REHS1438 INSTALLATION G3520C

REHS1438-03March 2004

Special Instructioni02066887

Installation and Initial Start-UpProcedure for G3500C andG3500E EnginesSMCS Code: 1000

Electric Power GenerationG3516C (S/N: RWA1-Up; TJB1-Up;TJC1-Up; DKR1-Up)

G3516E (S/N: GHP1-Up; SLY1-Up)G3520C (S/N: GDB1-Up; GHC1-Up;GHE1-Up; B9P1-Up; CWW1-Up;CWY1-Up)

G3520E (S/N: HAL1-Up; GHM1-Up;GHR1-Up; SXY1-Up)

Table of ContentsIntroduction ........................................................... 1Requirements for the Electrical System ................ 2Grounding Practices ............................................. 2Welding on Electronically Controlled Engines ...... 3Service Tools ........................................................ 3Connecting Cat ET with the 171-4401Communication Adapter II ............................... 5

Terminal Box ......................................................... 6Junction Box ......................................................... 9Customer’s Wiring ................................................ 10Required Connections ....................................... 11Optional Connections ........................................ 14Unused Terminals ............................................. 16Wiring for the Emergency Stop Circuit .............. 17Wiring for the Gas Shutoff Valve (GSOV) ......... 19Wiring for Monitoring the Generator’s OutputPower .............................................................. 22Inputs for the Modes of Operation ..................... 23

Initial Start-Up Procedure ..................................... 25Adjusting the Governor ......................................... 27

IntroductionDo not perform any procedure in this SpecialInstruction until you read this information and youunderstand this information.

This Special Instruction provides the followinginformation for G3500C and G3500E Engines:

• Requirements for the electrical system

• Proper grounding practices

• Proper welding practices

• Required service tools

• Electrical components and electronic components

• Wiring connections and the correspondingfunctions that are available to the customer

• Initial start-up procedure

• Governor adjustment procedures

Reference: Information from the following sourceswill be needed for this Special Instruction:

• Data from a complete fuel analysis that is enteredinto Caterpillar Software, LEKQ6378, “MethaneNumber Program”

• The engine’s performance Data Sheet from theengine’s Technical Marketing Information (TMI)

• Operation and Maintenance Manual, SEBU7681

• Systems Operation/Testing and Adjusting,RENR5978

• Troubleshooting, RENR5944, “G3516C andG3516E Engines”

• Troubleshooting, RENR5979, “G3520C andG3520E Engines”

1

Requirements for the ElectricalSystemAll of the wiring must conform to all of the codes thatare applicable to the site. When you route the wiring,avoid acute bends and sharp edges. To protect thewiring harnesses, route the harnesses through metalconduit. A liquid tight conduit is recommended. Useproper support and alignment in order to avoid strainon the conduit.

Electrical power must be supplied to the junction boxthat serves as the main distribution panel for theengine control system. The engine control systemrequires a clean 24 VDC power supply that is capableof supplying 30 amperes of continuous power.

The maximum allowable AC ripple is 150 millivolts ACpeak to peak. For the wiring, the maximum allowablevoltage drop is 1 VDC from the power supply to anElectronic Control Module (ECM) or to an actuator.

The power supply for the engine control system mustbe separate from the power supply for the startingmotor.

Grounding PracticesProper grounding is necessary for optimum engineperformance and for reliability. Improper groundingwill result in electrical current paths that areuncontrolled and unreliable.

Uncontrolled electrical circuit paths can result indamage to main bearings, to crankshaft bearingjournal surfaces, and to aluminum components.Uncontrolled electrical circuit paths can also causeelectrical activity that may degrade the engineelectronics and communications.

• For the starting motor, do not attach the batterynegative terminal to the cylinder block.

• Use an electrical ground strap to connect allmetal cases that contain electrical components orelectronic components to the cylinder block.

• Do not connect the negative terminal from theelectrical power supply directly to the cylinderblock. Connect the negative terminal from theelectrical power supply to the negative terminal “−”on the engine mounted junction box.

• Ground the cylinder block with a ground strap thatis furnished by the customer. Connect this groundstrap to the ground plane.

• Use a separate ground strap to ground the batterynegative terminal for the control system to theground plane.

• Rubber couplings may connect the steel piping ofthe cooling system and the radiator. This causesthe piping and the radiator to be electricallyisolated. Ensure that the piping and the radiator arecontinuously grounded to the cylinder block. Useground straps that bypass the rubber couplings.

• Ensure that all grounds are secure and free ofcorrosion.

2

Welding on ElectronicallyControlled EnginesProper welding procedures are necessary in order toavoid damage to electronic controls. Perform weldingon the engine according to the following procedure.

1. Set the engine control to the “STOP” mode.

2. Turn OFF the fuel supply to the engine.

3. Disconnect the negative terminal from the battery.

4. Disconnect the engine’s electronic componentsfrom the wiring harnesses: ECM, throttle actuator,actuator for the turbocharger compressor’sbypass, fuel metering valve, and sensors.

5. Protect the wiring harnesses from welding debrisand/or from welding spatter.

NOTICEDo NOT use electrical components (ECM or ECMsensors) or electronic component grounding pointsfor grounding the welder.

6. Connect the welder’s ground cable directly tothe engine component that will be welded. Placethe clamp as close as possible to the weld inorder to reduce the possibility of welding currentdamage to the engine bearings, to the electricalcomponents, and to other engine components.

7. Use standard welding procedures to weld thematerials together.

Service ToolsThe tools that are listed in Table 1 are requiredin order to enable a service technician to performthe electrical installation procedures and the initialstart-up.

