723PLUS Digital Speed Control Caterpillar


Electrical Connections

Usage:

3616 1FN



Illustration 1g00669527

Illustration 1 contains notes for Illustration 2. Illustration 2 represents the wiring diagram for the vessel.




Illustration 2g00669518



Illustration 3g00668625



Illustration 4g00668088



Illustration 5g00668755

The connections for the wiring of the vessel are shown in Illustration 2. The diagram shows the external wiring connections and shielding requirements for the controls. The connections for the control are explained in the rest of this section.

Shielded Wiring

Shielded cable must be twisted into pairs of conductors. Do not attempt to tin the braided shield. To help prevent picking up different signals from adjacent equipment, shield all signal lines. Connect the shields to the nearest chassis ground. Wires that are exposed without shielding should be short. The exposed wire should not exceed 25 mm (1 inch). The other end of the shields must be left open and insulated from any other conductor. Do not run shielded wire along other wires that carry large amounts of current.

Cut the cable to the desired length when the shielded cable is required. Use the steps below to prepare the cable.

  1. Strip the outer insulation from both ends of the cable. Stripping the insulation will expose the braided wrapped shield or the spiral wrapped shield. Do not cut the shield.

  1. Use a sharp, pointed tool in order to carefully spread the strands of the braided shield.

  1. Pull the inner conductors out of the shield. Shields that are braided need to be twisted together. Twisting the shield will help to prevent fraying.

  1. Remove 6 mm (0.25 inch) of insulation from the inner conductors.

  1. Attach proper lugs to the conductors and the shield. Mount the shields to the ground studs of the chassis on the control.

Installations with electromagnetic interference may require additional precautions for shielding. For more information, consult your Caterpillar dealer.

Supply Input (Terminals 1 and 2)

The power supply must be low impedance. For example, battery power may be used. Do not power the control with a high voltage source that has zener diodes and resistors in series with the control power input. The control contains a power supply which requires a current surge to start properly.


NOTICE

To prevent damage to the control, do not use a high voltage power source, and do not use a high voltage source with resistors and zener diodes in series with the power input.


Run the power leads directly from the power source to the control. Do not power other devices with leads that are common to the control. Avoid using long lengths of wire. Connect the positive lead to terminal 1 and negative lead to terminal 2. Be sure to use an alternator or a battery charger in the system if the power source is a battery.

Do not turn off the power to the control as a normal part of the shutdown procedure. Use discrete input 32 for normal shutdown. Leave the control powered except for service of the system and extended periods of nonuse.


NOTICE

Do not apply power to the control at this time. Applying power may damage the control.



NOTICE

To prevent damage to the engine, apply power to the conrol at least 60 seconds prior to starting the engine. The control must have time to perform a self test and become operational. Do not start the engine unless the green "POWER OK" and "CPU OK" indicators on the control cover illuminates. This is because test failure turns off the control output.


Relay Outputs (Terminals "3/4", "5/6", and "7/8")

The three relay outputs provide a normally open contact for controlling three individually controlled devices. These conditions cause the relays to change status: shutdown, alarm and indication. The ratings of the contacts are shown on the specification sheet for the control. See this Service Manual, "Control Specifications" topic. Use interposing relays if the application exceeds these ratings. Each relay is energized when the green light above the respective terminal is illuminated.

The relay contact on terminal "3/4" for Relay Output 1 is used when internal shutdown conditions are meant to externally shut down the engine. Relay Output 1 must be connected to the engine shutdown system in order to execute an engine shutdown. No connection is required if the function for shutdown is not used in the application. The status of the relay changes if a configured shutdown condition occurs. The relay returns to the original status when the condition is cleared and the condition is reset. The contact can be configured as either close on shutdown or open on shutdown. The contact will open if power to the control is lost.

The relay contact on terminal "5/6" for Relay Output 2 is used when the alarm conditions are used by other devices in the application. The status of the relay changes if a configured alarm condition occurs. The relay returns to the original status when the condition is cleared and the condition is reset. The contact can be configured to close for the alarm or the contact can be configured to open for the alarm. The contact will open if power to the control is lost.

