Customer Interface for Certain G3600 A4 Engines {1901, 4490, 7451} Caterpillar

Engine

G3606 (S/N: JFE1-UP)

G3608 (S/N: XH71-UP)

G3612 (S/N: BB21-UP)

G3616 (S/N: ZZY1-UP)

Introduction

This Special Instruction provides information on customer interface for G3600 A4 Engines.

Note: Do not perform any procedure in this publication or order any parts until you understand the information that is contained in this publication.

Control System Overview

The G3600 A4 control system consists of the A4 Electronic Control Module (ECM), connected to an array of sensors and control devices used by the ECM to monitor, control, and protect the engine. A "local" Controller Area Network (CAN) data link is used on the engine to allow the ECM to communication with various intelligent control and I/O devices. There is also an array of sensors and control devices that are hardwired to the ECM to complete the system. The spark plugs are driven by the ECM, via ignition transformers at each cylinder.

A Global CAN data link is used to connect the ECM to other devices including the Caterpillar^® telematics system Product Link, and optional Cat control panels, and the Cat^® Electronic Technician (ET) service tool. A global data link is also available for connection to a customer CAN network.

Refer to the Operation and Maintenance Manual and individual engine Schematic for individual electrical system component locations on the engines.

Illustration 1	g03849563
Block diagram of the G3600 A4 control system

Power Supply Requirements

The G3600 A4 control system uses customer provided 24 VDC for control power. The customer is required to provide 24 VDC +/- 2 VDC to the engine terminals under all operating conditions. Current (amperage) requirements for the engine and optional control panels are shown below.

General Power Requirements

Power Supply current capability:

• 20A Minimum, maximum ripple voltage of 150 mV

The steady state amperage draws of an operating engine and control panels are approximately:

• G3600 A4 with Product Link – 5.8A – Engine Running

• G3600 A4 with Product Link – 3.5A – Engine not running, key switch input on

• Optional Operator Control Panel (OCP) – 0.9A

• Optional Color Human Machine Interface (HMI) Panel – 0.9A

Control Panels

There are two control panels available for the G3600 A4. The OCP provides for an operator interface and control with a 5.5 inch monochrome display for engine monitoring. The HMI is a 15 inch color display that provides an intuitive graphic interface for engine control and monitoring.

Operator Control Panel

The main component of the Operator Control Panel (OCP) is the electronic OCP Module. Some of the functions include within the OCP are:

• Sending start and stop signals to the engine

• Providing visual indications when warning or shutdown events occur

• Displaying engine information

• Displaying Suspect Parameter Number (SPN) and Failure Mode Identifier (FMI) information for events

• Programming set points for the standard OCP

Refer to System Operation and Troubleshooting, Testing and Adjusting, UENR3193 for a complete description of OCP functions and operation.

Illustration 2	g03849575
OCP

Illustration 3	g03849577
Enclosed OCP

The traditional configuration includes all the components mounted within an enclosure and is designed to meet NEMA 4 requirements.

Illustration 4	g03849578
Plate-mounted OCP

This style requires mounting within a customer provided enclosure to complete the installation. The plate-mounted OCP can be used to save space by installing the OCP within the main compressor control enclosure.

OCP Customer Electrical Connections

Grounding

Illustration 5	g03849593

Proper grounding is necessary for optimum engine performance and reliability. Improper grounding can result in uncontrolled or unreliable electrical circuit paths that can damage the bearing surfaces and aluminum components. These uncontrolled electrical paths can also degrade the engine electronics and communications. All grounding connections must be robust to ensure proper function. Check to see that all grounds are secure and free of corrosion.

All grounding connections must be tied to a robust earth ground, which is typically a metal stake dedicated to the purpose of providing an electrical path to the earth. Each individual electrical system should be tied to the ground stake with its own cable, and all connections on these ground paths must be protected from corrosion to ensure minimal resistance along the path.

