Engine Supervisory System (ESS) Panel

Location Of Components

Engine Supervisory System (ESS) Panel Location Of Components
(1) Junction box. (2) Status control. (3) Mode control switch. (4) Emergency stop push button.

The Engine Supervisory System (ESS) Panel contains the Engine Status Control Module (SCM), an Emergency Stop Push Button (ESPB) and a Mode Control Switch (MCS).

The Engine Status Control Module (SCM) is used to monitor engine parameters (oil pressure, coolant temperature, engine overspeed and over cranking of the starting motor), provides an engine protection system (two stage shutdown) and controls normal start/stop functions.

An Emergency Stop Push Button (ESPB) is located on the remote control panel. When this button is pressed, the fuel is shut off and the engine ignition is turned off.

The Mode Control Switch (MCS) has four positions - "Off/Reset, Auto, Start and Stop".

Components On The Back Of SCM
(5) Fuses (F1 through F8). (6) Switch (overspeed verify).

Function Of Controls

When the Emergency Stop Push Button (ESPB) is pressed, the gas shut-off valve is de-energized which stops the fuel supply to the engine. At the same time a relay is energized to turn the ignition off (the ground to the shutdown switch of the Electronic Ignition System control is opened).

To restart the engine, the emergency stop push button (ESPB) must be turned until it pops out. Above the emergency stop push button is the Mode Control Switch (MCS).

The MCS determines the status of the remote control panel. In the automatic position (12 o'clock), the engine will start automatically whenever the remote initiating contact (IC) (optional) is closed and prelube is complete. The engine will also shut down after the initiate contacts open. An adjustable cool down time can be programmed to give a 0 to 30 minute cool down period before the engine shuts down. In the start position (3 o'clock), the engine will prelube, start and run as long as the MCS is in this position. In the stop position (6 o'clock), the fuel solenoid shuts the engine down after cool down. In the off/reset position (9 o'clock), the fault lights are reset and engine shuts down immediately. The power will be removed from the ESS as soon as the postlube cycle is complete.

Engine Status Control Module

The bottom of the ESS panel contains the Status Control Module. This displays fault conditions and key engine parameters.

The Engine Status Control Module (SCM) accepts information from the operator, magnetic speed pickup (MPU), pressure/temperature module and the Engine Supervisory System. This information is used to determine the "on/off" state of the engine's fuel and ignition system.

Engine Status Control Module (SCM)
(1) Display LCD. (2) Switch (display hold switch). (3) Low oil pressure LED. (4) Overcrank LED. (5) Overspeed LED. (6) High oil temperature LED. (7) Emergency stop LED. (8) Auxiliary shutdown.

In the very basic operating conditions, the SCM receives a signal to run the engine. The SCM then turns on the engine's fuel and starting motor. When the engine speed reaches the crank termination speed, the starting motor is disengaged. When the SCM receives a signal to stop the engine, it shuts the fuel off.

Cycle Crank - The SCM can be programmed to crank-rest-crank for adjustable time periods (see Service Procedure A for adjusting).2301A Speed Control - When the engine oil pressure increases past the low oil pressure set point, the SCM will indicate to the SIEC that it should increase the engine speed from idle to rated.Cooldown - Upon receiving a signal to perform a normal shut down, the SCM will wait a preprogrammed amount of time before shutting the engine off by means of the gas shut-off valve.Automatic Operation - While in the automatic mode, the SCM can be started by a remote initiate signal [when initiate contact (IC) closes]. Upon loss of the signal, the SCM will perform a normal shut down.Alarm Module Communication - The SCM can transmit fault and alarm conditions to an alarm module.Power Down - The ESS Panel system is designed to remove power when in the off/reset mode once the postlube cycle is complete. The SCM will not allow the power down until the Crank Termination Relay and the Fuel Control Relay are both "off" (both relays turn off two seconds after zero rpm).Fuel Solenoid Type - The SCM can be programmed to work with either an Energize To Run (ETR) fuel system or an Energize To Shutdown (ETS) fuel system. In G3600 applications this must be an ETR system.LED Display - Six LEDs are located on front of the SCM to annunciate overcrank shutdown, overspeed shutdown, low oil pressure shutdown, high oil temperature shutdown, emergency stop and auxiliary shutdown.Emergency Stop - If the SCM detects an emergency stop, the engine will shut down by means of ignition and fuel control. LED (7) will flash.Pressure/Temperature Module Malfunction - If the signal from the engine mounted oil pressure/temperature transducer module is lost or unreadable, the engine will be shut down by means of the fuel control and a diagnostic code will be displayed. The SCM can be programmed to ignore the transducer module malfunction.Speed Pickup Malfunction - If the SCM loses its magnetic pickup signal, the engine will be shut down by means of the ignition system and fuel control and a diagnostic code will be displayed.Overcrank Protection - If the engine fails to start in a preprogrammed amount of time, the SCM will halt the starting sequence and flash an LED (4). Another attempt at starting the engine cannot be made without first going into the off/reset position on the MCS.Liquid Crystal Display (1) - Service hours, engine speed, system battery voltage, engine oil pressure and engine oil temperature are sequentially displayed in either English or metric units. Pressing switch (2) on the front of the SCM will cause the display to lock (stop) on one of the engine parameters. Pressing the switch again will resume the display to normal sequencing. When a fault signal is detected, the display is also used to indicate diagnostic codes, to aid in troubleshooting. In the Troubleshooting Section, see Diagnosed Problems.