The Caterpillar Electronic Technician (Cat ET) isdesigned to run on a personal computer.

Cat ET can display the following information:

• Parameters

• Diagnostic codes

• Event codes

• Engine configuration

• Status of the monitoring system

Cat ET can perform the following functions:

• Perform diagnostic tests.

• Calibrate sensors.

• Download flash files.

• Set parameters.

Table 1 is a list of required service tools.

3

Table 1

Service Tools

Pt. No. Description Functions

N/A Personal Computer (PC) The PC is required for the use of Cat ET.

“JERD2124” Software Single user license for Cat ETUse the most recent version of this software.

“JERD2129” Software Data subscription for all engines

171-4400 (1) Communication Adapter Gp This group provides the communication between the PC and theengine.

7X-1414 Data Link Cable As This cable connects the communication adapter to the service toolconnector on the engine.

237-7547 Adapter Cable As This cable connects to the USB port on computers that are notequipped with a serial port.

8T-8726 Adapter Cable As This cable is for use between the jacks and the plugs of the sensors.

151-6320 Wire Removal Tool This tool is used for the removal of pins and of sockets fromDeutsch connectors and AMP connectors.

1U-5804 Crimp Tool This tool is used for work with electrical connectors.

146-4080 Digital Multimeter The multimeter is used for the testing and for the adjusting ofelectronic circuits.

7X-1710 Multimeter Probes The probes are used with the multimeter to measure voltage inwiring harnesses without disconnecting the harnesses.

156-1060 or156-1070

Emission Analyzer Tool This tool is used to measure the level of emissions in the engine’sexhaust. The 156-1060 measures the levels of four differentcompounds. The 156-1070 measures the levels of six differentcompounds. Either tool may be used.

(1) The 7X-1700 Communication Adapter Gp may also be used.

Note: For more information regarding the use of CatET and of the PC requirements for Cat ET, refer tothe documentation that accompanies your Cat ETsoftware.

4

Connecting Cat ET with the 171-4401Communication Adapter II

The engine’s battery supplies the communicationadapter with 24 VDC. Use the following procedure toconnect Cat ET to the engine’s control system.

1. Set the engine control to the OFF/RESET mode.

g01059043Illustration 1Left side view

(1) PC(2) 196-0055 Serial Cable or the 160-0141 Serial Cable(3) 171-4401 Communication Adapter II(4) 207-6845 Adapter Cable(5) 7X-1414 Data Link Cable(6) Terminal box

Note: Items (2), (3), and (4) are part of the 171-4400Communication Adapter Gp.

2. Connect cable (2) to the RS-232 serial port ofPC (1).

Note: If your PC is not equipped with a serial port,use the 237-7547 Adapter Cable As in order toconnect to the USB port. Connect one end of theadapter to the end of cable (2). Connect the otherend of the adapter to a USB port on the PC.

3. Connect cable (2) to communication adapter (3).

4. Connect cable (4) to communication adapter (3).

5. Connect cable (4) to cable (5).

6. Connect cable (5) to the service tool connectoron terminal box (6).

7. Set the engine control to the STOP mode. Theengine should be OFF.

If Cat ET and the communication adapterdo not communicate with the ECM, refer toTroubleshooting, “Electronic Service Tool Will NotCommunicate With ECM”.

20 Cylinder Engines

For 20 cylinder engines, if Cat ET displays“Duplicate Type on data link. Unable to Service”,check the harness code for the slave ECM.

The harness inside terminal box (6) has a jumperwire (harness code) that connects terminals J3-29and J3-60. The ECM that is connected to theharness reads the harness code. This allows theECM to operate as the slave ECM. The jumperwire must be connected in order for the Cat ETto communicate with the modules. The jumperwire must be connected in order for the engine tocrank. The jumper wire must remain connected inorder for the engine to run.

Check the continuity between terminals J3-29and J3-60. Verify that the jumper wire is in goodcondition. Make repairs, as needed.

5

Terminal BoxNote: The terminal box is designed to remainmounted on the engine. The mounting hardwareincludes isolators. Do not move the terminal box to aremote location. Moving the terminal box could resultin wiring problems and in reduction of the service lifeof the components inside the terminal box.

g01059049Illustration 2Rear view(6) Terminal box(7) Emergency stop button

Terminal box (6) contains the electronic controlmodules. Connectors on the back of the terminalbox connect the engine’s wiring harnesses tocomponents inside the terminal box. The ignitionharnesses are routed directly from each ECM to theignition transformers.

6

Illustration 3 shows the components that are inside ofthe terminal box of a 16 cylinder engine.

g01059113Illustration 3

Components inside the terminal box on a 16 cylinder engine(1) ECM(2) Ground strap for the ECM(3) ECM connectors J2/P2(4) ECM connectors J1/P1(5) Ignition harness

(6) J10/P10 connector for the terminatingresistor for the CAN data link

(7) Service tool connector J5 for Cat ET(8) J6 connector for the customer(9) J9 connector for the engine harness

(10) J7 connector for the engine harness(11) J8 connector for the detonation

sensors

Illustration 4 shows the components that are inside ofthe terminal box on a 20 cylinder engine.