The primary ground for the engine electrical system is the connection to the battery negative terminal. Attachments such as the charging alternator must be grounded to the battery negative terminal with a cable capable of carrying the full charging current of the alternator.

The engine block must be grounded, but by a separate path other than path of the engine electrical components. Do not ground the battery negative terminal to the engine block. The grounding connection on the block can be any of the unused bolt holes on the end housings. The housings are bolted to the block in multiple locations ensuring a robust conductive path between the block and housings. Choose the connection location to provide an electrically robust connection to the ground strap, and to ensure the shortest practical path to the earth ground.

Connect the battery negative terminal to the earth ground with a minimum #6 AWG cable or braided strap. Ground the engine block to the earth ground with a separate ground strap. Grounding straps are to be furnished by the customer.

If rubber couplings are used to connect the engine cooling system to the external piping and radiator, those external systems can become electrically isolated from the engine. Because there is no electrical path between them, a potential difference can exist. Electrically couple the two piping systems (on-engine and external) by using grounding cables across the rubber couplings to eliminate any potential difference.

Control Wiring

Illustration 6	g03849597

All electrical control connections to the engine are made at the ECM enclosure, on the right side of the engine near the flywheel.

Power Supply Connection

Illustration 7	g03849598
(1) T2 B- (2) T6 B+

The customer provided +24 VDC power supply is terminated in the ECM enclosure. The +24 VDC is connected to terminal T6 B+, the -24 VDC is connected to terminal T2 B-. A 25.4 mm (1 inch) knock-out is provided on the bottom of the enclosure, immediately below the power terminals for the field connection. A length of flexible conduit is required for the connection to the terminal box.

The power terminals are designed to accommodate #10 AWG wire through #6 AWG wire.

Customer Interconnect - A4

Engine to OCP

Illustration 8	g03849627
Schematic for power connection (3) 70-pin engine interface connector (4) Engine interconnect harness

The engine is connected to the customer-mounted OCP panel by a factory provided engine interconnect harness. The harness includes a 70-pin connector that is connected to the engine ECM enclosure engine interface connector (EIC).

Illustration 9	g03849629
(3) 70-pin engine interface connector (EIC)

Illustration 10	g03849631
(5) Spare wires (6) Terminal block #2 (TB2) (7) Customer connection (8) Ethernet (9) Terminal block #1 (TB1)

The engine interconnect harness is routed in the field from the EIC to the OCP and terminated on OCP Terminal Block #1 (9), on the left side of the OCP back backplane. Some customer I/O will also terminate on TB1.

Terminal Block #2 (6) is on the right side of the OCP panel and is used for more customer connections.

Customer Connections - I/O

Remote Start/Stop

Illustration 11	g03851961

Illustration 12	g03729847
Cat ET of an OCP Configuration for hard wired remote start/stop

Illustration 13	g03854461
Cat ET of an engine ECM Configuration for hard wired start from OCP.

Wiring remote start/stop signals to the OCP requires two contacts. The example below utilizes OCP digital inputs #3 and #4.

• Stop Signal - Normally closed, open for start/run between OCP terminal TB2-82 and Digital Reference.

• Start Signal - Normally open, closed for start/run between OCP terminal TB2-93 and Digital Reference.

• A single form "C" relay contact can be used to accomplish the remote start/stop function.

When BOTH start/stop contacts change state from their normal position a start sequence is initiated. When the contacts return to their normal position the engine will go through a normal stop and post lube sequence, including a cool down period if the cool down timer is programmed for greater than zero. If a cool down period is desired, the engine should be unloaded as much as possible during the cool down period.

Failure to operate the two start/stop inputs simultaneously will result in the following code:

• 1656-2 Engine Automatic Start Enable Switch : Erratic, Intermittent, or Incorrect

Remote Emergency Stop

Illustration 14	g03849717

A remote Emergency Stop (E-Stop) push button can be utilized by wiring a two pole switch in Illustration 14. Both poles of the switch are normally closed for start/run, open when pressed for E-Stop.

