D379, D398, D399 INDUSTRIAL & MARINE ENGINES Caterpillar


Systems Operations D379, D398, D399 I & M Engine Attachments

Usage:



Woodward UG8 Governors


SCHEMATIC OF UG8 LEVER GOVERNOR

Woodward UG8 Dial And Lever Governor

The UG8 Dial Governor is a mechanical-hydraulic governor. A hydraulic activated power piston is used to turn the output terminal shaft of the governor. A lever on the terminal shaft is connected to the fuel rack by a linkage rod. The governor has a separate oil supply and oil pump. The governor oil pump and ballhead are driven from a shaft in the governor drive housing. The shaft is driven by the fuel pump drive shaft.

The oil pump gives pressure oil to operate the power piston. The drive gear of the oil pump has a bushing in which the pilot valve plunger moves up and down. The driven gear of the oil pump is also the drive for the ballhead.

An accumulator is used to keep a constant oil pressure of approximately 120 psi (830 kPa) to the top of the power piston and to the pilot valve.

The power piston is connected by a lever to the output terminal shaft. There is oil pressure on both the top and bottom of the power piston. The bottom of the piston has a larger area than the top.

Less oil pressure is required on the bottom than on the top to keep the piston stationary. When the oil pressure is the same on the top and bottom of the piston, the piston will move up and cause the output terminal shaft to turn in the increase fuel direction. When oil pressure on the bottom of the piston is directed to the sump, the piston will move down and cause the output terminal shaft to turn in the decrease fuel direction. Oil to or from the bottom of the power piston is controlled by the pilot valve.

The pilot valve has a pilot valve plunger and a bushing. The bushing is turned by the governor drive shaft. The rotation of the bushing helps reduce friction between the bushing and the plunger. The pilot valve plunger has a land that controls oil flow through the ports in the bushing. When the pilot valve plunger is moved down, high pressure oil goes to the bottom of the power piston and the power piston will move up. When the pilot valve plunger is moved up, the oil on the bottom of the power piston is released to the sump and the power piston moves down. When the pilot valve plunger is in the center (balance) position, the oil port to the bottom of the power piston is closed and the power piston will not move. The pilot valve plunger is moved by the ballhead assembly.


SCHEMATIC OF UG8 DIAL GOVERNOR

The ballhead assembly has a ballhead, flyweights, speeder spring, thrust bearing, speeder plug, and speeder rod. The ballhead assembly is driven by a gear and shaft from the driven gear of the oil pump. The speeder rod is fastened to the thrust bearing which is on the toes of the flyweights. The speeder rod is connected to the pilot valve plunger with a lever. The speeder spring is held in position on the thrust bearing by the speeder plug.

As the ballhead turns, the flyweights move out due to centrifugal force. This will make the flyweight toes move up and cause compression of the speeder spring. When the force of the speeder spring and the force of the flyweights are equal the engine speed is constant. The speeder plug can be moved up or down manually to change the compression of the speeder spring and will change the speed of the engine.

The compensation system gives stability to engine speed changes. The compensation system has a needle valve and two pistons - an actuating piston and a receiving piston. The actuating piston is connected to the output terminal shaft by the compensation adjusting lever. A fulcrum that is adjustable is on the lever. When the position of the fulcrum is changed, the amount of movement possible of the actuating piston is changed.

The receiving piston is connected to the pilot valve plunger and the speeder rod by a lever.

The needle valve makes a restriction to oil flow between the oil sump and the two pistons.

When the actuating piston moves down, the piston forces the oil under the receiving piston and moves it up. When the receiving piston moves up it raises the pilot valve plunger to stop the flow of oil to the bottom of the power piston.

When the engine is in operation at a steady speed the land on the pilot control valve is in the center of the control port of the bushing. A decrease in load will cause an increase in engine speed. With an increase in engine speed the flyweights move out and raise the speeder rod and floating lever. This raises the pilot valve plunger and releases oil from the bottom of the power piston. As the power piston moves down the output terminal shaft moves in the decrease fuel direction. When the output terminal shaft moves, the actuating compensation piston moves up and causes a suction on the receiving piston which moves down. The floating lever is pulled down by the receiving piston and the lever moves the pilot control valve down to close the control port. The output terminal shaft and power piston movement is stopped. As the engine speed returns to normal the flyweights move in and the speeder rod moves down. When the oil pressure in the compensation system and the sump oil become the same through the needle valve, the receiving compensation piston moves up at the same rate as the speeder rod moves down. This action keeps the pilot valve plunger in position to close the port.

An increase in load will cause a decrease in engine speed. When engine speed decreases, the flyweights move in and lower the speeder rod and floating lever. This lowers the pilot valve plunger and lets pressure oil go under the power piston. The power piston moves up and turns the output terminal shaft in the increase fuel direction. When the output terminal shaft moves, the actuating compensation piston moves down and causes a pressure on the receiving piston which moves up. The floating lever is pushed up by the receiving piston and the lever moves the pilot valve plunger up to close the control port. The output terminal shaft and power piston movement is stopped.

A change to the speed setting of the governor will give the same governor movements as an increase or decrease in load.

UG8 Lever Governor

A lever on the speed adjustment shaft is used to change the engine speed. The speed adjustment shaft moves the speeder plug up and down to change the force of the speeder spring.

This governor is equipped with speed droop, however, it must be adjusted inside the governor.


UG8 LEVER GOVERNOR

UG8 Dial Governor

The synchronizer is used to change engine speed. The speed setting motor on the top of the governor can also be used to change engine speed. Either control turns the speeder plug which moves up or down and changes the force of the speeder spring. The synchronizer indicator gives an indication of the number of turns the synchronizer has moved.

The load limit control is used to control the amount of travel of the output terminal shaft. The control can be used to stop the engine if the knob is turned to zero.


NOTICE

Do not move the governor linkage in the increase fuel direction until the load limit control is moved to the maximum position.


The speed droop control is used to adjust the amount of speed droop from zero to one hundred percent. Speed droop is the difference between no load high idle rpm and full load rpm. This difference in rpm divided by the full load rpm and multiplied by 100 is the percent of speed droop.


UG8 DIAL GOVERNOR
1. Speed droop knob. 2. Synchronizer knob. 3. Load limit knob. 4. Synchronizer indicator.

Zero speed droop is used on a single system engine, such as a standby generator set. Speed droop higher than zero permits a load to be divided between two or more engines connected to the same load.

Pierce Output Shaft Governor

Output shaft governor (2) is driven by a flexible cable assembly (1) which connects to the governor drive mechanism on the torque converter. Output shaft governor (2) and hydraulic servo mechanism are connected by means of an adjustable link (9).


OUTPUT SHAFT GOVERNOR AND HYDRAULIC SERVO MECHANISM
1. Flexible drive cable. 2. Output shaft governor. 3. Terminal lever. 4. Rocker shaft. 5. Rate adjusting screw. 6. Speed change lever. 7. Governor spring. 8. Bumper screw. 9. Link. 10. Lever. 11. Lever. 12. Low speed adjusting screw. 13. High speed adjusting screw. 14. Bracket.

The output shaft governor acts as an "assistant operator," automatically reducing engine speed, which in turn reduces converter output shaft speed whenever the load on the converter output shaft decreases. Thus, it acts as a speed limiting device by preventing the output shaft and drive equipment from suddenly overspeeding. This also relieves the operator of making speed adjustments through the engine governor.