7

g01060562Illustration 4Components inside the terminal box on a 20 cylinder engine

(1) Master ECM(2) Slave ECM(3) Ground strap for the master ECM(4) J3/P3 connectors for the slave ECM(5) Master ECM connectors J2/P2(6) J4/P4 connectors for the slave ECM(7) Master ECM connectors J1/P1

(8) Ground strap for the slave ECM(9) Ignition harness for the left bank(10) Ignition harness for the right bank(11) Service tool connector J5 for Cat ET(12) J10/P10 connectors for the

terminating resistor for the CAN datalink

(13) J6 connector for the customer(14) J9/P9 connectors for the engine

harness(15) J7/P7 connectors for the engine

harness(16) J8/P8 connectors for the detonation

sensors

8

Junction BoxThe junction box serves as the main distributionpanel for the engine’s electrical power. The junctionbox contains all of the circuit breakers for the engine.The junction box also contains the magnetic switchesfor the electric starting motors.

Illustration 5 shows the junction box.

g01059145Illustration 5The junction box is located on left side of the engine.(1) Junction box(2) 2.5 amp circuit breaker for the engine

control(3) 10 amp circuit breaker for the

customer

(4) 35 amp circuit breaker for the enginecontrol’s main power supply

(5) 2.5 amp circuit breaker for the startcommand from the ECM

(6) Positive terminal for the connection ofthe engine’s power supply

(7) Negative terminal for the connectionof the engine’s power supply

9

Customer’s WiringTo properly wire the engine for the requirements ofthe specific application, the customer must be awareof several inputs and outputs that are associatedwith the engine’s control system. The following listincludes some examples of the inputs and outputs:

• Emergency stop

• Electrical power supply for the control system

• Start-up and shutdown

• Engine speed and governing

• Status of engine operation

The 9X-7147 Connector Plug is available for thecustomer in order to fabricate a wiring harness tothe customer connector on the engine mountedterminal box. A 16 to 18 AWG size of wire may beused. The 9X-7147 Connector Plug mates with theJ6 connector on the back of the terminal box. Referto Illustration 6.


40−pin J6 connector

Note: The 40−pin connector is secured with aretaining bolt that is tightened to a torque of2.25 ± 0.25 N·m (20 ± 2.00 lb in).

Some of the wiring connections are required. Some ofthe wiring connections are optional. The connectionsthat are required are identified in Table 2. Theconnections that are optional are identified in Table 3.

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Required ConnectionsTable 2

40-Pin Connector J6Required Connections

Terminal Description Functions and Comments

10 Emergency stop

20 Digital return

Terminal 10 is provided as an option for a customer suppliedemergency stop button.

Terminal 10 must be connected to terminal 20 in order for theengine to run. If this circuit is open, the engine will not start.When this circuit is opened during operation, an emergencystop shutdown is activated:

If the ECM is controlling the gas shutoff valve, the ECM willde-energize the gas shutoff valve. The fuel is immediatelyshut off.

The ignition is immediately shut off.

For details, refer to “Wiring for the Emergency Stop Circuit”.

36 Digital return This terminal provides a ground for the following switchinputs from the customer. Some of the inputs are requiredand some of the inputs are optional.

Auto

Start/Run

Stop

Timing setting

On/Off grid

Driven equipment

Normal stop

Idle/rated input

21 Fuel control relay’s +Battery

31 Fuel control relay’s +Battery

The Gas Shutoff Valve (GSOV) may be controlled by theengine’s control system or by the customer’s equipment.

For details on these terminals, refer to “Wiring for the GasShutoff Valve (GSOV)”.

9 Driven equipment This input indicates when the driven equipment is ready foroperation. This input must be connected to terminal J6-36 inorder for the engine to run.

When this input is connected to terminal J6-36, the enginecan be started.

When this input is not connected to terminal J6-36, theengine will not crank.

An event code will be generated if this input is not connectedto terminal J6-36 within a period of time that can beprogrammed with Cat ET.

If the engine is running and this input is disconnected fromterminal J6-36, the ECM will immediately shut down theengine by removing the voltage from the GSOV. The fuelsupply is immediately shut off. The engine cooldown will notoccur.

(continued)

11

(Table 2, contd)



29 Start/Run

19 Stop

If these inputs are not wired correctly, the ECM will activate adiagnostic code.

These inputs are provided by the customer’s equipment. Theinputs control the engine’s mode of operation.

The transitions between the inputs must occur within 1/10second.

These inputs must return through terminal J6-36.

When terminal 29 is grounded to terminal J6-36, the normalsequence for start-up is initiated. After start-up, the enginewill continue to run.

If the engine is running and terminal 19 is grounded toterminal J6-36, the sequence for a normal shutdown isinitiated. If the cooldown is programmed, the engine operatesfor the cooldown period prior to shutdown.

40 Idle/Rated Input This input must be grounded to terminal J6-36 in order for theengine to run at rated speed.

When this input is open, the engine will run at the idle speedthat is programmed with Cat ET.

When the engine oil pressure is greater than the setpoint forthe engine speed and this terminal is grounded to terminalJ6-36, the engine will run at rated speed.

30 Normal stop This input must be grounded to terminal J6-36 in order forthe engine to run.

The grounding of terminal 19 to terminal J6-36 isrecommended for normal shutdown.

If this input is not grounded to terminal J6-36, the engine willnot crank. If the engine is running and the circuit is opened,the engine will shut down.

If the ECM is controlling the gas shutoff valve, the ECM willremove the voltage from the GSOV. The engine will shutdown. The cooldown does not operate.

If the customer’s equipment is controlling the GSOV, thecustomer’s equipment must remove the voltage from theGSOV. The engine will shut down. The cooldown does notoperate.

No diagnostic codes or event codes are provided for thisinput.

Because the cooldown will not operate for this input, thisinput is not recommended for normal shutdown.

