3408 AND 3412 INDUSTRIAL AND EPG DIESEL ENGINES Caterpillar

Automatic Start-Stop

An automatic start-stop system is used when an engine must start when a specific condition occurs with no one in attendance. The engine will start, increase speed, pick-up the load, operate the load until a second condition occurs, remove the load, cool and stop. The following conditions must exist for the engine to start unattended:

Either the ambient (engine room) temperature must be at least 70°F (20°C); or, the engine jacket water temperature must be at least 90°F (32°C). One or two 3 kw jacket water heaters can maintain this temperature.

Protection Devices

The Caterpillar generator mounted control panel is equipped with protection devices to protect the engine while cranking.

Batteries

Lights or buttons may indicate if a fault has occurred in the battery charging system causing the battery to be either undercharged or overcharged.

Overcranking

A timer allows the engine to crank either once for 30 seconds, or to crank through 5 ten-second cranking cycles (depending upon the device used) while unattended. If the engine does not start before the time elapsed, the fuel system will be shutoff and a light will indicate a starting failure.

Engine Operation

Prealarm systems provide an audible and/or a visual indication for low oil pressure, high water temperature, low fuel supply or low jacket water temperature before the condition becomes critical. These alarms are self resetting when the condition is corrected.

The engine may also be equipped with shutdown devices. If low oil pressure, high jacket water temperature or an engine overspeed condition occurs, the engine will be shutdown and a corresponding button or light will indicate the cause of the shutdown. These devices must be reset after repairs have been made and before starting. See the topic, EMERGENCY SHUTOFF DEVICES AND ALARMS.

Generator set control panels should be equipped with an ammeter, a frequency meter and a voltmeter. Depending upon the type of operation, the panel may also be equipped with other meters and lights. Know these instruments and their normal readings. They will indicate how the generator set is performing.

Shutting Down

A timer allows the transfer switch to transfer the load to another source and to continue engine running for up to 2 minutes for cooling purposes before stopping.

Engine Exerciser

At preset times, the exerciser will start, run and stop the engine in order to ensure both proper lubrication of all engine parts and proper equipment operation if and when the standby unit is needed.

Become familiar with all instructions included with the equipment.

Woodward Governors

Woodward Governors are usually electrically operated from a control panel.

Generator Set Control Panel

The generator set control panel is located on top of the generator and is equipped with the following controls and gauges:

Panel lights (1) are controlled by an ON/OFF switch (7). An ammeter (2), frequency meter (3) and a voltmeter (4) show the output of the generator. Two gauges (5 and 6) show engine oil pressure and water temperature respectively. The ammeter selector switch (12) gives the operator a choice of which phase (T1, T2 or T3) of the generator output the ammeter (2) will show. Voltage level rheostat (9) takes the place of the voltage level rheostat in the generator regulator assembly.

The engine control switch (8) has four positions; MANUAL, AUTOMATIC, STOP and OFF. Placing the control in the MANUAL position will start the engine and allow the operator to manually connect the generator to the load. If the unit is used for standby application with a remote transfer switch, the AUTOMATIC position is used. In this position the engine will automatically start and take up the load when commercial power has stopped. Placing the control in the STOP or OFF position will stop the engine. When in the AUTOMATIC or MANUAL position, the engine will automatically stop if the commercial power has started or if the engne has a fault.

The PSG governor control switch allows the operator to control the engine rpm from the panel. If the engine is equipped with glow plugs, they are controlled by an ON/OFF heat switch (15).

If the engine has a fault, engine failure light/reset switch (11) will operate. The light/switch (11) will activate a shutdown relay to stop the engine. A shutdown indicator (14) will also operate to show the cause of the fault. The shutdown indicators (14) give an indication that the fault was either oil pressure, water temperature or overspeed. A fourth shutdown indicator will show an overcrank condition. A D.C. ammeter and a governor control switch will take the place of buttons (10 and 13) respectively if ordered. The shutdown indicators have four auxiliary contacts; one for each time its shutdown indicator operates. The contacts are connected to a remote annunciator panel if ordered.

The shutdown indicator lights can be checked for malfunction by depressing the shutdown indicators. Replace burned out bulbs immediately.