The remote E-Stop push button connects the two sides of OCP terminal TB1-22 to one another and the two sides of OCP terminal TB1-23 to one another when the E-Stop is in the normal, not pressed state. The orange switch in the center of TB1-22 and TB1-23 must be opened to enable the remote E-Stop. Opening BOTH sets of remote E-Stop contacts results in an immediate engine E-Stop sequence. Multiple remote E-Stop push buttons can be placed in series.

If one of the contacts on the E-Stop switch is opened while the other remains closed, or one of the wires in the circuit is disconnected a 3607-2 Engine Emergency Shutdown Indication : Erratic, Intermittent, or Incorrect fault code will occur, but an emergency stop will not take place.

An E-Stop causes the ECM to deenergize the Gas Shut Off Valve (GSOV) and turns off the engine ignition. Post lubrication of the engine is not completed after an E-Stop. The E-Stop should not be used for a normal shutdown of the engine.

Illustration 15	g03851970

Illustration 16	g03854482
Alternate emergency stop wiring

As an alternative, a single contact remote E-Stop circuit can be used by installing jumpers between terminals TB1-22 and TB1-23 and connecting a single set of wires to the remote contact as shown in Illustration 16. Two independent contacts are recommended to retain the benefit of the broken wire detection.

Illustration 17	g03849809
OCP setting

The OCP E-Stop function must be configured as shown in Illustration 17.

Driven Equipment Ready (User-Defined Shutdown)

This input is used by the customer to communicate that the driven equipment (compressor and associated ancillary devices) is ready for starting and running. This input is a contact connected between OCP terminal TB1-61 (Digital reference) and TB1-51. The contact is closed to allow the engine to start and run. When the contact is open, the engine will not crank. The ECM generates an event code if this input does not close in the programmed delay time once a start sequence is initiated.

When the engine is running, this input should remain closed unless a fault or other condition on the connected equipment requires an immediate shutdown of the engine. This function is managed by the customer control system. When the input opens while the engine is running the ECM generates a fault code, 970-0 Engine Auxiliary Engine Shutdown Switch : High - most severe (3), and de-energizes the GSOV. Because the cooldown is not performed and a latched event code is generated, using this input for normal shutdown of the engine is not recommended. Postlube will still operate as normal.

The input should always be open when a shutdown of the engine is needed due to a condition on the driven equipment or the site. It is recommended that when possible the driven equipment input remains closed during an operator or engine initiated shutdown. Opening the driven equipment ready contact during a normal engine shutdown can lead to confusion as to the initial cause of the shutdown because of the fault code generated by the driven equipment ready input.

Illustration 18	g06047848
(10) Factory installed jumper wire (remove)

The factory installed jumper wire 229-CX39 (10) between OCP terminal TB1- 61 and TB1-51 must be removed when the driven equipment input is used.

Illustration 19	g03849736
ECM setting

The setting in Illustration 19 is the maximum amount of time allowed for the driven equipment input to close once a start command is given to the engine. If the driven equipment input does not close within this time delay, a 970-0 Engine Auxiliary Engine Shutdown Switch : High - most severe (3) fault code is generated.

This setting is also the time delay that the input must be opened before a running engine shuts down. A setting of zero is recommended.

Remote Idle/Rated Switch

Illustration 20	g03849819

The idle rated switch is connected between OCP TB1-58 and digital return (OCP Terminal TB1-18). When this input is connected to digital return, the engine will run at the idle speed that has been programmed in the ECM. When this terminal is NOT connected to digital return, the engine will run at the desired speed as requested by the control inputs.

Keyswitch (power save mode)

Illustration 21	g03854606

Illustration 22	g03849743
OCP configuration

The key switch input is used to place the ECM into a power-saving mode.

The OCP provides an output to the ECM through the engine interconnect harness on OCP terminal TB1-70. When configured as shown in Illustration 22, this output will deenergize the keyswitch signal after the Power Mode Delay Timer and the engine will enter a low-power consumption state. The Power Mode Delay Timer starts after the engine shuts down for any reason. Pressing any key on the OCP keypad will cause the output to reenergize, and the ECM will return to normal operation.