The relay contact on terminal "7/8" for Relay Output 3 is used when the conditions of indication are used by other devices in the application. The status of the relay changes if a configured condition of indication occurs. The relay returns to the original status when the condition is cleared and the condition is reset. However, if the relay is configured as a nonlatching output, the condition must only be cleared. The contact can be configured as either a close on indication or a open on indication. The contact will open if power to the control is lost.

For the ratings of the contacts, see this Service Manual, "Control Specifications". Use interposing relays if the application exceeds these ratings.

RS-422 Communication Port J1

The J1 port is intended for use with the programmer. The part number and the part name is 140-2304 Governor Electronic Control Programmer. The programmer may be set up temporarily as a ServLink port by adjusting parameters in the "Communications" menu. See this Service Manual, "Standard Menu Items" for more information.

Speed Signal Inputs 1 and 2 (Terminals 11/12 and 13/14 )

The speed of the engine must be provided to the control by either a passive magnetic speed sensor or an active proximity switch. The device should sense the exact speed of the engine. Caterpillar does not recommend the use of the sensor with the camshaft gear or other gears because of backlash. The engine speed should be between 200 and 2100 rpm.

A second speed sensor may be used for a backup. The sensor may also be used for the filtering of torsional vibration, if necessary. The additional sensor for speed provides a backup for sensing speed if one of the sensors fails. If the two speed sensors are used the sensors must sense the exact same speed of rotation. The usual location for both devices is on the upper half of the flywheel housing.

The input terminals for the speed sensor can be configured to accept signals from the proximity switches. In this configuration, the impedance of the input is at least 2 kê. The proximity switches must be powered by an external source for this configuration.

The input for the speed sensor is configured for a magnetic pickup when the control is shipped from the factory. In this configuration, the impedance of the input could be as low as 200 Ohms. Whenever the engine is controlled, a magnetic pickup that is used as an input for speed must provide a minimum signal of 1.5 Vrms.

The software can be configured for either of two methods for detecting speed: digital and analog. The default is set to detect the speed by the digital method. The same digital method is used on other digital controls that are capable of receiving input frequencies of 90 to 15,000 Hz. An analog method is also available in the software. The analog method of detecting speed can filter out changes in frequency that are caused by the firing of a cylinder. This filter allows the control loop to respond better to changes in engine speed if the firing frequency is within the range of the control loop. The analog method of detection is capable of receiving input frequencies of 250 to 15,000 Hz.

The engine speed must remain between 200 and 2100 rpm during all times of closed loop control.

Two speed sensors must be used if the control is used to monitor torsional vibration. Connect the speed sensor on the engine side of the coupling to terminals 11 and 12 of the "Speed Sensor 1" input. Connect the speed sensor on the loaded side of the coupling to terminals 13 and 14 of the "Speed Sensor 2" input. The speed sensors can be either magnetic pickups or proximity switches.

Use shielded wire for all connections of the speed sensors. Connect the shield to the chassis. Make sure that the shield has continuity to the entire distance of the speed sensor and make sure that the shield has been insulated from all of the other conductive surfaces.

Note: The number of gear teeth is used by the control to convert pulses from the speed sensing device to the engine rpm.

------ WARNING! ------

The engine may overspeed due to incorrect assembly or adjustment.

Engine overspeed could result in personal injury, loss of life and/or property damage.

Be prepared to stop the engine by activating the engine shutdown system or closing the air inlet lines.

----------------------


NOTICE

To prevent possible damage to the control or poor control performance resulting from ground loop problems, use current-loop isolators for any inputs or outputs which connect to non-isolated devices. A number of manufacturers offer 20 mA loop isolators.


Analog Outputs 1 and 2 (Terminals 15/16 and 17/18)

The two analog outputs can be configured different ways. This depends on the needs of the application. The output current can be configured for either 0 to 1 mA or 4 to 20 mA. The current signal is supplied to terminals 15"+" and 16"-" for Analog Output 1 and the current signal is supplied to terminals 17"+" and 18"-" for Analog Output 2. The terminals must be isolated from the ground.