(continued)

12

(Table 2, contd)



4 Unswitched +Battery (2.5 amp)

14 Switched + Battery

These terminals provide the primary source of switchedelectrical power to the engine control system.

The unswitched 24 VDC is always available as an output atterminal 4 when the 2.5 amp circuit breaker in the junctionbox is switched ON. The output is intended for use by acustomer supplied engine control switch.

The engine control switch provides the 24 VDC throughterminal 14 to the following components during operation inthe Auto mode, in the Start/Run mode, and in the Stop mode:

Master ECM

Slave ECM (if equipped)

Integrated Temperature Sensing Module (ITSM)

Fuel metering valve

For more information on these terminals, refer to “Inputs forthe Modes of Operation”.

3 Kilowatt signal

13 Return

If the generator is equipped with an EMCP II+ system, theseterminals are not used.

These terminals are only required if the customer supplies awattmeter for monitoring of the generator’s output power.

For more information, refer to “Wiring for the Generator’sOutput Power”.

Desired Speed Input

The desired speed input may be supplied by a 0 to 5 V analog signal or by a 4 to 20 mA signal.

The method for the desired speed input must be selected with Cat ET.

5 +5 V for the speed potentiometer

25 Signal +

15 Return -

35 Shield

The ECM provides the +5 V supply to the potentiometer. Thepotentiometer provides the signal input for the desired speed.The signal input ranges from 0 to 5 volts.

Provide an input of 0 VDC for minimum high idle. Provide aninput of 5 VDC for maximum high idle.

It is not necessary to use a potentiometer. The 0 to 5 V signalmay be provided by a PLC or by a load share control.

37 4 to 20 mA desired speed (+ input)

27 4 to 20 mA desired speed (− input)

The 4 to 20 mA is an optional method for providing thedesired speed input.

If the 4 to 20 mA method is used to control the desired speed,the 0 to 5 V input for the speed must be disabled.

Provide an input of 4 mA for minimum high idle. Provide aninput of 20 mA for maximum high idle.

The 4 to 20 mA is an isolated input. The positive “+” inputmust be in the same circuit as the negative “-” input.

13

Optional ConnectionsTable 3

40-Pin Connector J6Optional Connections


1 Fused 24 VDC

11 -Battery

This connection provides a fused 24 VDCpower supply for the customer. The electricalpower is provided to terminal 1 via the junctionbox. The electrical power is always availablewhen the 10 amp circuit breaker in the junctionbox is switched ON.

This connection can provide a maximum of 10amperes.

39 Auto If this input is not wired correctly, the masterECM will activate a diagnostic code.

The transitions for the input must occur within1/10 second.

This input must return through terminal J6-36.

When terminal 39 is grounded to terminalJ6-36, the master ECM is ready to start theengine.

For a remote start input, the customer mustprovide an additional switch between terminalJ6-36 and terminal 29 (Start/Run).

When this method is used, the normalsequence for start-up is initiated. When theremote start switch is opened, a normalshutdown is initiated. If the cooldown isprogrammed, the engine operates for thecooldown period prior to shutdown.

24 Fuel control relay’s return If the engine harness connector for the GSOVis not used, this terminal is an option for acustomer supplied harness to the solenoid forthe GSOV.

The customer may connect a harness betweenthis terminal and terminal J6-21. For details,refer to “Wiring for the Gas Shutoff Valve(GSOV)”.

28 On/Off grid If the generator will be connected to a grid, thisinput must be used.

This input changes the generator’s “GridStatus” parameter to “ON” or to “OFF”.

When this terminal is not grounded to terminalJ6-36, the “Grid Status” is “OFF”. The engine’scontrol system governs the engine accordingto the “Governor Gain” parameters.

When this terminal is grounded to terminalJ6-36, the “Grid Status” is “ON”. The engine’scontrol system governs the engine accordingto the “Auxiliary Governor Gain” parameters.

(continued)

14

(Table 3, contd)



23 Engine failure The engine’s control system will activate thisoutput when the control system causes theengine to be shut down.

When this output is activated, this output isconnected to ground.

This output is capable of sinking 0.3 amperes.

32 Crank terminate The engine’s control system activates thisoutput when the engine’s rpm increases to thecrank terminate speed. The crank terminatespeed can be programmed with Cat ET.

This output remains activated until the engine’srpm is reduced to zero.



8 Desired timing This input is provided in order to control thebase timing of the engine.

When this input is an open circuit, the enginecontrol will use the “First Desired Timing”.

When this input is grounded to terminal J6-36,the engine control will use the “Second DesiredTiming”.

Refer to Systems Operation/Testing andAdjusting for additional information on the“Desired Timing” parameters.

33 Active alarm This output is activated if the engine’s controlsystem detects an alarm condition.

During an alarm condition, this output isconnected to ground.


22 Run relay This output is activated when the enginebegins to crank. The output remains activeuntil the beginning of engine shutdown.


This output is capable of sinking 0.3 amperes.(continued)

15

(Table 3, contd)



7 Cat Data Link +

17 Cat Data Link −

These connections provide the means forcommunicating the status of the engine controlsystem, of various engine components, andof sensors.

The Cat Data Link can be connected to theCustomer Communication Module (CCM). Forinformation on connecting the CCM, refer tothe most recent literature for the CCM.

When the Caterpillar Software for the CCM isloaded on a personal computer, the programuses this data link in order to obtain engineinformation via the CCM.

12 Emergency stop indicator

2 Emergency stop indicator

These terminals are provided for the customerto use as an indicator of an emergency stop.This circuit is normally open.