There are no external connections to the OCP for this circuit, however the settings shown in Illustration 22 are recommended to help conserve 24 VDC power battery power.

Digital Output #3 should ALWAYS be configured as shown in Illustration 22, to provide the key switch input to the ECM, even if the power-saving feature is not used.

Illustration 23	g03849746
OCP setting

The power save feature is activated as shown in Illustration 23. The time delay can be set as desired for the specific installation.

Setting the Electronic Control Module Reduced Power Mode Enable Status to "Disable" will prevent the engine from entering the power save mode.

OCP/ECM Reset

Illustration 24	g03859756

The OCP and ECM can be reset by briefly removing power from the OCP. The reset will clear any latched fault in the ECM and allow for restarting of the engine. A normally closed contact is placed in series with the wire number 150 on OCP TB1-48. Opening the contact will remove power from the OCP, and turn off the keyswitch input to the engine, which will cause the engine ECM to power down. Closing the contact restarts the OCP, followed by the ECM as the key switch output from the OCP returns to its normal state. Refer to Illustration 24.

Illustration 25	g06093974

Illustration 26	g06094002

The OCP and ECM can also be reset utilizing digital inputs programmed as Alarm Acknowledge and ECU Fault Reset. The example above uses OCP digital inputs #1 and #2. To reset the OCP and ECM the Alarm Acknowledge input is taken to Digital Reference. Then the ECU Fault Reset input must be taken to Digital Reference within 60 sec to the faults to be cleared. If 60 sec has elapsed, the Alarm Acknowledge input must be taken to Digital Reference again before the ECU Fault Reset will work. Refer to Illustration 25.

This process can be used to reset the engine after a fault shutdown or to reenergize the engine from the low-power mode. Care must be taken to ensure any conditions causing faults on the engine or the driven equipment are appropriately resolved before restarting the engine.

Engine Running Driver

Illustration 27	g03854659

Illustration 28	g03849899
The OCP Digital Output 2 should be disabled

This output is used as an engine running lamp driver (sinking). The output activates (low) after crank terminate and deactivates (high) when a stop or shutdown occurs.

Terminal TB1-20 in the OCP is connected to the remote indicating device such as a relay, lamp, or PLC input. The other side of the device is connected to Battery +. When the engine is running, the output switches on and current flows to energize the indicating device.

Engine Shutdown Driver

Illustration 29	g03854719

Illustration 30	g03849901
OCP Digital Output 5 is configured

This output is used as an engine shutdown lamp driver. The output activates (high) and when an engine fault shutdown has taken place. The OCP Digital Output 5 is used for this signal. Resetting the engine shutdown will cause the output to deactivate (high).

Terminal TB2-84 in the OCP is connected to the remote indicating device such as a relay, lamp, or PLC input. The other side of the device is connected to Battery -. When a shutdown exists, the output switches on and +24 VDC is applied to the indicating device.

Engine Warning Driver

Illustration 31	g03854721

Illustration 32	g03849920
OCP Digital Output 4 is configured

This output is used as an engine summary alarm lamp driver. The output activates (high) when an engine alarm or diagnostic exists. Clearing of the alarm will cause the output to deactivate (low).

Terminal TB2-106 in the OCP is connected to the remote indicating device such as a relay, lamp, or PLC input. The other side of the device is connected to Battery -. The OCP Digital Output 4 is used for this signal. When an alarm exists, the output switches on and +24 VDC is applied to the indicating device.

Desired Engine Speed Control Input

Illustration 33	g03849933
ECM setting for speed control from OCP

Note: ECM setting for use with OCP keyboard and 0-5 VDC ONLY. For 4-20 mA, Refer "4-20 mA Speed Control Input".