Either of the outputs can be configured in order to perform one of several functions. The functions include the following parameters:

  • Engine Speed

  • Reference for Engine Speed

  • Demand for Fuel

  • Reverse Demand for Fuel

  • Torsional Level

  • Inlet Manifold Air Pressure

  • Lube Oil Pressure

  • Reference for Remote Speed

  • Water Pressure

See this Service Manual, "Control Test and Calibration" for further information on each of these parameters.

Analog Output 1 represents the engine speed. The output is factory set for 4 to 20 mA. The default range is 0 to 1300 rpm. The settings of the software must be changed if the hardware is configured for 0 to 1 mA.

Analog Output 2 represents the reference of engine speed. The output is factory set for 4 to 20 mA. The default range is 0 to 1300 rpm. The settings of the software must be changed if the hardware is configured for 0 to 1 mA.

Use shielded wires that are twisted in pairs. For electrically isolated devices such as 4 to 20 mA analog meters, ground the shield at the control end of the cable. Use the recommendations of the OEM of the device in order to input information to other devices.

Analog Output 3 Terminals 19/20

Analog Output 3 provides a dedicated current signal to a single actuator or two actuators connected in series on a tandem system. This current signal is supplied at terminals 19"+" and 20"-". Software is available to tune the minimum and maximum levels of the actuator stroke. The output current can be configured for either 0 to 200 mA, 0 to 160 mA, or 0 to 20 mA. The 0 to 200 mA range is for standard applications that use a 20 to 160 mA proportional actuator. This range is also for actuators such as the EG3P or the EGB13P. This configuration allows 200 mA into a 40 Ohms impedance. The 0 to 160 mA range is for standard applications that use proportional actuators which are connected in a tandem configuration. This configuration allows 160 mA into a 80 Ohms impedance. The 0 to 20 mA setting can be used as an input to other devices and other actuators. This configuration allows 20 mA into a 10 kê impedance. The software must also be configured to output 4 to 20 mA from the output even though the hardware is configured for 0 to 20 mA. These terminals must be isolated from ground.

Use shielded wires that are twisted in pairs to connect the actuator to the control. For electrically isolated devices such as standard actuators, ground the shield at the control end of the cable. Use the recommendations of the OEM of the device in order to input information to other devices.

Analog Output 4 (Terminals 21/22)

The Analog Output 4 can be configured in different ways. This depends on the needs of the application. The output current can be configured to any of the following ratings: 0 to 200 mA, 0 to 160 mA and 4 to 20 mA. The output of the actuator can be configured in order to perform one of several functions that are similar to analog outputs 1 and 2. The functions include the following parameters:

  • Engine Speed

  • Reference for Engine Speed

  • Demand for Fuel

  • Reverse Demand for Fuel

  • Torsional Level

  • Inlet Manifold Air Pressure

  • Lube Oil Pressure

  • Reference for Remote Speed

  • Water Pressure

Analog Output 4 represents the demand of fuel. The output is factory set for 4 to 20 mA. The default range is 0 to 100 percent.

Note that the selection of the actuator position can be used in order to allow Analog Output 4 to have a signal that is identical to Analog Output 3. Analog Output 4 can be connected to a second actuator by changing the hardware that is configured to 0 to 200 mA. The settings of the software must be changed if the hardware is configured for 0 to 200 mA.

Use shielded wires that are twisted in pairs. For devices that are isolated electrically, ground the shield at the control end of the cable. An example of such device is an analog meter with 4 to 20 mA of input. Use the recommendations of the OEM of the device in order to input information to other devices.

LON 1 and LON 2 (Terminals 23 through 28)

The control provides two separate channels that are used for communicating with Echelon networks. These two ports are not used in this control.

Discrete Inputs (Terminals 29 through 36)

Discrete inputs are the switch commands to the control. The switch input enables control of the engine under a variety of conditions. Refer to this Service Manual, "Description of Operations" for a complete description.

Voltage is supplied to the discrete input terminal when the input closes the switch or a relay contact closes. This causes the input state for that discrete input to be "TRUE". The input terminal has an open circuit when the input opens the switch or a relay contact opens. This causes the input state for that discrete input to be "FALSE". The voltage supply for the discrete inputs should be present from the appropriate terminal when the switch input or the contact of the relay is closed: 29, 30, 31, 32, 33, 34, 35 and 36. Terminal 37 is the common return path for all of the discrete input channels. A lower voltage indicates that the contacts of the switch have high resistance when the switch is closed and the switch should be replaced. These terminals must be isolated from ground. The green light above each input terminal will illuminate for a valid "TRUE" state.