The torque converter output shaft maximum speed is either a high speed setting or a low speed setting, which is determined by changing the position of speed change lever (6), normally by remote control. High speed screw (13) determines the maximum speed for the high speed setting, and low speed screw (12) determines the maximum low speed setting. In other words, for either setting there is a predetermined maximum speed which the output shaft cannot exceed.

The operation of the governor is the same as most rotating weight-type governors. The governor operates only when the torque converter output shaft attempts to exceed a predetermined maximum speed. This speed is determined by the amount of tension placed on governor spring (7). On a variable speed governor, the spring tension is controlled by rate adjusting screw (5) and the position of the speed change lever. Increasing the spring tension increases the maximum speeds.

When the output shaft speed approaches the predetermined governed speed setting, weights (15) are forced out moving thrust sleeve (17) and bearing assembly (18) against the rocker yoke (19). As the output shaft speed reaches the predetermined governor speed setting, the force of the weights overcomes the force of the governor spring and the rocker yoke is moved, rotating the rocker shaft (4). Linkage attached to the rocker shaft overrides the diesel engine governor and reduces engine speed which in turn reduces converter output shaft speed. As the rocker yoke moves outward, it contacts small bumper spring (16) in the end of the governor body, which dampens oscillation of the yoke preventing erratic governor control. A bumper screw positions the bumper spring.

As torque converter output shaft speed drops below the maximum governed speed limit, the force exerted by the output shaft governor weights is reduced. Since the governor is then no longer effective, the diesel engine governor takes over full engine control and increases engine speed toward its full governed speed.

The terminal lever (3) mounted on the rocker shaft is connected to the hydraulic servo mechanism by the adjustable link (9) and actuating lever (10). Any movement of the rocker shaft is thus transmitted to the hydraulic servo mechanism.


OUTPUT SHAFT GOVERNOR OPERATION
15. Weight. 16. Bumper spring. 17. Thrust sleeve. 18. Bearing assembly. 19. Rocker yoke.

The hydraulic servo mechanism consists essentially of a servo piston (24), control valve and the necessary connecting linkage. The piston is connected to the actuating lever by link (21), lever (22) and shaft (20), and fits into the cylinder bore.

Oil, delivered from the engine oil pump, flows into the servo mechanism and normally flows through the piston, valve and back to the crankcase. When the output shaft governor takes effect, due to an increase in the torque converter output shaft speed, the governor linkage moves the control valve in the piston. The flow of oil through the piston is blocked and results in an oil pressure build-up. This pressure moves the piston to follow the movement of the valve. This movement continues until the piston ports are uncovered and oil flows through the piston once again.


GOVERNOR SERVO MECHANISM
20. Shaft. 21. Link. 22. Lever. 23. Shaft. 24. Piston. 25. Cam.

The piston movement is transmitted to cam (25), shaft (23) and the governor linkage, and in turn decreases the amount of fuel being delivered to the engine.

When the load on the output shaft is increased, the output shaft speed is reduced and the force exerted by the output shaft governor weights decreases. The force exerted by the output shaft governor spring then overcomes the force exerted by the weights and the actuating linkage moves the servo mechanism valve into the piston. The movement of the valve into the piston uncovers dump ports and allows oil to flow unrestricted through the servo mechanism. The valve and piston are inactive and then the diesel engine governor takes over full control of the engine and the fuel rack moves in the direction of increased fuel, increasing engine speed to its full governed speed.

The whole operation sequence of the torque converter governor overriding the diesel engine governor and then relinquishing control again to the engine governor occurs each time the load variations are severe enough to permit the output shaft speed to increase or decrease and activate the output shaft governor.

Woodward SGT Governor

The SGT Governor for the torque converter has two speed droop governors assembled in a single housing so that either governor can control fuel to the engine. One governor is operated by the engine. The other governor is operated by a flexible cable from the torque converter.


WOODWARD SGT GOVERNOR
1. Fuel control lever. 2. High idle screw for the torque converter governor. 3. Speed adjusting lever. 4. High idle screw for the engine governor.

The two governors use a single servo piston to move the fuel system linkage. The actions of the speeder springs in the governor, which are operated by the servo piston, are separate so that adjustment of either speed droop can be made for control of engine and torque converter speed. Oil from the pilot valve of the engine governor is moved to and from the governor servo piston by going through the piston valve of the converter governor.

When the torque converter speed is less than the value given in the specifications, the pilot valve for the converter governor gives a straight through oil passage from the engine governor to the servo piston because the force from the flyweights of the converter governor is not enough to lift the pilot valve. Under this condition the fuel is under control of the engine governor only. At an increase in the engine speed setting or a decrease in the load, the speed of the torque converter will go to the maximum speed adjustment for the converter governor. At this point, the pilot valve for the converter governor will be lifted to close the passage between the engine governor and the servo piston and the converter governor will take control. A decrease in load or increase in engine speed setting will now cause no increase in torque converter speed because the pilot valve for the converter governor will be lifted to release oil from the servo piston and the converter governor will control fuel flow to the engine.

Governor Air Actuators

The governor air actuator gives remote control of variable speed for the engine. The actuator operates on air pressure. Air pressure on the cup in the actuator moves the plunger, spring and rod. This motion controls the governor through the linkage.


2N6006 AIR ACTUATOR
1. Linkage.

Three types of actuators are available. The 2N6006 Actuator connects directly to the governor control shaft through linkage (1). Inspection or replacement of the diaphragm without changing the adjustment of the high or low idle speeds or the spring preload is possible. See REMOVE AND INSTALL DIAPHRAGM in DISASSEMBLY AND ASSEMBLY. THE 1N9318 and 7L135 Actuators control the governor through the hand control lever (2) and cross shaft linkage. These actuators have an adjustment for spring preload only.


1N9318 and 7L135 AIR ACTUATORS
2. Hand control lever for the governor.

3N9124 Air Actuator for UG8 Lever Governor is attached directly to the governor. One linkage rod connects the actuator to the governor speed control lever.


3N9124 AIR ACTUATOR

Power Take-Off Clutches


POWER TAKE-OFF CLUTCH (Typical Illustration)
1. Ring. 2. Driven discs. 3. Link assemblies. 4. Lever. 5. Key. 6. Collar assembly. 7. Nut. 8. Yoke assembly. 9. Hub. 10. Plates. 11. Output shaft.

Power take-off clutches (PTO's) are used to send power from the engine to accessory components. For example, a PTO can be used to drive an air compressor or a water pump.

The PTO is driven by a ring (1) that has spline teeth around the inside diameter. The ring can be connected to the front or rear of the engine crankshaft by an adapter.

NOTE: On some PTO's located at the rear of the engine, ring (1) is a part of the flywheel.

The spline teeth on the ring engage with the spline teeth on the outside diameter of driven discs (2). When lever (4) is moved to the ENGAGED position, yoke assembly (8) moves collar assembly (6) to the right. The collar assembly is connected to four link assemblies (3). The action of the link assemblies will hold the faces of drive discs (2), drive plates (10) and hub (9) tight together. Friction between these faces permits the flow of torque from ring (1), through driven discs (2), to plates (10) and hub (9). Spline teeth on the inside diameter of the driven discs drive the hub. The hub is held in position on the output shaft (11) by a taper, nut (7) and key (5).

NOTE: A PTO can have from one to three driven discs (2) with a respective number of plates.

When lever (4) is moved to the NOT ENGAGED position, yoke assembly (8) moves collar assembly (6) to the left. The movement of the collar assembly will release link assemblies (3). With the link assemblies released there will not be enough friction between the faces of the clutch assembly to permit a flow of torque.