The OCP module keypad can be used to set the desired engine speed. Also, a remote 4-20 mA or 0-5 VDC signal for desired speed command can be used. Settings in the OCP and ECM both effect the desired speed control input.

When the engine is running and the OCP Idle/Rated speed input is open, the desired engine speed control input is used to set the engine speed.

When the OCP is used to provide the speed control input to the ECM, the OCP communicates the desired speed command to the ECM via the CAN data link. The engine ECM is configured as shown in Illustration 33.

The OCP is then configured for the type of speed control to be used.

Engine Speed Control with OCP keypad

The OCP module can be configured to control the desired engine speed from the OCP keypad. In this configuration there is no external/remote signal connected to the OCP. Keypad control is the OCPs default configuration. Programming any OCP input for "Desired Engine Speed Command" will disable keypad control of the engine speed.

This method of speed control can be used as a back-up to analog signals from a customer system and for diagnostic and troubleshooting purposes.

Engine Speed Control with OCP Analog Input

When an external voltage signal (for current use alternate wiring method) is used for speed control, Analog Input #3 on the OCP is the recommended input. The examples below indicate how to use this input. The OCP Terminals for Analog Input 3 are (+) TB2-70 and (-) TB2-79. A shield can be connected on TB2-80.

The shield can be grounded on the customer side as desired in the installation.

0-5 VDC Speed Control Input

Illustration 34	g03849937

Illustration 35	g03850103
Minimum Data Range should match the desired engine operating speed when 0V is applied to the speed control input. Maximum Data Range should match the rated or the maximum operating speed when 5V is applied to the speed control input.

For 0-5V speed control the +V signal is connected to OCP TB2-70, the -V signal is connected to OCP TB2-79.

Data Connections

The OCP provides a connection point for the Engine's Global CAN data link and a MODBUS Ethernet data link to enable data communication between the engine and external systems.

Global CAN Data Link

Illustration 36	g03850104

The Global CAN Data Link is accessed on OCP TB1-34 (Global Data Link -), TB1-42 (Global Data Link Shield), and TB1-50 (Global Data Link +).

If the wire length to the connected system exceeds 1 meter, the CAN terminating resistor (120 ohm) should be moved to the end of the new trunk line.

Ethernet Connection (Modbus TCP)

Illustration 37	g03850105

Illustration 38	g03850108
OCP Modbus TCP configuration

The Ethernet Modbus TCP data connection to the OCP is accessed on the RJ-45 connector below TB2

Ethernet addressing is established in the OCP with parameters listed in Illustration 38.

RS-485 SCADA (Modbus RTU)

Illustration 39	g03850110

Illustration 40	g03850111
OCP Modbus configuration

The Modbus RTU RS-485 data connection to the OCP module is accessed on OCP Terminals TB2-90 (Modbus -), TB2-100 (Modbus +) and TB2-101 (Modbus Ref).

The RS-485 connection is configured in the OCP with the settings in Illustration 40.

4-20 mA Engine Speed Output

Illustration 41	g03854430

Illustration 42	g03854433
The minimum and maximum data range settings are used to scale the 4-20 mA output.

A 4-20 mA actual engine speed signal from the engine can be obtained by using one of the OCP analog outputs. To use analog output #1, connect (+) 4-20 mA to OCP TB2-36 and connect (-) 4-20 mA to OCP TB2-48.

Schematic of Engine I/O with OCP

Illustration 43	g06047904
OCP terminal block #1 (TB1) customer connection

Illustration 44	g06094368
OCP terminal block #2 (TB2) customer connection

Customer Electrical Connections Without OCP

When using the Cat HMI or a third-party control panel, the recommended engine interface wiring is as shown below. The referenced signals are available from the engine interface harness or directly at the 70-pin engine interface connector on the ECM enclosure.