When the engine mounted emergency stopbutton is pressed, this circuit closes.

This circuit does not affect engine operation.For details, refer to “Wiring for the EmergencyStop Circuit”.

18 Manual prelube At the time of this publication, this output isnot used.

Unused TerminalsTable 4

40-Pin Connector J6Unused Terminals

6

16

26

34

38

16

Wiring for the Emergency Stop Circuit

The emergency stop buttons must be properly wiredin order to immediately stop the engine in case of anemergency situation. An emergency stop button isprovided on the engine.


Rear view of a 20 cylinder engineThe 16 cylinder engine does not have a J3/P3 connector.(1) J6 connector(2) J1/P1 connectors(3) J3/P3 connectors on engines with 20 cylinders(4) J9 connector(5) Engine mounted emergency stop button

The circuit for the emergency stop is normally closed.If the emergency stop button is pressed, the circuitis opened. Electrical power to the ignition system isimmediately removed by the engine’s control system.If the engine’s control system is controlling the GSOV,the ECM immediately removes the voltage from theGSOV. The flow of fuel is stopped.

NOTICEEmergency shutoff controls are for EMERGENCYuse ONLY. DO NOT use emergency shutoff devicesor controls for normal stopping procedure.

In addition to the normally closed electrical circuitfor emergency stopping, the emergency stop buttonis mechanically connected to another circuit that isnormally open. When the emergency stop button ispressed, the other circuit is closed. This other circuitdoes not affect engine operation. This other circuitis available to the customer via terminals J6-2 andJ6-12. These terminals are provided for the customerto use as an indicator of an emergency stop.

Illustration 8 is a wiring diagram of the enginemounted emergency stop button’s circuit.

If the customer does not supply an additionalemergency stop button, a jumper wire must beinstalled between terminals J6-10 and J6-20.

17

g01060931Illustration 8Schematic of the engine mounted emergency stop button’s circuitThe configuration for a 20 cylinder engine is shown. The 16 cylinder engine does not have a slave ECM.

The customer may supply an additional emergencystop button. The contacts of the emergency stopbutton must be normally closed. If the customersupplies more than one emergency stop button, thebuttons must be wired in series in order to operateproperly.

Illustration 9 is a wiring diagram of the enginemounted emergency stop button and an additionalcustomer supplied emergency stop button.

g01064395Illustration 9Schematic of the engine mounted emergency stop button’s circuit and a customer supplied emergency stop button

The configuration for a 20 cylinder engine is shown. The 16 cylinder engine does not have a slave ECM.

18

Wiring for the Gas Shutoff Valve (GSOV)

The GSOV must be energize-to-run. The GSOV maybe supplied by the customer or by Caterpillar. TheGSOV may be controlled by the engine’s controlsystem or by the customer’s equipment. The GSOVis also called the fuel control relay.

The ECM can supply a maximum continuous currentof 1.5 amperes to the GSOV. A relay must beinstalled if the GSOV requires a continuous currentthat is greater than 1.5 amperes.

When the engine’s control system controls the GSOV,the ECM supplies voltage to the GSOV. The valveopens in order to allow fuel to flow to the engine.When voltage is removed from the GSOV, the valvecloses and the fuel flow stops.

When the customer’s equipment provides voltageto the solenoid for the GSOV, the equipment mustinclude the necessary logic in order to ensure thatthe GSOV opens and the GSOV closes at theappropriate times.

Usually, the GSOV is installed when the piping forthe fuel is installed at the site. The components in thecircuit for the GSOV are identified in Illustration 10.

g01060579Illustration 10Left side view of a 20 cylinder engineThe 16 cylinder engine is similar.

(1) J1/P1 connectors(2) J7 connector(3) J6 connector

(4) Engine harness connector for the fuelcontrol relay

19

There are three options for wiring the GSOV. Theoptions are described in the following paragraphs.

The GSOV is controlled by the customer’sequipment. In this case, the circuit for the engine’scontrol system must be closed. Otherwise, an opencircuit diagnostic code will be activated and theengine will not start. Refer to Illustration 11 for anexample of this type of installation.

g01063416Illustration 11The GSOV is controlled by the customer’s equipment.The circuit for the engine’s control system is closed.

The GSOV is controlled by the engine’s controlsystem. The engine harness is used for theconnection. The customer may supply an additionalswitch in the electrical circuit for the GSOV. If thecustomer does not provide an optional switch, the J6connections must be closed. Refer to Illustration 12for an example of this type of installation.

20

g01063421Illustration 12The GSOV is controlled by the engine’s control system.

The GSOV is controlled by the engine’s controlsystem. The GSOV is connected to a harness thatis provided by the customer. The customer maysupply an additional switch in the electrical circuit forthe GSOV. Refer to Illustration 13 for an example ofthis type of installation.

g01063423Illustration 13The GSOV is controlled by the engine’s control system.

The GSOV is connected via a harness that is provided by the customer.

21

Wiring for Monitoring the Generator’sOutput Power

The ECM monitors the generator’s output power inorder to accurately control the air/fuel ratio. The ECMuses an output from one of the following sources inorder to monitor the generator’s output power:

• Electronic Modular Control Panel II+ (EMCP II+)

• Programmable Logic Controller (PLC)

• Wattmeter

The PLC and the wattmeter are also called powersensors.

If the generator is equipped with the EMCP II+,information on the engine load is provided via theCAT data link. The wiring is installed at the factory.No additional connections are needed.