The same external low voltage that powers the discrete inputs may be used to power the control. The voltage source that is used must be capable of supplying 100 mA of current at a voltage level of 18 to 40 VDC. Connect the external low voltage source to terminal 37"-". Connect the external low voltage source to the appropriate switch input or to the appropriate relay contact and connect the mated switch or relay contact to the corresponding discrete input terminal on the control.


NOTICE

Remove the factory installed jumper between terminal 37 and terminal 38 when using external discrete input power.


As an alternative, the discrete inputs may be powered by the internal 24 VDC discrete input power source at terminal 39. This source is capable of supplying 100 mA at a voltage level of 24 VDC. Connect the positive 24 VDC from terminal 39 to the appropriate switch input or to the appropriate relay. Also, connect the mated switch or relay contact to the corresponding discrete input terminal on the control. Ensure that a connection exists between terminal 37 and terminal 38 when the internal discrete input power is used. Do not power other devices with the internal discrete input power source. Ensure that the switch input or the relay contact is isolated from any other circuit.

Fuel Limit Shift (Input A, Terminal 29)

The switch input or the relay contact that is used to activate the Fuel Limit Shift connects to terminal 29. This is discrete input "A". The external switch or relay contact is open during normal operation. The external switch or relay contact is closed only during special conditions when a higher fuel limit is desired. This discrete input will change the status of the control between no fuel limit shift and the fuel limit shift. The control adds a temporary amount of fuel to all fuel limits when the external switch or the relay contacts are closed. This is the fuel limit shift. The amount of fuel and the duration of the additional fuel is adjustable. The normal limits will be restored after the end of the duration. The discrete input is in the "FALSE" state when the contacts open. The amount of fuel that is added is zero and the duration timer will be reset.

Alarm Reset (Input B, Terminal 30)

The switch input or the relay that is used to activate the "Alarm Reset" is connected to terminal 30. This is discrete input "B". This discrete input issues a reset command to all parameters which can latch into an alarm state. The discrete input will be "TRUE" when the external switch or relay contacts are closed. Only those parameters with a normal status will be reset to no alarm condition when the discrete input goes to "TRUE". The internal software limits the duration of the command when the external switch or relay contacts are closed. The reset condition will remain only for a short time within the control even if the external contact remains closed. The discrete input will be "FALSE" when the contacts are open. The control will be ready to respond to closing of the external contacts. The Alarm Reset works in parallel with a switch from the programmer. An automatic reset is temporarily issued for powering up. Also, if the automatic reset is configured, the reset occurs when the engine speed reaches five percent of the rated rpm.

Speed Fail Override (Input C, Terminal 31)

The switch input or the relay that is used to activate the "Speed Fail Override" is connected to terminal 31. This is discrete input "C". The discrete input changes the control operations in order to allow the increase of fuel even though the speed signal is not present. This command is normally used to allow the actuator to open for starting of the engine when the speed signal is too low for detection. Most designs for cranking the engine produce sufficient speed in order for the speed signal to be detected. The override function is not needed with these designs and this input can be left disconnected. The control overrides the shutdown that is associated with losing the speed sensor when the external switch or relay contacts are closed. This discrete input is in the "TRUE" state. The engine will be shutdown by the control when the contacts open. This will occur when both of the speed sensor signals are lost. This discrete input is in the "FALSE" state.

Some systems have a backup mechanical governor that controls the delivery of fuel if the electronic governor fails. For these systems, set the discrete input to the "TRUE" state. This can be done by connecting the input directly to the power source of the positive input. This action forces the demand for fuel to increase if the speed signal is lost. This will also give all control to the mechanical governor. Be sure that the mechanical governor is properly set up to assume control in the event of an electrical system failure. The mechanical governor must not be set up to assume control during normal electric governor operation. Such interaction produces undesirable instability.

Note: The Speed Fail Override command must be "FALSE" during normal operating conditions of the direct-acting systems. This is accomplished by opening the circuit at terminal 31. If the switch or the relay contacts are used to activate this command, the contacts must be designed to open when the engine is running under normal governor control.