Remote Start/Stop

Illustration 45	g03849960

Illustration 46	g03849961
ECM configuration

A single normally open relay contact can be used to accomplish the remote start/stop function. When EIC pins 46 and 47 are connected to Digital Reference (EIC Pin 5) a start sequence is initiated. When the contact returns to its normal state the engine will go through a normal stop and post lube sequence, including a cool down period if the cool down timer is programmed for greater than zero. If a cool down period is desired, the engine should be unloaded as much as possible during the cool down period.

Remote Emergency Stop

Illustration 47	g03857246

A remote Emergency Stop (E-Stop) push button can be utilized by wiring a two pole switch as in Illustration 47. Both poles of the switch are normally closed for start/run, open when pressed for E-Stop.

The remote E-Stop push button connects EIC pins 22 and 23 to Digital Reference (EIC Pin 5). In its normal, not pressed state. Opening BOTH sets of remote E-Stop contacts results in an immediate engine E-Stop sequence. Multiple remote E-Stop push buttons can be placed in series.

If one of the contacts on the E-Stop switch is opened while the other remains closed, or one of the wires in the circuit is disconnected a 3607-2 Engine Emergency Shutdown Indication : Erratic, Intermittent, or Incorrect fault code will occur, but an emergency stop will not take place.

An E-Stop causes the ECM to deenergize the Gas Shut Off Valve (GSOV) and turns off the engine ignition. Post lubrication of the engine is not completed after an E-Stop. The E-Stop should not be used for a normal shutdown of the engine.

Illustration 48	g03857249
Alternate emergency stop wiring

As an alternative, a single contact in the remote E-Stop circuit by installing jumpers between terminals EIC pins 22 and 23 and connecting a single set of wires to the remote contact as shown in Illustration 48. Two independent contacts are recommended to retain the benefit of the broken wire detection.

There are no engine ECM or OCP configurations associated with the Emergency Stop, it is always enabled.

Driven Equipment Ready (User-Defined Shutdown)

Illustration 49	g03849981

This input is used by the customer to communicate that the driven equipment (compressor and associated ancillary devices) is ready for starting and running. This input is a contact connected between EIC pins 51 and Digital Reference (EIC Pin 5). The contact is closed to allow the engine to start and run. When the contact is open, the engine will not crank. The ECM generates an event code if this input does not close in the programmed delay time once a start sequence is initiated.

When the engine is running, this input should remain closed unless a fault or other condition on the connected equipment requires an immediate shutdown of the engine. This function is managed by the customer control system. When the input opens while the engine is running the ECM generates a fault code, 970-0 Engine Auxiliary Engine Shutdown Switch : High - most severe (3), and de-energizes the GSOV. Because the cooldown is not performed and a latched event code is generated, using this input for normal shutdown of the engine is not recommended. Postlube will still operate as normal.

The input should always be open when a shutdown of the engine is needed due to a condition on the driven equipment or the site. It is recommended that when possible the driven equipment input remains closed during an operator or engine initiated shutdown. Opening the driven equipment ready contact during a normal engine shutdown can lead to confusion as to the initial cause of the shutdown because of the fault code generated by the driven equipment ready input.

Illustration 50	g03858879
ECM setting

The setting in Illustration 50 is the maximum amount of time allowed for the driven equipment input to close once a start command is given to the engine. The delay time corresponds with the ECM for the amount of time it takes to react to the input while the engine is running to force a shutdown. If it does not close within this time delay a 970-0 Engine Auxiliary Engine Shutdown Switch : High - most severe (3) fault code is generated.

This setting is also the time delay that the input must be opened before a running engine shuts down. A setting of zero is recommended.

Remote Idle/Rated Switch

Illustration 51	g03849984

The idle rated switch is connected between EIC Pin 58 and digital return (EIC Pin 5). When this input is connected to digital return, the engine will run at the idle speed that has been programmed in the ECM. When this terminal is NOT connected to digital return, the engine will run at the desired speed as requested by the control inputs.

Keyswitch (power save mode / engine reset)

Illustration 52	g03849986

The key switch input is used to place the ECM into a power-saving mode.