If the generator is not equipped with the EMCP II+,information on the engine load must be provided by apower sensor.

The power sensor’s output to the ECM must be ananalog signal with a range of 0 to 4.8 VDC. Thepower sensor’s output must have a linear relationshipwith the generator’s output power. The accuracy ofthe wattmeter’s output must be within one percent ofthe generator’s actual output power.

The engine’s control system includes parameters thatallow the ECM to accurately estimate the generator’soutput power. The values for these parameters aremodified by using Cat ET. To identify the parametersfor the wattmeter, Cat ET labels the parameters“Generator Output Power Sensor”.

For details on these parameters, refer to SystemsOperation, Testing and Adjusting, RENR5978,“Electronic Control System Parameters”.

Illustration 14 is a wiring diagram for a typical powersensor.

g01064159Illustration 14Schematic of the power sensor’s input

For the actual wiring, refer to the generator’s schematic diagram.The potentiometer is optional. For further information, refer toTroubleshooting, “Ganerator Output Power Sensor - Calibrate”.

22

Inputs for the Modes of Operation

The engine’s control system has three active modesof operation: Start/Run, Auto, and Stop. The modeof operation is determined by three inputs on the J6connector. A mode is activated when the terminal forthe mode is connected to the digital return.

Table 5 lists the valid combinations of the inputswhich are determined by the positions of the engine’scontrol.

Configurations that are not shown in Table 5will activate a diagnostic code. The transitionbetween inputs must occur within 1/10 second. Ifthe transitions do not occur within 1/10 second, adiagnostic code will be activated.

Illustration 15 is a schematic of the modes’ inputsand of the switched +Battery supply to the engine’scontrol system.

Table 5

Valid Configurations of Terminals for the Engine’s Mode of Operation

InputMode

Terminal 29 Terminal 19 Terminal 39

Off/Reset No (1) No No

Yes (2) No NoStart/Run

Yes No Yes

Auto No No Yes

Stop No Yes No(1) The “No” indicates that the terminal is not connected to terminal 36.(2) The “Yes” indicates that the terminal is connected to terminal 36.

g01060955Illustration 15Schematic of the inputs and of the switched +Battery supply to the engine’s control systemThe configuration for a 20 cylinder engine is shown. The 16 cylinder engine does not have the slave ECM.

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Off/Reset – When none of the inputs are connected,the engine is in the Off/Reset mode. The switched+Battery supply to the engine’s control system is off.Any active diagnostic codes are cleared.

Start/Run – The engine start sequence will beginwhen terminal J6-29 is connected to terminalJ6-36. Switched +Battery power is supplied to theengine’s control system. The engine will run untilterminal J6-29 is disconnected from terminal J6-36.When terminal J6-29 is disconnected, the normalshutdown sequence is initiated. If the cooldownfeature is programmed, the engine will operate forthe cooldown period prior to shutdown.

Auto –When terminal J6-39 is connected to terminalJ6-36, the engine’s control system is in the AUTOmode. Switched +Battery power is supplied to theECM. The engine will not start unless terminal J6-29is also connected to terminal J6-36. This can beaccomplished with a customer supplied remote startswitch.

When terminals J6-29 and J6-39 are connectedto terminal J6-36, the engine start sequence willbe initiated. The engine will run until terminalJ6-29 is disconnected from terminal J6-36. Whenterminal J6-29 is disconnected, the normal shutdownsequence is initiated. If the cooldown feature isprogrammed, the engine will operate for the cooldownperiod prior to shutdown. The engine’s control systemwill remain in the Auto mode.

In the Auto mode, terminal J6-29 is used to controlboth the engine start sequence and the shutdownsequence.

Stop – If the engine is running, the shutdownsequence will begin when terminal J6-29 or terminalJ6-39 is disconnected from terminal J6-36 andterminal J6-19 is connected to terminal J6-36. If thecooldown feature is programmed, the engine willoperate for the cooldown period prior to shutdown.In this mode, the switched +Battery power is stillsupplied to the ECM.

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Initial Start-Up ProcedureEnsure that all of these factors are in proper conditionprior to the initial start-up: engine installation, drivenequipment, all of the related hardware, and electricalconnections. Failure to perform the commissioningprocedure could result in unsatisfactory operation.

Perform the following procedure for the initial start-upand for start-up after major maintenance and/orrepair.

1. Verify that the connections between the engine’scontrol system and the customer’s equipment areconnected properly.

2. If the information on the generator’s output poweris provided by a power sensor, check the powersensor’s offset voltage. Refer to Troubleshooting,“Generator Output Power Readings Do NotMatch”. Continue with this procedure after youhave minimized the power sensor’s offset voltage.

3. Connect Cat ET to the service tool connector.Refer to “Connecting Cat ET with the 171-4401Communication Adapter II”.

4. Set the engine control to the STOP mode. Testeach emergency stop button before the engine isstarted in order to verify that the engine’s controlsystem generates a E264 event code.

After the operation of each emergency stophas been verified, set the engine control to theOff/Reset mode.

Note: Check the generator’s protective devicesprior to start-up. Some of the generator’s protectivedevices can only be checked during engine operation.

5. Check the generator’s protective devices forproper operation.

6. Turn on the jacket water heater. Verify that theheat is set to 45 to 65 °C (113 to 150 °F).

Note: The engine may be difficult to start if the jacketwater coolant temperature is below 43 °C (110 °F).

Note: The spark plugs may become fouled withmoisture condensation if the engine is cranked andthe jacket water coolant temperature is below 43 °C(110 °F).