Shutoff And Alarm System Components

Oil Pressure Switch

Micro Switch Type

The oil pressure switch is used to give protection to the engine from damage because of low oil pressure. When oil pressure lowers to the pressure specifications of the switch, the switch closes and activates the rack shutoff solenoid.

On automatic start/stop installations, this switch closes to remove the starting system from the circuit when the engine is running with normal oil pressure.

This switch for oil pressure can be connected in a warning system for indication of low oil pressure with a light or horn.

As pressure of the oil in bellows (6) becomes higher, arm (4) is moved against the force of spring (3). When projection (10) of arm (4) makes contact with arm (9), pressure in the bellows moves both arms. This also moves button (8) of the micro switch to activate the micro switch.


OIL PRESSURE SWITCH (Micro Switch Type)
1. Locknut. 2. Adjustment screw. 3. Spring. 4. Arm. 5. Spring. 6. Bellows. 7. Latch plate. 8. Button for micro switch. 9. Arm. 10. Projection of arm.

Some of these switches have a "Set For Start" button. When the button is pushed in, the micro switch is in the START position. This is done because latch plate (7) holds arm (9) against button (8) of the micro switch and the switch operates as if the oil pressure was normal. When the engine is started, pressure oil flows into bellows (6). The bellows move arm (4) into contact with latch plate (7). The latch plate releases the "Set For Start" button and spring (5) moves it to the RUN position. This puts the switch in a ready to operate condition.

Earlier Type Switch

Early type switches for oil pressure have a control knob (1). The knob must be turned (reset) every time the engine is stopped. Turn the knob counterclockwise to the OFF position before the engine is started. The knob will move to the RUN position when the oil pressure is normal.


OIL PRESSURE SWITCH (Earlier Type)
1. Control knob.

Pressure Switch

These type pressure switches are used for several purposes and are available with different specifications. They are used in the oil system and in the fuel system. One use of the switch is to open the circuit between the battery and the rack shutoff solenoid after the oil pressure is below the pressure specifications of the switch. It also closes when the engine starts.

Another use of the switch is to close and activate the battery charging circuit when the pressure is above the pressure specification of the switch. It also disconnects the circuit when the engine is stopped.


PRESSURE SWITCH

Some switches of this type have three terminal connections. They are used to do two operations with one switch. They open one circuit and close another with the single switch.

Water Temperature Contactor Switch

The contactor switch for water temperature is installed in the water manifold. No adjustment to the temperature range of the contactor can be made. The element feels the temperature of the coolant and then operates the micro switch in the contact when the coolant temperature is too high, the element must be in contact with the coolant to operate correctly. If the cause for the engine being too hot is because of low coolant level or no coolant, the contactor switch will not operate.

The contactor switch is connected to the rack shutoff solenoid to stop the engine. The switch can also be connected to an alarm system. When the temperature of the coolant lowers to the operating range, the contactor switch opens automatically.


WATER TEMPERATURE CONTACTOR SWITCH

Shutoff Solenoid

A shutoff solenoid changes electrical input into mechanical output. They are used to move the fuel rack to a no fuel position or to move a valve assembly in the air inlet pipe to a closed position. This stops the engine.

The shutoff solenoid can be activated by any one of the many sources. The most usual are: water temperature contactor, oil pressure switch, overspeed switch and remote manual control switch.


RACK SHUTOFF SOLENOID (Typical Illustration)

Circuit Breaker

The circuit breaker gives protection to an electrical circuit. Circuit breakers are rated as to how much current they will permit to flow. If the current in a circuit gets too high it will cause heat in disc (3). Heat will cause distortion of the disc and contacts (2) will open. No current will flow in the circuit.


NOTICE

Find and correct the problem that caused the circuit breaker to open. This will help prevent damage to the circuit components from too much current.


An open circuit breaker will close (reset) automatically when it becomes cooler.


CIRCUIT BREAKER SCHEMATIC
1. Disc in open position. 2. Contacts. 3. Disc. 4. Circuit terminals.

Shutoff Valve For Water Temperature

The shutoff valve for water temperature is connected in an oil line from the mechanical shutoff. Thermostat assembly (4) is in contact with the engine coolant. When the water temperature is normal, spring (1) holds ball (5) on its seat which stops the flow of oil. This lets the oil pressure become normal in the shutoff. High water temperature above the setting of the valve will cause the thermostat assembly to move stem (3). This will move ball (5) off its seat to let the oil pressure in the shutoff go back to the engine oil sump through outlet port (6). The low oil pressure causes the shutoff to stop the engine.


SHUTOFF VALVE FOR WATER TEMPERATURE
1. Spring. 2. Inlet port. 3. Stem. 4. Thermostat assembly. 5. Ball. 6. Outlet port.

Contactor Switch For Overspeed

The contactor switch for overspeed is installed on the tachometer drive on the front of the engine. It gives protection to the engine from running too fast.

The switch is connected to the rack shutoff solenoid to stop the engine. After the engine is stopped because of an overspeed condition, push the button (1) to open the switch and permit the starting of the engine.


CONTACTOR SWITCH FOR OVERSPEED
1. Button.

Hydra-Mechanical Shutoff

There are four hydra-mechanical shutoffs used on V-8, V-12 and V-16 engines. The 3N5760 Shutoff is used on V-8 and V-12 engines with rated engine speeds of 1001 thru 1300 rpm. The 5N1978 Shutoff is used on V-8 and V-12 engines with a rated engine speed of 900 thru 1000 rpm. The 5N5993 Shutoff is used on V-8, V-12 and V-16 engines with a rated speed of 900 thru 1000 rpm. The 5N5994 Shutoff is used on V-8, V-12 and V-16 engines with rated speeds of 1001 thru 1300 rpm. There is a part number identification plate attached to each unit.

NOTE: V-8 and V-12 engines have a manually operated valve located at the starter control to prevent engine shutdown when a warm engine is started. When the valve is activated at start-up, a valve in the rack circuit opens, and prevents rack actuator from moving. When the engine starts and the engine oil pressure is normal, the valve is released and the rack circuit is returned to normal operation.

Hydra-Mechanical Shutoff (5N5993 and 5N5994)

The hydra-mechanical shutoff gives protection for low oil pressure, high coolant temperature, and engine overspeed. The shutoff also has a manual control to stop the engine. The shutoff uses lubrication oil from the engine and has an oil pump to give pressure to the shutoff system.

The fuel rack shutoff will move the rack to the fuel off position with either low oil pressure or high coolant temperature. Both the fuel rack and inlet air shutoffs will activate when the engine overspeeds or if the manual control is used. The fuel rack shutoff will reset automatically but the inlet air shutoff must be manually reset.

The hydra-mechanical shutoff gives two ranges of engine oil pressure protection. As engine speed increases, the minimum oil pressure needed also increases. At low engine speed, the shutoff will activate at a minimum oil pressure of 20 psi (140 kPa). At high engine speeds, the shutoff will activate at a minimum oil pressure of 30 psi (205 kPa).

A flyweight controlled, speed sensing spool valve (1) is used to feel engine speed. This provides the two ranges of oil pressure protection and overspeed protection. The speed sensing spool valve (1) is moved by flyweights (2) which are turned by drive shaft (3). The drive shaft is connected to the engine oil pump drive shaft. When engine speed increases, the flyweights move out and push the speed sensing spool valve.