The customer provides an input to the ECM through EIC pin 70. When +24 VDC is connected to the input, the ECM operates normally. When +24 VDC is removed, the engine will enter a low-power consumption state.

The key switch input can also be used to reset the engine after a latched fault by momentarily removing the 24 VDC signal then reapplying it.

Manual Prelube Input

Illustration 53	g03856991

The engine prelube pump can be activated manually by connecting EIC pin 14 to Digital Reference (EIC Pin 5). When the connection is removed, the prelube pump will turn off.

Engine Running Driver

Illustration 54	g03857195

This output is used as an engine running lamp driver (sinking). The output activates (low) after crank terminate and deactivates (high) when a stop or shutdown occurs.

EIC Pin 20 is connected to the remote indicating device such as a relay, lamp, or PLC input. The other side of the device is connected to Battery +. When the engine is running the output switches on and current flows to energize the indicating device.

There are no OCP or ECM settings associated with this output.

Engine Shutdown Driver

Illustration 55	g06047908

This output is used as an engine shutdown lamp driver (sinking). The output activates (low) when an engine fault shutdown has taken place. Resetting the engine shutdown will cause the output to deactivate (high).

EIC Pin 19 is connected to the remote indicating device such as a relay, lamp, or PLC input. The other side of the device is connected to Battery +. When a shutdown exists the output switches on and current flows to energize the indicating device.

There are no OCP or ECM settings associated with this output.

Engine Warning Driver

Illustration 56	g06047912

This output is used as an engine summary alarm lamp driver (sinking). The output activates (low) when an engine alarm or diagnostic exists. Clearing of the alarm will cause the output to deactivate (high).

EIC Pin 25 is connected to the remote indicating device such as a relay, lamp, or PLC input. The other side of the device is connected to Battery +. When an alarm exists the output switches on and current flows to energize the indicating device.

Prelube Status Driver

Illustration 57	g03857200

This output is used to indicate the status of the engine prelube pump output. The output activates (high) when the engine prelube pump is activated for pre-lubrication or post lubrication.

EIC Pin 21 is connected to the remote indicating device such as a relay, lamp, or PLC input. The signal is +24 VDC and the other side of the device must be connected to Battery -. The current draw on the output must be less than 2 A.

Engine Speed Control

When an external signal is used for speed control the ECM and wiring is as shown below.

4-20 mA Speed Control Input

Illustration 58	g03857263

Illustration 59	g03849999
Minimum engine high full speed should match the desired engine operating speed when 4 mA is applied to the speed control input. Maximum engine high full speed should match the rated or the maximum operating speed when 20 mA is applied to the speed control input.

For 4-20 mA control the (+)4-20 mA signal is connected to EIC pin 10, the (-)4-20 mA signal is connected to EIC pin 11.

0-5 VDC Speed Control Input

Illustration 60	g03857272

Illustration 61	g03850000
Minimum engine high full speed should match the desired engine operating speed when 0 VDC is applied to the speed control input. Maximum engine high full speed should match the rated or the maximum operating speed when 5 VDC is applied to the speed control input.

For 0-5 VDC speed control the (+) 5 VDC signal is connected to EIC pin 10, the (-) 5 VDC signal is connected to EIC pin 11.

Global CAN Data Link

Illustration 62	g03857275

The Global CAN Data Link is accessed on EIC pin 34 (Global Data Link -), EIC pin 42 (Global Data Link Shield), and EIC pin 50 (Global Data Link +).

If the wire length to the connected system exceeds 1 meter, the CAN terminating resistor (120 ohm) should be moved to the end of the new trunk line.

Other Engine Interfaces

Fuel Quality (LHV) Input

Fuel quality is an important user set configuration value. The fuel quality is normally a fixed constant indicating the energy content of the fuel, however the engine has the capability to use an analog input for fuel quality when needed.