7. Inspect the inlet air system. Make sure that thesystem does not leak. Make sure that the systemis free of debris.

8. Inspect the fuel supply system. Make sure thatthe system does not leak. Make sure that thesystem is free of debris. Blow any debris from thefuel lines.

9. Connect a properly calibrated emissions analyzerto the exhaust stack.

10.Perform the daily inspection and all of the dailymaintenance procedures that are scheduled inOperation and Maintenance Manual, SEBU7681,“Maintenance Interval Schedule”.

11.Set the engine control to the STOP mode. Usethe “Monitoring System” screen from the “Service”drop-down menu on Cat ET to view the defaultsettings of the trip points for the alarms. Adjustthe settings, if necessary.

For the necessary values of the operatingparameters, refer to the applicable Data Sheeton engine performance in the engine’s TechnicalMarketing Information (TMI).

12.Use the “Configuration” screen from the“Service” drop-down menu on Cat ET to view theconfiguration parameters.

Note: Use the data from the gas analysis and fromCaterpillar Software, LEKQ6378, “Methane NumberProgram” in order to determine the correct settingsfor the “Fuel Quality” and the “Gas Specific Gravity”parameters.

a. View the parameters that are listed in Table 6.Program the parameters, if necessary.

Incorrect programming of the parameters maylead to complaints about performance and/or toengine damage. For details, refer to SystemsOperation, Testing and Adjusting, RENR5978,“Electronic Control System Parameters”.

Note: If the generator set is equipped with anEMCP II+ system, it is not necessary to program the“Generator Output Power Sensor Scale Factor” andthe “Generator Output Power Sensor Offset”.

Table 6

Configuration Parameters for G3500C Engines

Timing Control

“First Desired Timing”

“Second Desired Timing”

Air/Fuel Ratio Control

“Fuel Quality”

“Gas Specific Gravity”

“Fuel Specific Heat Ratio”

“Desired Emission Gain Adjustment”

“Air/Fuel Proportional Gain”

“Air/Fuel Integral Gain”

Speed Control(continued)

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(Table 6, contd)

Configuration Parameters for G3500C Engines

“Low Idle Speed”

“Minimum High Idle Speed”

“Maximum High Idle Speed”

“Engine Accel. Rate”

“Desired Speed Input Configuration”

“Governor Type Setting”

“Engine Speed Droop”

“Governor Proportional Gain”

“Governor Integral Gain”

“Governor Derivative Gain”

“Auxiliary Proportional Governor Gain 1”

“Auxiliary Integral Governor Gain 1”

“Auxiliary Derivative Governor Gain 1”

Start/Stop Control

“Driven Equipment Delay Time”

“Crank Terminate Speed”

“Engine Purge Cycle Time”

“Engine Cooldown Duration”

“Cycle Crank Time”

“Engine Overcrank Time”

“Engine Speed Drop Time”

“Engine Pre-lube Time Out Period”

Monitoring and Protection

“High Inlet Air Temp Load Set Point”

Power Monitoring

“Generator Output Power Sensor Scale Factor”

“Generator Output Power Sensor Offset”

“Engine Output Power Configuration”

“Engine Driven Accessory Load Configuration”

Information for the ECM

“Engine Serial Number”

“Equipment ID”

“Customer Password #1”

“Customer Password #2”

“Total Tattletale”

13. Turn ON the fuel supply to the engine. Verify thatno gas is leaking. Verify that the gas does not flowpast the GSOV.

Unburned gas in the inlet manifold and/or in theexhaust manifold can ignite when the engine isstarted. Personal injury and/or property damagecan result. Use this procedure to clear the engineand the exhaust system of unburned gas:

Before starting an engine that was stopped by ter-minating the ignition system, turn the gas supplyOFF. Crank the engine for approximately 15 sec-onds in order to clear any unburned gas from theengine and the exhaust system.

14.Start the engine.

The engine will accelerate to low idle rpm.Operate the engine at low idle. Verify the followingconditions:

• Proper engine oil pressure

• No fluid leaks

• No gas leaks

Several attempts may be required for the initialstart-up before air is purged from the fuel lines.

Note: If the engine will not start, use Cat ET to checkfor diagnostic codes and for event codes. Correctany active conditions before you attempt to start theengine again.

15.After the engine is running, test the operation ofeach emergency stop button.

After each test, reset the emergency stop buttonand set the engine control to the Off/Reset mode.Then restart the engine. After all of the emergencybuttons have been tested, use Cat ET to clear theevent codes from the ECM.

Note: Some of the generator’s protective devices canbe checked prior to start-up. Some of the generator’sprotective devices can only be checked during engineoperation.

16.Check the generator’s protective devices forproper operation.

17. Increase the engine speed to high idle rpm. Verifythat the engine is stable.

If the engine is unstable, perform the followingprocedure.

a. Record the values for these parameters:

• “Governor Proportional Gain”

• “Governor Integral Gain”

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• “Governor Derivative Gain”

b. Set the values for the “Governor ProportionalGain”, “Governor Integral Gain”, and “GovernorDerivative Gain” parameters to zero.

c. Adjust the “Fuel Quality” parameter until theengine becomes stable and the exhaustoxygen is approximately four percent. Verifythat the exhaust port temperatures are belowthe setpoint for a warning.

d. Adjust the primary governor. Refer to “Adjustingthe Governor”.

18.Select the “Information” drop-down menu in orderto view the status parameters. Review the valuesof the status groups on Cat ET. Verify that thepumps for the cooling system are operating. Verifythat the cooling system temperatures and thecooling system pressures are within the correctoperating ranges.