HYDRA-MECHANICAL SHUTOFF
1. Speed sensing spool valve. 2. Flyweights. 3. Drive shaft.

Make reference to the schematics for the explanation that follows of the hydra-mechanical shutoff hydraulic circuits. The hydraulic circuits inside the heavy dashed lines are in the basic shutoff group. The components outside the heavy dashed lines are lines, valves, and actuators located on the engine away from the shutoff unit.

Oil Pressure Protection


SCHEMATIC NO. 1
1. Speed sensing spool valve. 4. Oil pump. 5. Oil pump relief valve. 6. Rack sequence valve. 7. Air inlet sequence valve. 8. Air inlet shutoff actuator. 9. Pilot operated, two way valve. 10. Diverter valve. 11. Fuel rack actuator. 12. Fuel rack orifice. 13. Low range oil pressure sensing valve. 14. High range oil pressure sensing valve. 15. Selector valve. 16. Thermostatic pilot valve. 17. Engine oil pressure orifice. 18. Manual shutoff valve.

Make reference to schematic No. 1

At approximately 70% of engine full load speed, the oil pressure protection changes from low range to high range. This change is made with the use of valves (13), (14), (15) and (1). Engine oil pressure goes to valves (13) and (14). Valves (13) and (14) are normally closed. The valves will open only if the engine oil pressure is more than the force of the spring behind the valves. Valve (13) is for low speed range protection and will open if engine oil pressure is more than 20 psi (140 kPa). Valve (14) is for high speed range protection and will open if engine oil pressure is more than 30 psi (205 kPa). Selector valve (15) is normally open and is operated by pilot oil pressure from valve (1).

Low Speed Range (Normal Operation)

Make reference to schematic No. 1

Oil goes from oil pump (4) to rack sequence valve (6). Valve (6) keeps oil pressure at the start of the rack circuit at 110 psi (760 kPa). The remainder of the oil is sent to air inlet sequence valve (7), air inlet shutoff actuators (8), and pilot operated two way valve (9), and then to the sump. The rack circuit oil goes through fuel rack orifice (12), and through valves (13) and (15) and then back to the sump through pilot operated two way valve (9).

Low Speed Range (Low Oil Pressure)


SCHEMATIC NO. 2
10. Diverter valve. 11. Fuel rack actuator. 12. Fuel rack orifice 13. Low range oil pressure sensing valve.

Make reference to schematic No. 2.

If the engine oil pressure goes below 20 psi (140 kpa), valve (13) will close and keep rack circuit oil from the sump. The pressure drop across fuel rack orifice (12) goes to zero and pilot oil pressure goes to diverter valve (10). Valve (10) moves and oil pressure goes to fuel rack actuator (11) which moves the fuel rack to the shutoff position.

High Speed Range (Normal Operation)


SCHEMATIC NO. 3
1. Speed sensing spool valve. 9. Pilot operated, two way valve. 13. Low range oil pressure sensing valve. 14. High range oil pressure sensing valve. 15. Selector valve.

Make reference to schematic No. 3.

When engine speed increases to approximately 70% of full load speed, speed sensing spool valve (1) will move to give pilot oil pressure to selector valve (15). This will close valve (15) and remove the effect of valve (13) from the circuit. The oil flow in the rack circuit is the same as for the low speed range except that oil must go through valve (14) to return to sump through valve (9) because valve (15) is closed.

High Speed Range (Low Oil Pressure)


SCHEMATIC NO. 4
10. Diverter valve. 11. Fuel rack actuator. 12. Fuel rack orifice. 14. High range oil pressure sensing valve.

Make reference to schematic No. 4.

If the engine oil pressure goes below 30 psi (205 kPa) valve (14) will close and keep rack circuit oil from the sump. The pressure drop across fuel rack orifice (12) goes to zero and pilot oil pressure goes to diverter valve (10). Valve (10) moves and oil pressure goes to fuel rack actuator (11) which moves the fuel rack to the shutoff position.

High Coolant Temperature Protection


SCHEMATIC NO. 1
1. Speed sensing spool valve. 4. Oil pump. 5. Oil pump relief valve. 6. Rack sequence valve. 7. Air inlet sequence valve. 8. Air inlet shutoff actuator. 9. Pilot operated, two way valve. 10. Diverter valve. 11. Fuel rack actuator. 12. Fuel rack orifice. 13. Low range oil pressure sensing valve. 14. High range oil pressure sensing valve. 15. Selector valve. 16. Thermostatic pilot valve. 17. Engine oil pressure orifice. 18. Manual shutoff valve.

Make reference to schematic No. 1.

Thermsotatic pilot valve (16) is normally closed and is installed in the jacket water system. When the engine coolant temperature gets to 210° F (99° C) valve (16) will open. Engine oil pressure from engine oil pressure orifice (17) will go to the sump. With no oil pressure, valves (13 and 14) will close and the engine will shut down the same as with low oil pressure.

Overspeed Protection

If the engine overspeeds to a speed 18% above full load speed the shutoff control will activate and shut off both the fuel and air supply to the engine. The air inlet shutoff must be manually reset before the engine is started again.

Overspeed Circuit (Normal Operation)

Make reference to schematic No. 1

Oil goes from oil pump (4) to rack sequence valve (6). Valve (6) keeps oil pressure at the start of the rack circuit at 110 psi (760 kPa). The remainder of the oil goes to air inlet sequence valve (7) and to air inlet shutoff actuators (8). Valve (7) keeps the oil pressure at the start of the air inlet circuit at 15 psi (105 kPa). The remainder of the oil goes through valve (9), which is normally open, to the sump.

NOTE: Low oil pressure or high coolant temperature conditions do not change the oil flow in the air inlet circuit.

Overspeed Circuit (Overspeed condition)


SCHEMATIC NO. 5
1. Speed sensing spool valve. 7. Air inlet sequence valve. 8. Air inlet shutoff actuator. 9. Pilot operated, two way valve. 11. Fuel rack actuator.

Make reference to schematic No. 5.

When the engine gets to an overspeed condition, speed sensing spool valve (1) moves and sends pressure oil to valve (9), and to the spring side of air inlet sequence valve (7). The oil pressure will cause valves (7 and 9) to close and will not let the oil in the air inlet circuit return to the sump. Oil pressure in the air inlet circuit increases. Air inlet shutoff actuators (8) will move and release the valve plates in the inlet manifold to shut off the air supply to the engine.

Oil pressure to valve (9) will also not let rack circuit oil return to the sump. With the increase in oil pressure in the rack circuit, fuel rack actuator (11) is moved in the same way as for a low oil pressure condition.

Manual Shutoff


SCHEMATIC NO. 6
1. Speed sensing spool valve. 7. Air inlet sequence valve. 8. Air inlet shutoff actuator. 9. Pilot operated, two way valve. 11. Fuel rack actuator. 18. Manual shutoff valve.

Make reference to schematic No. 6.

The manual operation of manual shutoff valve (18) will shut off the fuel and air to the engine.

NOTE: The manual shutoff valve is to be used only for an emergency and not for normal engine shutdown.

Manual shutoff valve (18) is connected in series with speed sensing spool valve (1). When valve (18) is moved to the shutoff position, pressure oil is sent through valve (1) to air inlet sequence valve (7), and pilot valve (9). Fuel rack actuator (11) and air inlet actuators (8) are now activated the same as for an overspeed condition.

Hydra-Mechanical Shutoff (3N5760 and 5N1978)


HYDRA-MECHANICAL SHUTOFF
1. Speed sensing spool valve. 2. Flyweights. 3. Drive shaft.