------ WARNING! ------

The engine may overspeed due to incorrect assembly or adjustment.

Engine overspeed could result in personal injury, loss of life and/or property damage.

Be prepared to stop the engine by activating the engine shutdown system or closing the air inlet lines.

----------------------

2nd Dynamics (Input D, Terminal)

The switch input or the relay that is used to activate the 2nd Dynamics is connected to terminal 32. This is discrete input "D". This discrete input will change the control operation in order to allow a second set of dynamic terms to be used. This command is normally used when the closed loop path needs two independent sets of dynamics such as a dual fuel engine. The control uses the 2nd Dynamics set when the switch input or relay contacts are closed. The discrete input is in the "TRUE" state. The control uses the 1st Dynamics set when the contacts are open. The discrete input is in the "FALSE" state. No connection needs to be made to this input if only one set of dynamics is used.

Raise Speed Contact (Input E, Terminal 33)

The switch input or the relay that is used to activate the Raise Speed is connected to terminal 33. This is discrete input "E". This discrete input will change the control operations by increasing the reference of the speed. The reference can be increased only to a maximum speed limit that is adjusted by the software. The reference will be increased at a rate that is adjusted by the software.

The following two methods will remove control from the Raise Speed command. The command will be effectively disabled:

  • Use of the "LOWER SPEED" command

  • The "RATED SPEED" command is not selected.

This command is normally used in order to allow increasing the engine speed manually. The command is also used for testing high speed operations such as an overspeed condition. The control increases the reference of the speed when the external switch or the relay contacts are closed. The discrete input is in the "TRUE" state. The increase in speed is limited to the maximum speed limit that is adjusted by the software. The status of the discrete input will be "FALSE" when the contacts are open. The control will stop increasing the reference of the speed.

Lower Speed Contact (Input F, Terminal 34)

The switch input or the relay that is used to activate the Lower Speed is connected to terminal 34. This is discrete input "F". This discrete input will change the control operation by decreasing the reference of the speed. The reference can be decreased only to a minimum speed limit that is adjusted by the software. The reference will be decreased at a rate that is adjusted by the software.

Control is removed from the Lower Speed command if the "RATED SPEED" command is not selected. The command will be effectively disabled.

  • The "RATED SPEED" command is not selected.

This command is normally used in order to allow decreasing the engine speed manually. The command is also used for testing low speed operations such as critical speeds. The control decreases the reference of the speed when the external switch or relay contacts are closed. The discrete input is in the "TRUE" state. The decrease in speed is limited to the maximum speed limit that is adjusted by the software. The control stops decreasing the reference of the speed when the contacts open. The discrete input is in the "FALSE" state.

Remote Speed Reference Contacts (Input E, Terminal 33 and Input F, Terminal 34)

The Raise Speed contact in conjunction with the Lower Speed contact is used to select the Remote Speed Reference. Discrete input "E" is used for the Raise Speed. Discrete input "F" is used for the Lower Speed. The Remote Speed Reference is active when both of the switch inputs and relay contacts are closed. Both of the discrete inputs are the "TRUE" state.

Rated Speed (Input G, Terminal 35)

The external contact that is used to activate the Rated Speed is connected to terminal 35. This is discrete input "G". This discrete input will change the control operation by changing the reference of the speed to rated speed or to idle speed. The reference of the speed ramps for a time that is set by the Acceleration Time to the rated speed control point when the switch input or the relay contacts are closed. The discrete input is in the "TRUE" state. The Raise Speed contact, the Lower Speed contact, and the Remote Speed Reference are enabled.

The reference of the speed ramps for a time that is set by the Deceleration Time to the idle speed control point when the switch input or the relay contacts are open. This discrete input is in the "FALSE" state. The Raise Speed contact, the Lower Speed contact, and the Remote Speed Reference are disabled. The Rated Speed input can be left in the "TRUE" state at all times if the application does not require an idle speed setting. This can be done by connecting the input directly to the positive power source of the Discrete Input.