CONTROL PANEL
1. Panel lights. 2. Alternating current ammeter. 3. Frequency meter. 4. Alternating current voltmeter. 5. Oil pressure gauge. 6. Water temperature gauge. 7. ON/OFF toggle switch for panel lights. 8. Engine control switch. 9. Voltage level rheostat. 10. Button (direct current ammeter if ordered). 11. Engine failure light/reset switch. 12. Ammeter selector switch. 13. Button (governor control switch if engine is equipped with a PSG governor). 14. Shutdown indicator (oil pressure, water temperature, overspeed and overcrank). 15. Button; heat switch (if so equipped). 16. Panel; prealarm module (if so equipped).

Starting The Engine

1. Perform all prestart checks outlined previously.

2. Place the CONTROL switch in the MANUAL position to crank the engine.

3. When the engine starts and engine rpm reaches 600 rpm and the oil pressure registers 22 psi (1.5 kg/cm²) the starting motor will automatically disconnect from the start circuit.

4. Start the load.

5. Regulate the engine speed with the RAISE-LOWER switch to the required instrument panel gauge readings.

Stopping The Engine

1. Remove the load. See GENERATOR SET OPERATION instructions if equipped with an electric set generator.

2. Reduce engine speed to low idle: Push down and hold the RAISE-LOWER switch until the engine low idle speed is reached.

3. While the engine is idling, check the engine oil level. Oil level must be maintained between the ADD and FULL marks on the side of the dipstick marked "CHECK WITH ENGINE RUNNING".

4. Stop the engine.

Solenoid Shutoff

a. Move the control switch to the STOP or OFF positions. (Do not confuse this with the "RAISE-LOWER" switch.)

ON-OFF-STOP SWITCH

PSG Governor:

b. Move the shutoff lever forward, or hold the lever up, depending upon installation. Hold the lever in this position until the engine stops.

5. Fill the fuel tank. See the LUBRICATION AND MAINTENANCE section.

6. Drain the raw water system if below freezing temperatures are expected.

7. Observe the Service Meter reading. Perform the periodic maintenance as instructed in the LUBRICATION AND MAINTENANCE CHART.

Emergency Shutoff Devices And Alarms

Emergency shutoff devices are either electrically, mechanically or hydraulically operated. Familiarize yourself with the types and locations of the shutoff devices, the conditions which cause each control to function, and the resetting procedure required to start your engine.

The operation of all electric shutoff controls is similar: A critical operating condition actuates a switch which closes the circuit to the shutoff solenoid, which stops the engine. The shutoff control may require resetting before the engine can start.

High Water Temperature Shutoff

The shutoff switch is located in the water temperature regulator housing. Excessive water temperature closes the switch. No resetting procedure is required: As the coolant cools, the switch opens.

Low Oil Pressure Shutoff Switch

This device is usually mounted on the side of the engine, and oil lines are connected to the switch. Low oil pressure closes the switch.

Manually operated systems require resetting of this switch before starting. Automatic start-stop systems use a pressure switch which resets itself.

To reset the switch, push the button until it latches. After the engine starts and develops oil pressure, the button will move to the extended running position.

Overspeed Shutoff Switch (Electronic)

This switch senses engine speed. The control box is mounted on the engine block. Excessive engine speed closes a circuit breaker. To reset the switch, push the reset button.

Fuel/Oil Pressure Switch

This switch is mounted in the fuel manifold between the outlet side of the fuel filter and the fuel injection pump. Low fuel pressure opens the switch and the electrical circuit to either the shutoff solenoid or the circuit between the alternator and the alternator regulator. While the engine is stopped, open these circuits to prevent the battery from becoming discharged.

This switch can also be used with an electric governor. In this application, oil pressure closes the switch to allow the electric governor to control engine speed.

This switch does not require resetting.

Air Safety Shutoff Control

The air shutoff control is an attachment to the safety shutoff devices. When an emergency conditions occurs, the solenoid pushes the rack into the shutoff position and a solenoid trips a butterfly valve, located in the inlet manifold, to the closed position. The air safety shutoff control must be reset before starting.

Alarm Switches

Alarm switches are set at a less critical temperature, pressure, or level limit than the comparable shutoff control. The purpose of the alarm switch is to warm the operator an unsafe operating condition is starting to occur, and that corrective measures should be taken to avoid possible damage to the engine and/or a possible shutdown of the engine.

When the preset temperature, pressure or fluid level occurs, either a light or an audible alarm will be energized. The light or alarm will continue to operate until the condition is corrected. When the condition is corrected the alarm will automatically reset and the light will turn off.