The hydra-mechanical shutoff gives protection for low oil pressure, high coolant temperature, and engine overspeed. The shutoff also has a manual control to stop the engine. The shutoff uses lubrication oil from the engine and has an oil pump to give pressure to the shutoff system.

The fuel rack shutoff will move the rack to the fuel off position with either low oil pressure or high coolant temperature. Both the fuel rack and inlet air shutoffs will activate when the engine overspeeds or if the manual control is used. The fuel rack shutoff will reset automatically but the inlet air shutoff must be manually reset.

The hydra-mechanical shutoff gives two ranges of engine oil pressure protection. As engine speed increases, the minimum oil pressure needed also increases. At low engine speed, the shutoff will activate at a minimum oil pressure of 20 psi (140 kPa). At high engine speeds, the shutoff will activate at a minimum oil pressure of 30 psi (205 kPa).

A flyweight controlled, speed sensing spool valve (1) is used to feel engine speed. This provides the two ranges of oil pressure protection and overspeed protection. The speed sensing spool valve (1) is moved by flyweights (2) which are turned by drive shaft (3). The drive shaft is connected to the engine oil pump drive shaft. When engine speed increases, the flyweights move out and push the speed sensing spool valve.

Make reference to the schematics for the explanation that follows of the hydra-mechanical shutoff hydraulic circuits. The hydraulic circuits inside the heavy dashed lines are in the basic shutoff group. The components outside the heavy dashed lines are lines, valves, and actuators located on the engine away from the shutoff unit.

Oil Pressure Protection


SCHEMATIC NO. 1
1. Speed sensing spool valve. 4. Oil pump. 5. Oil pump relief valve. 6. Rack sequence valve. 7. Air inlet sequence valve. 8. Air inlet shutoff actuator. 9. Pilot operated two way valve. 10. Diverter valve. 11. Fuel rack actuator. 12. Fuel rack orifice. 13. Interface valve. 14. Low range oil pressure sensing valve. 15. High range oil pressure sensing valve. 16. Selector valve. 17. Thermostatic pilot valve. 18. Engine oil pressure orifice. 19. Manual shutoff valve.

Make reference to schematic No. 1

At approximately 70% of engine full load speed, the oil pressure protection changes from low range to high range. This change is made with the use of valves (14), (15), (16) and (1). Engine oil pressure goes to valves (14 and 15). Valves (14 and 15) are normally closed. The valves will open only if the engine oil pressure is more than the force of the spring behind the valves. Valve (14) is for low speed range protection and will open if engine oil pressure is more than 20 psi (140 kPa). Valve (15) is for high speed range protection and will open if engine oil pressure is more than 30 psi (205 kPa). Selector valve (16) is normally open and is operated by pilot oil pressure from valve (1).

Low Speed Range (Normal Operation)

Make reference to schematic No. 1.

Oil goes from oil pump (4) to rack sequence valve (6). Valve (6) keeps oil pressure at the start of the rack circuit at 65 psi (450 kPa). The remainder of the oil is sent to air inlet sequence valve (7), air inlet shutoff actuators (8), and pilot operated two way valve (9), and then to the sump. The rack circuit oil goes through fuel rack orifice (12), interface valve (13) and through valves (14 and 16) and then back to the sump.

Low Speed Range (Low Oil Pressure)


SCHEMATIC NO. 2
10. Diverter valve. 11. Fuel rack actuator. 12. Fuel rack orifice. 14. Low range oil pressure sensing valve.

Make reference to schematic No. 2.

If the engine oil pressure goes below 20 psi (140 kPa), valve (14) will close and keep rack circuit oil from the sump. The pressure drop across fuel rack orifice (12) goes to zero and pilot oil pressure goes to diverter valve (10). Valve (10) moves and oil pressure goes to fuel rack actuator (11) which moves the fuel rack to the shutoff position.

High Speed Range (Normal Operation)


SCHEMATIC NO. 3
1. Speed sensing spool valve. 14. Low range oil pressure sensing valve. 15. High range oil pressure sensing valve. 16. Selector valve.

Make reference to schematic No. 3.

When engine speed increases to approximately 70% of full load speed, speed sensing spool valve (1) will move to give pilot oil pressure to selector valve (16). This will close valve (16) and remove the effect of valve (14) from the circuit. The oil flow in the rack circuit is the same as for the low speed range except that oil must go through valve (15) to return to sump because valve (16) is closed.

High Speed Range (Low Oil Pressure)


SCHEMATIC NO. 4
10. Diverter valve. 11. Fuel rack actuator. 12. Fuel rack orifice. 15. High range oil pressure sensing valve.

Make reference to schematic No. 4.

If the engine oil pressure goes below 30 psi (205 kPa) valve (15) will close and keep rack circuit oil from the sump. The pressure drop across fuel rack orifice (12) goes to zero and pilot oil pressure goes to diverter valve (10). Valve (10) moves and oil pressure goes to fuel rack actuator (11) which moves the fuel rack to the shutoff position.

High Coolant Temperature Protection


SCHEMATIC NO. 1
1. Speed sensing spool valve. 4. Oil pump. 5. Oil pump relief valve. 6. Rack sequence valve. 7. Air inlet sequence valve. 8. Air inlet shutoff actuator. 9. Pilot operated, two way valve. 10. Diverter valve. 11. Fuel rack actuator. 12. Fuel rack orifice. 13. Interface valve. 14. Low range oil pressure sensing valve. 15. High range oil pressure sensing valve. 16. Selector valve. 17. Thermostatic pilot valve. 18. Engine oil pressure orifice. 19. Manual shutoff valve.

Make reference to schematic No. 1.

Thermostatic pilot valve (17) is normally closed and is installed in the jacket water system. When the engine coolant temperature gets to 210° F (99° C) valve (17) will open. Engine oil pressure from engine oil pressure orifice (18) will go to the sump. With no oil pressure, valves (14 and 15) will close and the engine will shut down the same as with low oil pressure.

Overspeed Protection

If the engine overspeeds to a speed 18% above full load speed the shutoff control will activate and shut off both the fuel and air supply to the engine. The air inlet shutoff must be manually reset before the engine is started again.

Overspeed Circuit (Normal Operation)

Make reference to schematic No. 1.

Oil goes from oil pump (4) to rack sequence valve (6). Valve (6) keeps oil pressure at the start of the rack circuit at 65 psi (450 kPa). The remainder of the oil goes to air inlet sequence valve (7) and to air inlet shutoff actuators (8). Valve (7) keeps the oil pressure at the start of the air inlet circuit at 15 psi (105 kPa). The remainder of the oil goes through valve (9), which is normally open, to the sump.

NOTE: Low oil pressure or high coolant temperature conditions do not change the oil flow in the air inlet circuit.

Overspeed Circuit (Overspeed condition)


SCHEMATIC NO. 5
1. Speed sensing spool valve. 7. Air inlet sequence valve. 8. Air inlet shutoff actuator. 9. Pilot operated, two way valve. 11. Fuel rack actuator. 13. Interface valve.

Make reference to schematic No. 5.

When the engine gets to an overspeed condition, speed sensing spool valve (1) moves and sends pressure oil to interface valve (13), valve (9), and to the spring side of air inlet sequence valve (7). The oil pressure will cause valves (7 and 9) to close and will not let the oil in the air inlet circuit return to the sump. Oil pressure in the air inlet circuit increases and air inlet shutoff actuators (8) will move and release the valve plates in the inlet manifold to shut off the air supply to the engine.