Open to Run (Input H, Terminal 36)

The external contact that is used to activate the Open to Run is connected to terminal 36. This is discrete input "H". This discrete input will change the control operation by using one of the following methods:

  • The input increases the Minimum Fuel Function in order to allow other functions to control the demand for fuel.

  • The input decreases the fuel to zero.

The discrete input is in the "FALSE" state when the switch input or the relay contacts are open. The Minimum Fuel function is increased to 100 percent. This discrete input is in the "TRUE" state when the switch input or the relay contacts are closed. The Minimum Fuel function will immediately change the demand for fuel to zero.

The Open to Run is the preferred means for a normal shutdown of the engine. The output of the control to the actuator is minimum when voltage is applied to terminal 36.

Note: The "Open to Run" input is not intended for use as the main means of shutdown in any emergency stop. DO NOT use the "Open to Run" input as the main means of shutdown in any emergency stop.

------ WARNING! ------

The engine may overspeed due to incorrect assembly or adjustment.

Engine overspeed could result in personal injury, loss of life and/or property damage.

Be prepared to stop the engine by activating the engine shutdown system or closing the air inlet lines.

----------------------

Lube Oil Pressure Input (Signal Input 1, Terminals 42/43)

Connect the transmitter for Lube Oil Pressure to Signal Input 1. The input signal must be an isolated signal of high quality that represents the signal for Lube Oil Pressure. This signal input can provide the engine with the following protection:

  • an alarm

  • a shutdown

  • both an alarm and a shutdown

The oil pressure is displayed on the programmer in units that can be programmed in the software. The oil pressure may be transmitted through one of the analog outputs to any external devices such as a meter or a recorder. The default setting of the units is 0 to 100 psig. Engine alarms and shutdown are also displayed on the programmer. No connection is required to this input if this function is not needed by the application.

A shutdown condition activates Relay Output 1. Relay Output 1 must be connected to the engine shutdown system in order to execute an engine shutdown if this function is needed by the application. An engine alarm will activate Relay Output 2. Relay Output 2 may be used if the engine alarm is needed by the application.

Use a shielded cable that is twisted in pairs to connect to one of the following items to terminals 42 "+" and 43 "-":

  • a 4 to 20 mA current transmitter

  • a 1 to 5 VDC voltage transmitter

The jumper wire between terminals 41 and 42 must be removed when a voltage transmitter is used. An input impedance of 250 ê is present when the jumper is installed. The input impedance is greater than 10 M ê when the jumper is not installed. This signal is not isolated from the other signals of the control. A device must be used to isolate the signal if the output of the transmitter is not isolated.

A failure of the input signal will be detected for the following values:

  • less than 2.0 mA (0.5 VDC)

  • greater than 21 mA (5.25 VDC)

A detected failure will cause a Status Indication alarm. The alarm will continue until repairs are made.

Water Pressure Input (Signal Input 2, Terminals 45/46)

Connect a Water Pressure transmitter to Signal Input 2. The input signal must be an isolated signal of high quality that will represent the signal for the Water Pressure. This signal input can provide the engine with the following protection:

  • an alarm

  • a shutdown

  • both an alarm and a shutdown

The water pressure is displayed on the programmer in units that can be programmed in the software. The water pressure may be transmitted through one of the analog outputs to any external devices such as a meter or a recorder. The default setting of the units is 0 to 100 psig. Engine alarms and shutdown are also displayed on the programmer. No connection is required to this input if this function is not needed by the application.

A shutdown condition activates Relay Output 1. Relay Output 1 must be connected to the engine shutdown system in order to execute an engine shutdown if this function is needed by the application. An engine alarm will activate Relay Output 2. Relay Output 2 may be used if the engine alarm is needed by the application.

Use a shielded cable that is twisted in pairs to connect one of the following items to terminals 45 "+" and 46 "-":

  • a 4 to 20 mA current transmitter

  • a 1 to 5 VDC voltage transmitter

The jumper wire between terminals 44 and 45 must be removed when the voltage transmitter is used. An input impedance of 250 ê is present when the jumper is installed. The input impedance is greater than 10 M ê when the jumper is not installed. This signal is not isolated from the other signals of the control. A device must be used to isolate the signal if the output of the transmitter is not isolated.

