located on the control board provides this signal ("B-").

Procedure To Restart The Engine

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Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

Open the remote start switch. The overcrank fault indicator turns off. Battery positive voltage is removed from the following connector contacts:
- the start signal input (connector contact 24 of the control board)
- the system reset input (connector contact 22 of the control board)

Reset the ESPB by turning clockwise. The emergency stop fault indicator turns off.

Correct the fault that required the emergency stop.

Reset the optional air shutoff damper.

Close the circuit breaker.

The system is ready to start when the remote start switch is closed.

An Engine Shutdown That Is Caused By An Engine Overspeed Fault

When the control board has determined that the engine speed has increased above the internal overspeed setting (118% of rated speed), the control board performs an automatic engine shutdown. The control board monitors engine speed from the magnetic pickup inputs (connector contacts 8 and 10). The control board is responsible for the following functions:

activation of the optional air shutoff solenoid (ASOS)
stopping the flow of fuel
opening of the shunt trip circuit breaker
illumination of the overspeed fault indicator
activation of the optional general alarm relay

Note: For more information, refer to Systems Operation, "Overspeed Protection".

To stop the flow of fuel, the control board removes "B+" voltage from the fuel-on output (connector contact 9) of the control board. The coils of "FCR1" and "FCR2" will deactivate and the normally open contacts will open. This de-energizes the fuel control solenoid which stops the flow of fuel to the engine and the engine shuts down.

To open the shunt trip circuit breaker, the control board supplies "B+" voltage to the shunt trip output (connector contact 17 of the control board). The coil of the shunt trip relay will energize and the circuit breaker main contacts will open. The generator line voltage is now disconnected from service.

Procedure To Restart The Engine

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Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

Open the remote start switch. The overspeed fault indicator turns off. Battery positive voltage is removed from the following connector contacts:
- the start signal input (connector contact 24 of the control board)
- the system reset input (connector contact 22 of the control board)

Correct the cause of the engine overspeed fault. Refer to Testing And Adjusting, "Shutdown Indicator Troubleshooting".

Reset the optional air shutoff damper.

Close the circuit breaker.

The system is ready to start when the remote start switch is closed.

An Engine Shutdown That Is Caused By A High Coolant Temperature Fault

The control board performs an automatic engine shutdown when the engine coolant temperature rises above the upper limit of the water temperature switch (WTS). At this time, the WTS closes. The WTS provides a battery negative signal to the coolant temperature input (connector contact 15 of the control board). The control board also performs the following functions:

stop fuel flow.
open the shunt trip circuit breaker.
illuminate the high coolant temperature fault indicator.
activate the optional general alarm relay.

Note: After the engine reaches crank termination speed, there is a 15 second delay before the coolant temperature input (connector contact 15) becomes activated. The time delay is controlled by the fault protection timer (FPT), located on the control board. The 15 second time delay allows the engine to be restarted without load after a high coolant temperature fault. The engine is started without load in order to circulate water which will cool the engine.

To stop the flow of fuel, the control board removes "B+" voltage from the fuel-on output (connector contact 9) of the control board. The coils of FCR1 and FCR2 will deactivate and the normally open contacts will open. This de-energizes the fuel control solenoid which stops the flow of fuel to the engine and the engine shuts down.

Procedure To Restart The Engine

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Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

Open the remote start switch. The high coolant temperature fault indicator turns off. "B+" voltage is removed from the start signal input (connector contact 24 of the control board) and from the system reset input (connector contact 22 of the control board).

Correct the cause of the high coolant temperature fault. Refer to Testing And Adjusting section, "Shutdown Indicator Troubleshooting".

Close the circuit breaker.

The system is ready to start when the remote start switch is closed.

An Engine Shutdown That Is Caused By A Low Oil Pressure Fault

The control board performs an automatic engine shutdown when the engine oil pressure has fallen below the low limit of the engine oil pressure switch (OPS). At this time, the OPS closes. When the OPS closes, a "B-" signal is provided to the oil pressure input (connector contact 7 of the control board). The control board also performs the following functions:

stop fuel flow.
open the shunt trip circuit breaker.
illuminate the low oil pressure fault indicator.
activate the optional general alarm relay.

Note: After the engine reaches crank termination speed, there is a 15 second delay before the oil pressure input (connector contact 7) becomes activated. The time delay is controlled by the fault protection timer, located on the control board. The 15 second time delay allows the initial oil pressure to increase. The increase in the initial oil pressure opens the oil pressure switch.

Procedure To Restart The Engine

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Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

Open the remote start switch. The low oil pressure fault indicator turns off. "B+" voltage is removed from the start signal input (connector contact 24 of the control board) and from the system reset input (connector contact 22 of the control board).

Correct the cause of the low oil pressure fault. Refer to Testing And Adjusting, "Shutdown Indicator Troubleshooting".

Close the circuit breaker.

The system is ready to start when the remote start switch is closed.

An Engine Shutdown That Is Caused By A Spare Fault

The control board provides one spare fault input (connector contact 12). Various optional factory devices can be connected to the spare fault input. A customer provided device can also be connected to the spare fault input. The response of the control board to a spare fault is selectable. This response can be either an alarm fault or a shutdown fault. A spare fault can be used as a shutdown fault. In this case, the fault protection timer (FPT) is selectable. When there is a battery negative signal at the spare fault input, the control board will respond in a preselected manner: alarm versus shutdown and FPT versus no FPT. For more information, see Systems Operation, "Fault Management".

Some of the optional factory devices that can be connected to the spare fault input are listed below.

Engine Coolant Loss Sensor
Over/Under Voltage Relay
Ground Fault Relay
Low Fuel Level Switch
High Fuel Level Switch

Note: If the spare fault is selected as an alarm fault, the control board has only one response. The control board must illuminate the spare fault indicator and the control board must energize the general alarm output. After the alarm fault is corrected, the spare fault indicator is reset by activating the lamp test switch.

If the spare fault is selected as a shutdown fault, the control board performs the following operations.

When the spare fault device provides a "B-" signal to the spare fault input of the control board, the control board performs an automatic engine shutdown. The spare fault input of the control board is connector contact number 12. The control board performs the following functions:

closure of the fuel flow tube
opening of the shunt trip circuit breaker
illumination of the spare fault indicator
activation of the optional general alarm relay

Procedure To Restart The Engine

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Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

Open the remote start switch. The spare fault indicator turns off. "B+" voltage is removed from the start signal input (connector contact 24 of the control board) and from the system reset input (connector contact 22 of the control board).