Oil pressure to interface valve (13) will cause the valve to close and will not let rack circuit oil return to the sump. With the increase in oil pressure in the rack circuit, fuel rack actuator (11) is moved in the same way as for a low oil pressure condition.

Manual Shutoff


SCHEMATIC NO. 6
1. Speed sensing spool valve. 7. Air inlet sequence valve. 8. Air inlet shutoff actuator. 9. Pilot operated, two way valve. 11. Fuel rack actuator. 13. Interface valve. 19. Manual shutoff valve.

Make reference to schematic No. 6.

The manual operation of manual shutoff valve (19) will shut off the fuel and air to the engine.

NOTE: The manual shutoff valve is to be used only for an emergency and not for normal engine shutdown.

Manual shutoff valve (19) is connected in series with speed sensing spool valve (1). When valve (19) is moved to the shutoff position, pressure oil is sent through valve (1) to interface valve (13), air inlet sequence valve (7), and pilot valve (9). Fuel rack actuator (11) and air inlet actuators (8) are now activated the same as for an overspeed condition.

2301 Parallel Control System


2301 PARALLEL CONTROL BOX

The 2301 Parallel Control has two functions: exact engine speed and kilowatt load sharing. The system measures engine speed constantly and makes necessary corrections to the engine fuel setting through an actuator connected to the fuel system.

The engine speed is felt by a magnetic pickup. As the teeth of the flywheel go through the magnetic lines of force around the pickup an AC voltage is made. The ratio between the frequency of this voltage and the speed of the engine is directly proportional. An electric circuit inside the control box feels this AC voltage. In response it sends a DC control voltage, inversely proportional to engine speed, to the actuator.

The actuator is connected to the fuel system by linkage. It changes the electrical input from the control box to mechanical output that changes the engine fuel setting. For example, if the engine speed was more than the speed setting, the control box will decrease fuel to the engine.

Kilowatt load sharing between a group of engine driven generator sets is made possible by electric circuits in the control box. The load on each generator in the system is measured constantly by its control box. Loads are compared between control boxes through paralleling wires between all the units on the same bus. From the input of the paralleling wires the load sharing circuits make constant corrections to the control voltages sent to the actuators. This gives kilowatt load sharing.

The rated and low idle engine speeds are set with speed setting potentiometers. An optional remote speed trim potentiometer will give ± 4% speed setting adjustment. The ramp time potentiometer controls the amount of time it takes the engine to go from low idle to rated speed. An oil pressure switch is connected between terminals 14 and 15. This switch is normally open. When the engine oil pressure increases to 6.4 ± 2.7 psi (44 ± 19 kPa) the switch closes. This permits the control to accelerate the engine to rated speed. If the oil pressure decreases to 3.9 ± 3.3 psi (27 ± 23 kPa) the control will return the engine to low idle.


ACTUATOR


MAGNETIC PICKUP

A minimum fuel switch can be connected between terminals 22 and 23. This gives an optional method for shutdown. When this switch is closed the voltage output to the actuator is zero.

The gain and stability potentiometers control the response of the engine to a change in load. The gain potentiometer is used to decrease response time to a minimum. The stability potentiometer is used to get the best speed stability for the gain setting that is used.

The speed droop potentiometer controls the amount of speed droop. It can be set between 0 and 13%. Droop is necessary when paralleling with a utility bus or a unit with a hydra-mechanical governor.

The de-droop potentiometer gives compensation during isochronous operation for droop caused by component tolerances and outside electrical noise.

The load gain potentiometer is set so that the ratio between the actual kilowatt output and the rated kilowatt output of each unit in the system is the same.

The speed failsafe circuit will return the voltage output of the control to zero if the magnetic pickup signal has a failure. This will cause the actuator to move to the FUEL OFF position. Also the engine will not start if the magnetic pickup signal has a failure.

NOTE: Earlier arrangements will go to the maximum fuel position with loss of voltage to the actuator.

2301 Nonparallel Control System


NONPARALLEL CONTROL BOX

The 2301 Nonparallel Control gives exact engine speed control. The system measures engine speed constantly and makes necessary corrections to the engine fuel setting through an actuator connected to the fuel system.

The engine speed is felt by a magnetic pickup. As the teeth of the flywheel go through the magnetic lines of force around the pickup an AC voltage is made. The ratio between the frequency of this voltage and the speed of the engine is directly proportional. An electric circuit inside the control box feels the AC voltage. In response it sends a DC control voltage, inversely proportional to engine speed, to the actuator.

The actuator is connected to the fuel system by linkage. It changes the electrical input from the control box to mechanical output that changes the engine fuel setting. For example, if the engine speed was more than the speed setting, the control box will decrease its output and the actuator will decrease fuel to the engine.

The rated and low idle engine speeds are set with speed setting potentiometers. An optional remote speed trim potentiometer will give ± 6% speed setting adjustment. A capacitor can be used between terminals 15 and 16 to control the amount of time it takes the engine to go from low idle to rated speed. An oil pressure switch is connected between terminals 9 and 10. This switch is normally open. When the engine oil pressure increases to 6.4 ± 2.7 psi (44 ± 19 kPa) the switch closes. This permits the control to accelerate the engine to rated speed. If the oil pressure decreases to 3.9 ± 3.3 psi (27 ± 23 kPa) the control will return the engine to low idle.


ACTUATOR


MAGNETIC PICKUP

The gain and stability potentiometers control the response of the engine to a change in load. The gain potentiometer is used to decrease response time to a minimum. The stability potentiomter is used to get the best speed stability for the gain setting that is used.

A droop potentiometer can be connected between terminals 13, 14 and 15 to control the amount of speed droop. Droop is necessary when paralleling with a utility bus or a unit with a hydra-mechanical governor.

The speed failsafe circuit will return the voltage output of the control to zero if the magnetic pickup signal has a failure. This will cause the actuator to move to the FUEL OFF position. Also the engine will not start if the magnetic pickup signal has a failure.

NOTE: Earlier arrangements will go to the maximum fuel position with loss of voltage to the actuator.

Automatic Start/Stop System (Non-Package Generator Sets)


AUTOMATIC START/STOP SYSTEM SCHEMATIC (Hydraulic Governor)
1. Starter motor and solenoid. 2. Shutoff solenoid. 3. Fuel pressure switch. 4. Water temperature switch. 5. Oil pressure switch. 6. Overspeed contactor. 7. Battery. 8. Initiating relay (IR). 9. Shutdown relay (SR). 10. Auxiliary relay (AR). 11. Overcrank timer (OCT). 12. ON/OFF/STOP switch (SW2). 13. AUTOMATIC/MANUAL switch (SW1). 14. Terminal board (TS1).

An automatic start/stop system is used when a standby electric set has to give power to a system if the normal (commercial) power supply has a failure. There are three main sections in the system. They are: the automatic transfer switch, the cranking panel and the electric set.

Automatic Transfer Switch

The automatic transfer switch normally connects the 3-phase normal (commercial) power supply to the load. When the commercial power supply has a failure the switch will transfer the load to the standby electric set. The transfer switch will not transfer the load from commercial to emergency power until the emergency power gets to the rated voltage and frequency. The reason for this is, the solenoid that causes the transfer of power operates on the voltage from the standby electric set. When the normal power returns to the rated voltage and frequency and the time delay (if so equipped) is over, the transfer switch will return the load to the normal power supply.