A failure of the input signal will be detected when the values of the input are less than 2.0 mA (0.5 VDC). A failure of the input signal will be detected when the values of the input exceed 21 mA (5.25 VDC). A detected failure will cause a Status Indication alarm and a failure will continue to be a Status Indication alarm until the repairs are made.

Air Manifold Pressure Input (Signal Input 3, Terminals 48/49)

Connect an Air Manifold Pressure transmitter to Signal Input 3. The input signal must be an isolated signal of high quality that will represent the signal for the Air Manifold Pressure. This signal input allows the signal pressure of the air manifold to limit the demand for fuel. The pressure of the air manifold is displayed on the programmer in units that can be programmed in the software. The pressure of the air manifold may be transmitted through one of the analog outputs to any external devices such as a meter or a recorder. The setting of the units is 0 to 50 inches Hg. No connection is required to this input if this function is not needed by the application.

Use a shielded cable that is twisted in pairs to connect one of the following items to terminal 48 "+" and 49 "-":

  • a 4 to 20 mA current transmitter

  • a 1 to 5 VDC voltage transmitter

The jumper wire between terminals 47 and 48 must be removed when the voltage transmitter is used. An input impedance of 250 ê is present when the jumper is installed. The input impedance is greater than 10 M ê when the jumper is not installed. This signal is not isolated from the other signals of the control. A device must be used to isolate the signal if the output of the transmitter is not isolated.

A failure of the input signal will be detected for the following values:

  • less than 0 mA (0.5 VDC)

  • greater than 21 mA (5.25 VDC)

A detected failure will cause a Status Indication alarm. The alarm will continue until the repairs are made.

Remote Speed Reference Input (Signal Input 4, Terminals 51/52)

Connect a transmitter for the Remote Speed Reference to Signal Input 4. The input signal must be an isolated signal of high quality that will represent the signal for the Remote Speed Reference. This signal input can allow the Remote Speed Reference to change setpoints. The loss of the signal will provide the engine with the following protection if the control is configured:

  • an alarm

  • a shutdown

  • both an alarm and a shutdown

The remote speed reference is displayed on the programmer in the software. The remote speed reference may be transmitted through one of the analog outputs to any external devices such as a meter or a recorder. The default setting of the units is 0 to 1200 rpm. The Remote Speed Reference is activated when the "Raise" and the "Lower" have a simultaneous closing and the "Raise" and the "Lower" remain closed. These discrete inputs are terminals 33 and 34. The Rated Speed input must be closed in order to permit Remote Speed Reference control. The Rated Speed input is input "G" (terminal 35). No connection is required if this function is not needed by the application.

A failure of the input signal will be detected for the following values:

  • less than 2.0 mA (0.5 VDC)

  • greater than 21 mA (5.25 VDC)

A detected failure will cause a Status Indication alarm. The alarm will continue until repairs are made.

Note: The reference of the speed will ramp to a minimum speed if the Remote Speed Reference is selected and the input goes below 2 mA. A shutdown will occur if the control is configured for a shutdown. The default is not set to shutdown.

Communication Port J2

The J2 port is configured as a ServLink port for Watch Window and Control View PC programs. The default is configured with a RS 232, that has 19200 baud. The hardware can be configured for RS 422 and a wide range of baud rates. See this Service Manual, "Standard Menu Items" for more information.

Communication Port J3

The J3 port is a spare that has not been configured.

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3512B Engine for SPF343, SPS343, and SPT343 Pumpers Electrical Connectors and Functions
3456 Engine, 836G Landfill Compactor, 834G Wheel Dozer and 988G Wheel Loader CID 0273 FMI 04 Turbo Outlet Pressure short to ground
3500B and 3500B High Displacement Generator Set Engines Electronic Service Tools
3456 Engine, 836G Landfill Compactor, 834G Wheel Dozer and 988G Wheel Loader CID 0274 FMI 13 Atmospheric Pressure calibration required
3512B and 3516B High Displacement Locomotive Engines Model View Illustrations
3512B Petroleum Engines Fuel Pressure
C-9 Engine for TK711, TK721, TK722, TK732, TK741, TK751, and TK752 Track Feller Bunchers CID 0268 FMI 02 Check Programmable Parameters
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