The parameter defaults to a configured value set in Cat ET. Alternatively, when fuel quality is known to vary significantly a 4-20 mA input to the ECM can be configured to receive the fuel quality value from instrumentation on site. The site will require a means of measuring the actual fuel lower heating value (LHV) and provide a corresponding signal to the ECM.

Fuel Quality – Fixed Value

Illustration 63	g03850113

When using a fixed, configured value the ECM is set up as shown in Illustration 63. Most installations will use this configuration. The fuel quality is set as a constant in the ECM. The "Fuel Quality" field is set to the lower heating value of the actual engine fuel, based on a recent gas analysis.

Variable Fuel Quality

When engine fuel lower heating value changes over a wide range the LHV setting in the engine can be updated by a 4-20 mA input.

Fuel Quality – 4-20 mA Input

Illustration 64	g03857289
With OCP

Illustration 65	g03857291
Without OCP

Illustration 66	g03850114
The Fuel Quality Sensor LHV Lower Setpoint is the value of the Fuel LHV when 4 mA is applied to the input. The Fuel Quality Sensor LHV Upper Setpoint is the value of the Fuel LHV when 20 mA is applied to the input.

When using a local instrument to provide the Fuel Quality setting, a 4-20 mA signal from a customer instrument measuring fuel LHV is required. The following settings in the ECM are used, and the signal is wired as shown. The (+)4-20 mA signal is applied to OCP TB1-12 or EIC terminal 12, the (-)4-20 mA to TB1-13 or EIC terminal 13. If the OCP is not used, the connections are made to the EIC terminals 12 and 13 respectively.

Ambient Based Rating Outputs

There are two 4-20 mA analog outputs to support the application of the ambient based rating feature of the G3600 A4 engine.

Percent of Max Load (Actual Engine Percent Torque)

Illustration 67	g03850115

Illustration 68	g03850117

This signal communicates the actual engine load, as a percentage of the full power rating of the engine. The full power rating will depend on which rating the engine is configured for and can be found in the engine ECM by viewing the "Rating Number" parameter as shown in Illustration 67.

The output is scaled 0-110 percent of engine rating, for 4-20 mA and is torque-based. Engine speed can be used to derive the power being produced by the engine.

Illustration 69	g03857489
With OCP

Illustration 70	g03857491
Without OCP

The signal is available at the EIC and the OCP (if equipped). The connection for this signal is on OCP TB1-28 (+4-20 mA) and OCP TB1-29 (-4-20 mA), or EIC terminals 28 (+4-20 mA) and 29 (-4-20 mA).

Percent of Available Load (Engine Load Factor)

Illustration 71	g03857496
With OCP

Illustration 72	g03857497
Without OCP

This signal communicates the actual engine load, as a percentage of the power capability of the engine under current operating conditions of temperature and cooler performance. The full range (denominator) of the signal varies depending on the inlet manifold air temperature (IMAT) being delivered to the engine. IMAT depends ambient temperature, cooler performance, and engine load.

The output is scaled 0-110 percent for 4-20 mA and is torque-based. The customers control system and operating practices must be designed to keep the Percent of Available Load signal below 100 percent as ambient temperature increases.

The signal is available at the EIC and the OCP (if equipped). The connection for this signal is on OCP TB1-30 (+4-20 mA) and OCP TB1-31 (-4-20 mA), or EIC terminals 30 (+4-20 mA) and 31 (-4-20 mA).

Load Signal Monitoring

Illustration 73	g03850118

The ambient based rating load signals can be viewed in Cat ET under Fuel Flow parameters.

Percent of Max Load is represented by "Actual Engine - Percent Torque"

Percent of Available Load is represented by "Engine Load Factor"

Table 1

Data Link Options - Ambient Based Rating Signals		Data Link	Modbus
Signal Name	Electronic Technician	J1939	OCP	Network Manager (A5N2)
Percent of Max Load	Actual Engine - Percent Torque	SPN:513	40427	44658
Percent of Available Load	Engine Load Factor	SPN:92	40851	40138

Schematic of the Engine I/O

Illustration 74	g03850119