AUTOMATIC TRANSFER SWITCH


AUTOMATIC START/STOP SYSTEM SCHEMATIC (2301 Control System)
1. Magnetic pickup. 2. Starter motor and solenoid. 4. Oil pressure switch 1 (OPS1). 5. Water temperature switch. 7. Overspeed switch. 8. Battery. 9. Initiating relay (IR). 10. Shutdown relay (SR1). 11. Auxiliary relay (AR). 12. Overcrank timer (OCT). 13. ON/OFF/STOP switch (SW2). 14. AUTOMATIC/MANUAL switch (SW1). 15. Terminal board (TS1). 16. EG-3P Actuator. 17. Oil pressure switch 2 (OPS2). 18. 2301 Control box.

Cranking Panel

The main function of the cranking panel is to control the start and shutoff of the electric set.


BASIC CRANKING PANEL
1. Indicator light. 2. Manual-Automatic switch. 3. ON-OFF-STOP switch.

LOCKOUT indicator light (1) will activate if, the engine does not start, or if a protection device gives the signal to shutoff during operation.

Switch (2) gives either AUTOMATIC or MANUAL starting. In the diagrams shown later this switch is called SW1. Switch (3) has three positions "ON", "OFF" and "STOP". This switch is called SW2 in the diagrams. Move SW2 (3) to ON and SW1 (2) to MAN to start the engine immediately. Move SW2 (3) to OFF on an electric set in operation to start the shutoff sequence. If the system is equipped with a time delay the engine will not stop immediately. When SW2 (3) is moved to the STOP position the engine stops immediately. The switch must be held in the STOP position until the engine stops. When the switch is released a spring returns it to the OFF position. With SW2 (3) in the ON position and SW1 (2) in the AUTO position the control is ready for standby operation.

There are several attachments that can be ordered for this panel. A description of how each one works and the effect it has on the operation of the standard system is given after the explanations of the standard system.

Electric Set

The components of the electric set are: the engine, the generator, the starting motor, the battery, the shut-off solenoid and signal switches on the engine. The electric set gives emergency power to drive the load.

An explanation of each of the signal components is given in separate topics.

Hydraulic Governor Application

The circuit illustrations that follow are basic schematics. DO NOT use them as complete wiring diagrams.

Components of the automatic start/stop system:


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: ENGINE STARTING


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: ENGINE STARTS


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: ENGINE DOES NOT START

AR
Auxiliary relay
CB
Circuit breaker
CR
Cranking relay
CT
Cranking terminate relay (part of OS)
D
Diode
IR
Initiating relay
MS
Magnetic switch
OCT
Overcrank timer
OPS
Oil pressure shut off switch
FPS
Fuel pressure switch
OS
Overspeed shut off switch
PS
Pinion solenoid
RR
Run relay
RS
Rack shut off switch
SM
Starting Motor
SR
Shutdown relay
SW1
Automatic/Manual switch
SW2
On/Off/Stop switch
WT
Water temperature shut off switch

Automatic Starting Operations

When emergency power is needed the initiating contactor closes. This energizes the initiating relay and the run relay. The current flow through the initiating relay contacts then energizes the magnetic switch, which energizes the pinion solenoid. The starting motor is now connected to the battery. The starting operation starts. At the same time the overcrank timer is energized and starts to run.

At 600 rpm the cranking terminate relay closes. Oil pressure causes oil pressure shutdown switch (OPS) to activate. The normally closed contacts open and the normally open contacts close. When oil pressure shutdown switch (OPS) activates, the auxiliary relay is energized and current flow to the magnetic switch and pinion solenoid is stopped. The starting operation then stops.

If the engine does not start in 30 seconds, the overcrank timer contact closes. This energizes the shutdown relay and the alarm light. The shutdown relay stops current flow to the initiating relay and the run relay. De-energizing the run relay also stops current flow to the auxiliary relay. When the shutdown relay is energized, the magnetic switch and the pinion solenoid are de-energized. The starting operation then stops. The shutdown relay also energizes the rack solenoid to move the fuel rack to the fuel OFF position. The shutdown relay is energized until switch (SW2) is manually turned to the OFF position.

Automatic Stopping Operations


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: SHUTDOWN BY PROTECTION COMPONENT

When the contacts for any of the shutdown switches close, the shutdown relay and the alarm light are energized. This de-energizes the initiating relay, run relay and auxiliary relay. The rack solenoid is energized to move the fuel rack to the fuel OFF position. A parallel circuit through the fuel pressure switch and the normally closed contact of the run relay is also completed to the rack solenoid. The shutdown relay is energized until switch (SW2) is manually turned to the OFF position.

When commercial power is started again, the initiating contactor opens. This de-energizes the initiating relay, the run relay and the auxiliary relay. Current then goes through the normally closed contact of the run relay to the rack solenoid. The rack solenoid is energized to move the fuel rack to the FUEL OFF position.


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: EMERGENCY POWER NOT NEEDED

Manual Starting Operation


CONTROL PANEL CONTROLS IN MANUAL POSITION: ENGINE STARTING

Switch (SW1), in the MANUAL position, removes the initiating contactor from the circuit. In the MANUAL position the initiating relay and the run relay are energized. This energizes the magnetic switch and the pinion solenoid. The starting motor is now connected to the battery. The starting operation starts. The overcrank timer is not in the circuit, so if the engine does not start, either switch (SW1) or (SW2) must be turned to another position to stop the starting operation. When the engine starts, the magnetic switch and the pinion solenoid are de-energized in the same way they are de-energized when the engine starts in the AUTOMATIC position.

Manual Stopping Operation


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: MANUAL SHUTDOWN

When switch (SW2) is moved to the STOP position, current flow is directly to the rack solenoid. The rack solenoid moves the fuel rack to the fuel OFF position. The initiating relay, run relay and auxiliary relay are de-energized. Switch (SW2) must be held in the STOP position until the engine stops.

2301 Control System Application

The circuit illustrations that follow are basic schematics. DO NOT use them as complete wiring diagrams.

Components of the automatic start/stop system:

AR
Auxiliary relay
CB
Circuit breaker
CR
Cranking relay
CT
Cranking terminate relay (part of OS)
D
Diode
IR
Initiating relay
MS
Magnetic switch
OCT
Overcrank timer
OPS1
Oil pressure shut off switch
OPS2
Oil pressure switch
OS
Overspeed shut off switch
PS
Pinion solenoid
SM
Starting Motor
SR1
Shutdown relay
SW1
Automatic/Manual switch
SW2
On/Off/Stop switch
WT
Water temperature shut off switch

Components of the 2301 control system:

2301 GOV.
2301 CONTROL
EG-3P ACT.
ACTUATOR
MP
Magnetic pickup
OPS2
Ramp switch for 2301 CONTROL

Automatic Starting Operations

When emergency power is needed, the initiating contactor closes. This energizes the initiating relay, the cranking relay, and connects the 2301 Control to the battery. The cranking relay energizes the magnetic switch and the pinion solenoid. The starting motor is now connected to the battery. The starting operation starts. At the same time the overcrank timer is energized and starts to run.


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: ENGINE STARTING

At 600 rpm the cranking terminate relay closes. Oil pressure switch (OPS2) closes at approximately 6.4 psi (44 kPa). This lets the 2301 Control signal the actuator to move from low idle to the desired rpm. Oil pressure also causes oil pressure shutdown switch (OPS1) to activate. The normally closed contacts open and the noramlly open contacts close. When oil pressure shutdown switch (OPS1) activates, the auxiliary relay is energized and current flow to the cranking relay stops. This de-energizes the magnetic switch and the pinion solenoid. The starting operation stops.