19.Close the main circuit breaker for the generator inorder to engage the generator.

Note: When the engine load exceeds 25 percent,the air/fuel ratio control will operate in the feedbackmode.

20.Slowly ramp the load up to 30 percent.

Note: When the air/fuel ratio control is in thefeedback mode, the Fuel Correction Factor (FCF)may no longer be 100 percent. The ECM may adjustthe FCF in order to compensate for the fuel qualityand for the ambient conditions.

21.Set the “Desired Emission Gain Adjustment” to avalue of “100”.

22.Verify that the value of the “Generator Real kW”parameter in Status Group 1 is within 1 percent ofthe generator’s output power.

If the reading on Cat ET is not within onepercent of the generator’s output power, referto Troubleshooting, “Generator Output PowerReadings Do Not Match”.

When the value of the “Generator Real kW”parameter is within 1 percent of the generator’soutput power, continue with this procedure.

23.Slowly ramp up to 50 percent load. Allow thejacket water coolant temperature to reach 75 °C(167 °F).

24.Slowly ramp up to 70 percent load. Verify that theengine is stable.

If the engine is unstable, adjust the auxiliarygovernor. Refer to “Adjusting the Governor”.

25.Verify that the NOx emissions are above thedesired full load setting.

26.Slowly ramp up to 100 percent load. Verify thatthe engine is stable.

If the engine is unstable, adjust the auxiliarygovernor. Refer to “Adjusting the Governor”.

27.Verify that the value of the “Generator Real kW”parameter is within 1 percent of the generator’soutput power.

28.Adjust the “Desired Emission Gain Adjustment”parameter in order to obtain the values ofemissions that are required at the site.

• To lean the air/fuel mixture, decrease the gainadjustment.

• To richen the air/fuel mixture, increase the gainadjustment.

A small change in the “Desired Emission GainAdjustment” causes a large change in the actualexhaust emissions. For example, an adjustment ofone percent in the parameter’s value will result in achange of 20 to 40 ppm in the actual level of NOx.

When you adjust the exhaust emissions, make asmall change in the value of the gain. Wait untilthe system stabilizes. Check the emissions again.Repeat the process until the desired emissionslevel is achieved.

Use the emissions analyzer in order to verify thatthe values of emissions meet the requirementsof the site.

29.Record the data from all of the status groups onCat ET. Save the data for future reference.

Adjusting the GovernorThe response of the throttle actuator can be adjustedwith the Caterpillar Electronic Technician (Cat ET).Use Cat ET to change these three parameters:

• Proportional gain

• Integral gain

• Derivative gain

The default values should be sufficient for initialstart-up. However, the values may not provideoptimum performance.

These adjustments are provided in order to obtainoptimum responses to changes in the load and in thespeed. The adjustments also provide stability duringsteady state operation.

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If you have a problem with instability, alwaysinvestigate other causes before you adjust thegovernor. For example, diagnostic codes andunstable gas pressure can cause instability.

When you adjust the primary governor, make surethat the “Grid Status” parameter is “Off”. When youadjust the auxiliary governor, make sure that the“Grid Status” parameter is “On”.

To change the proportional gain, the integral gain, orthe derivative gain, use the “Real Time Graphing”feature on the “Information” drop-down menu ofCat ET. The graph provides the best method forobserving the effects of your adjustments.

After you make adjustments, always test the stabilityby interrupting the engine speed and/or load. Operatethe engine through the entire range of speeds and ofloads in order to ensure stability.

Note: Adjustment of the proportional gain directlyaffects the speed of the throttle actuator when thereis a difference between the actual engine speed andthe desired engine speed. An excessive increase ofthe proportional gain may amplify instability.

To set the proportional gain, increase the proportionalgain until the actuator becomes unstable. Slowlyreduce the proportional gain in order to stabilize theactuator. Observe that the engine operates properlywith little overshoot or undershoot.

The adjustment of integral gain dampens theactuator’s response to changes in load and in speed.Increasing the integral gain provides less damping.Decreasing the integral gain provides more damping.To reduce overshoot, decrease the integral gain. Toreduce undershoot, increase the integral gain.

Note: An increase of the integral gain may require adecrease of the proportional gain in order to maintaina stable operation.

Illustration 16 shows some typical curves for transientresponses.

g01017530Illustration 16Typical response curves

(Y) Engine speed(X) Time(1) The proportional gain is too high and the integral gain is too

low. There is a large overshoot on start-up and there aresecondary overshoots on transient loads.

(2) The proportional gain is slightly high and the integral gain isslightly low. There is a slight overshoot on start-up but theresponse to transient loads is optimum.

(3) The proportional gain is slightly low and the integral gain isslightly high. There is optimum performance on start-up butslow response for transient loads.

(4) The proportional gain is too low and the integral gain is toohigh. The response for transient loads is too slow.

(5) The response to transient loads is adjusted for optimumperformance.

Decrease the derivative gain until a slow, periodicinstability is observed. Then, slightly increase thederivative gain. Repeat the adjustments of theproportional gain and of the integral gain. Continueto increase the derivative gain and readjust theproportional gain and the integral gain until stabilityis achieved and the engine’s response to changes inload and in speed is optimized.

Illustration 17 is a graphic representation of adjustingthe derivative gain.

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g01017541Illustration 17The increased width of the line for the actuator voltage indicatesthat the throttle actuator is more active as the derivative gainincreases.

(Y) Actuator voltage(X) Time in seconds

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REHS1438 INSTALLATION G3520C