Testing Indicator Lights

Most control panels are equipped with a test switch. By turning the switch ON, all of the indicator lights can be checked for proper operation. Test the indicator lights periodically, replace burned out light bulbs immediately.

Alarm Shutoff Switch

A switch may be installed in the alarm circuit for silencing the alarm while the engine is stopped for repairs. Be sure the switch is moved to the closed (ON) position and the warning lights are lit before starting.

Output Shaft Governor Operation

When the load can overspeed the torque converter output shaft, an output shaft governor should be installed. The output shaft governor is a speed limiting device which automatically adjusts engine governor setting according to load requirement.

Determining Cause Of Shutdown

Low Oil Pressure Checks

If the low oil pressure shutoff control has stopped the engine, make the following checks:

1. Check the water temperature gauge. Determine if the engine was overheated. Check for external water leaks.

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Beware of steam or scalding water. Do not attempt to loosen the radiator cap until the temperature gauge indicates the coolant has sufficiently cooled. Then, loosen the cap slowly.

2. Check the oil level. Oil level must be between the ADD and FULL marks on the side of the dipstick stamped CHECK WITH ENGINE STOPPED.

3. If the oil level is below the ADD mark, check for oil spray and/or oil accumulations. If any are found, have the necessary repairs made. Before starting, add oil to the FULL mark.

4. Reset the shutoff control.

5. Remove the load and start the engine at its slowest speed. Be prepared to shut the engine down manually.

6. Be alert for unusual sounds or noises. If the engine knocks, stop the engine immediately and call your Caterpillar dealer.

7. If the engine blows excessive black exhaust or has excessive crankcase blow-by, the engine may need reconditioning. Stop the engine and call your Caterpillar dealer.

8. If the engine runs satisfactorily, observe the oil pressure gauge. If satisfactory pressure is not indicated, shut the engine down; call your Caterpillar dealer.

9. If proper oil pressure is registered, check to see if the reset knob has moved to the run position. If the knob does not move, stop the engine. Check the shutoff control, the oil line, and the oil pressure gauge. Have necessary repairs made.

10. If the oil pressure gauge registers normal oil pressure, if the knob on the shutoff control moves to the run position, and if the engine operation is otherwise satisfactory, determine if the high water temperature shutoff may have shut down the engine.

High Water Temperature Checks-Engine Running

1. Determine if the load was too great for the engine: Reduce the load and allow the engine to cool while running.

2. If pressure steam or water leaks are visible, remove the load and stop the engine. Have necessary repairs made.

3. Check for collapsing or deteriorated water hoses. Have repairs made.

4. Check for noisy water pump operation. Have necessary repairs made.

5. Refill the cooling system with a solution of water and permanent-type antifreeze if below freezing temperatures are expected; or with a solution of approved water and Caterpillar Corrosion Inhibitor or equivalent. Follow the instructions on the container.

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DO NOT remove the pressure cap on an overheated engine. The coolant is under pressure and relieving the pressure will cause the coolant to flash into steam. Serious flash burns and engine damage can result. If necessary, reduce pressure in a surge tank by pouring warm water on top of the tank. Never add cold water to a hot engine.

NOTE: If there is adequate coolant in the cooling system, gradual cooling is preferred by running the engine a half speed. This eliminates hot spots in the engine, and possible failure.

High Water Temperature Checks-Engine Stopped and Cold

1. Check coolant level. Determine if the coolant has proper antifreeze protection. A 50-50 solution of permanent-type antifreeze and approved water will give protection below -20°F (-29°C).

2. Check to be sure the raw water valve has been opened.

3. Check engine room vents and/or louvers. Be sure the engine is receiving sufficient air.

4. Be sure temperature regulators are operating at proper temperature range.

5. Inspect all water hoses carefully for collapsing, external and internal failures. Replace hoses as required.

6. Have the cooling system cleaned.

Emergency Stopping

To stop in an emergency:

Mechanical Governor Control

Pull upward on the hand grip, and move the control to the shutoff position.

Woodward PSG Governor

Move the lever forward against the stop; hold the lever until the engine is stopped.

Electric Shutoff Solenoid

Push and hold the ON-OFF-STOP switch in the STOP position until the engine stops.

Air Controls

Push and hold the ON-OFF-STOP switch in the STOP position until the engine stops.