If the engine does not start in 30 seconds, the overcrank timer contact closes. This energizes the shutdown relay and the alarm light. The shutdown relay stops current flow to the initiating relay. The current flow is then stopped to the 2301 Control. The EG-3P Actuator moves the fuel rack to the FUEL OFF position. This also de-energizes the magnetic switch and the pinion solenoid. The starting operation stops. The shutdown relay is energized until switch (SW2) is manually turned to the OFF position.


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: ENGINE STARTS


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: ENGINE DOES NOT START

Automatic Stopping Operations

When the contacts for any of the shutdown switches close, the shutdown relay and the alarm light are energized. This de-energizes the initiating relay and the auxiliary relay. Current flow to the 2301 Control is stopped. The EG-3P Actuator will then move the fuel rack to the FUEL OFF position. The shutdown relay is energized until switch (SW2) is manually turned to the OFF position.

When commercial power is started again, the initiating contactor opens. This de-energizes the initiating relay and the auxiliary relay. Current flow to the 2301 Control is stopped. The EG-3P Actuator will then move the fuel rack to the FUEL OFF position.


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: SHUTDOWN BY PROTECTION COMPONENT


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: EMERGENCY POWER NOT NEEDED

Manual Starting Operation

Switch (SW1), in the MANUAL position, removes the initiating contactor from the circuit. In the MANUAL position the intiating relay is energized and current goes to the 2301 Control. The current flow through the initiating relay contacts also energizes the cranking relay. The cranking relay energizes the magnetic switch which in turn energizes the pinion solenoid. The starting motor is now connected to the battery. The starting operation starts. The overcrank timer is not in this circuit, so if the engine does not start, either switch (SW1) or (SW2) must be moved to another position to stop the starting operation. When the engine starts, the magnetic switch and the pinion solenoid are de-energized in the same way as they are de-energized when the engine starts in the Automatic Starting Operation.


CONTROL PANEL CONTROLS IN MANUAL POSITION: ENGINE STARTING

Manual Stopping Operation

When switch (SW2) is moved to the STOP position, current flow to the 2301 Control is stopped. The EG-3P Actuator will then move the fuel rack to the FUEL OFF position. The initiating relay and auxiliary relay are also de-energized. Switch (SW2) must be held in the STOP position until the engine stops.


CONTROL PANEL CONTROLS IN AUTOMATIC POSITION: MANUAL SHUTDOWN

Attachments For Cranking Panel

Separate Alarm Lights


SEPARATE ALARM LIGHTS

This attachment shows the reason for shutdown.

Cycle Cranking Timer

The cycle cranking timer has a cycle crank module (CC). It permits adjustment of the amount of time that the starting motor operates. It can be set for 30 seconds of constant operation to 5 cycles of 10 seconds of operation with a 10 second delay between each cycle of operation. When the cranking cycles set in the timer are completed, cycle crank module (CC) close the circuit to the overcrank relay (OCT).

Time Delay Relay

This attachment causes a 2 minute delay in the activation of the shutoff solenoid (RS) when the engine is automatically being stopped because of the return of (commercial) normal power.

The purpose of this time delay is to let the engine cool more slowly after running.

When the (commercial) normal power starts again, the initiating contactor (I) opens. This opens the circuit to the run relay (RR) and initiating relay (IR). The run relay (RR) has normally closed contacts which connect the oil pressure time delay switch (OPTD) with the time delay relay (TD). The oil pressure time delay switch (OPTD) is closed at this time. The time delay relay (TD) starts to measure time. After 2 more minutes of engine operation, the time delay relay (TD) activates. It closes its normally open contacts in the circuit between the oil pressure time delay switch (OPTD) and the shutoff solenoid (RS). Because the oil pressure time delay switch (OPTD) is closed, the circuit is now closed to the shutoff solenoid (RS). The shutoff solenoid (RS) activates. It moves the fuel rack to the FUEL OFF position. This makes the engine stop running.

If the (commercial) normal power stops before the engine stops turning, the engine can start running again immediately. This is because the initiating contactor (I) closes again. This closes the circuit to run relay (RR) and initiating relay (IR). The run relay (RR) activates and opens its normally closed contacts in the circuit with the time delay relay (TD). The time delay relay (TD) is now disconnectd so it opens its normally open contacts in the circuit with the shutoff solenoid (RS). The shutoff solenoid (RS) releases the fuel in the fuel injection pump. The governor controls the fuel supply to the engine. The governor gives the engine more fuel to make the speed increase to the correct speed for the engine.

If the initiating contactor (I) closes just as the engine stops turning the starting motor can activate almost immediately. This is because the oil pressure switch (OPS) is activated by engine oil pressure. When the engine stops running, the oil pressure decreases faster than the engine stops its motion. If the engine does not start running again because of the force of rotation of the flywheel, the engine oil pressure does not increase to activate the oil pressure switch (OPS). If the oil pressure switch (OPS) does not activate, the starting motor (SM) activates when the initating relay (IR) closes its contacts.


SCHEMATIC OF CONTROL PANEL (SHOWS ALL STANDARD ATTACHMENTS) (ALL COMPONENTS ARE SHOWN IN NORMAL CONDITIONS)

The components are:

AR
Auxiliary relay
BATT
Battery
CC
Cycle cranking timer
D1 and D2
Diodes
I
Initiating contactor
IR
Initiating relay
MS
Magnetic switch
OCT
Overcrank timer
OPS
Oil pressure shutdown switch
OPTD
Oil pressure time delay switch
RR
Run relay
RS
Rack shutoff solenoid
SM
Starting motor
SR-1,2,3
Shutdown relays
SW1
Automatic/Manual switch
SW2
On/Off/Stop switch
TD
Time delay relay
WT
Water temperature shutoff switch
*
Terminals in cranking panel

NOTE: Dotted lines show components outside the cranking panel.

Caterpillar Information System:

D379, D398, D399 INDUSTRIAL & MARINE ENGINES Contactor Switch For Oil Pressure
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Contactor Switch For Temperature
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Contactor Switch For Overspeed
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Electric Tachometer
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Pressure Switches
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Sending Units For Oil Pressure
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Sending Unit For Water Temperature
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Gauges For Water Temperature
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Gauges For Gear Oil Pressure
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Gauges For Engine Oil Pressure
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Mechanical Gauges
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Flexible Coupling (5L3395)
D379, D398, D399 INDUSTRIAL & MARINE ENGINES D379, D398I on Engine Attachments Testing And Adjusting
D379, D398, D399 INDUSTRIAL & MARINE ENGINES General Instructions
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Fuel Transfer Pump
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Fuel Priming Pump
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Water Temperature Regulators
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Expansion Tank (Marine Engines)
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Fuel Filter Housing
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Oil Filter Housing
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Sea Water Pump
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Vibration Damper (D398 and D399)
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Crankshaft Front Seal Ring And Thrower
D379, D398, D399 INDUSTRIAL & MARINE ENGINES Crankshaft Front Seal (Lip Type) And Wear Sleeve
Back to top
The names Caterpillar, John Deere, JD, JCB, Hyundai or any other original equipment manufacturers are registered trademarks of the respective original equipment manufacturers. All names, descriptions, numbers and symbols are used for reference purposes only.
CH-Part.com is in no way associated with any of the manufacturers we have listed. All manufacturer's names and descriptions are for reference only.