NOTE: All diagnostic lights should turn on briefly when the panel is powered up. This is a lamp test.Overspeed Protection - If the engine speed exceeds the overspeed set point, it will be shut down by means of ignition and fuel control. LED (5) will flash. The overspeed set point is lowered to 75 percent of its original value while the overspeed verify switch is depressed. This will allow the overspeed circuit to be tested while the engine is operating at rated speed. See Service Procedure F for testing.Low Oil Pressure Protection - If the engine oil pressure drops below the low oil pressure set point, it will be shut down by means of the fuel control. LED (3) will flash. There are two low oil pressure set points, one for when the engine speed is below the oil step speed and another for when the engine speed is above the oil step speed. See Service Procedure H for testing.High Oil Temperature Protection - If the engine oil temperature exceeds the high oil temperature set point, the engine will shut down by means of the fuel control. LED (6) will flash. See Service Procedure G for testing.

NOTE: For all fault conditions, if the fuel control fails to shut down the engine, the ignition system is shut off five seconds after the fault occurs.

Sequence Of Operation

The Mode Control Switch (MCS) of the remote control panel has four positions - "AUTO, START, STOP, OFF/RESET". If the MCS is in the "AUTO" position and a signal to run is received from a remote initiate contact (IC), or the MCS is placed in the "START" position, the engine will prelube, crank, terminate cranking and run. The engine may cycle crank if the cycle crank feature is utilized. The engine will run at low idle speed until lube oil pressure has exceeded the idle low oil pressure set point, then the 2301A Speed Control relay contact of the SCM will close and the engine will accelerate to rated speed. The engine will run until the signal to run is removed by either turning the Mode Control Switch (MCS) to "STOP", "OFF/RESET", or opening the remote initiate contact with the MCS in the "AUTO" position. Once the MCS is moved to the "STOP" position, or if in the "AUTO" position and the remote initiate contact opens, the engine will run for a short period of time in the cool down mode, if the cool down feature was utilized. If the cool down feature was not utilized the engine will shut down immediately. The engine will then start the postlube cycle. The engine is then capable of immediate restart.

Sequence Of Operation (Normal Start-Stop)

Upon receipt of a signal to start, the SCM will check to assure that:

a. An emergency stop signal is not present.

b. All faults have been reset.

c. All sensors are connected and operating properly.

d. No abnormal mode control switch signals are present.

e. The engine is not already running.

f. The SCM microprocessor is functioning properly.

g. The SCM is not in the programming mode.

The SCM will not allow the start sequence to begin and will display the proper diagnostic code when applicable, if an above fault condition exists. However, once the SCM is satisfied that conditions are normal, it will energize the Starting Motor Relay (SMR) and Run Relay (RR). The SCM will also signal for fuel to be turned on by energizing the Fuel Control Relay (FCR) and Run Relay (RR). If the cycle crank feature is enabled, the SCM will automatically crank-rest-crank the engine for adjustable time periods. If the engine fails to start within the selected total crank time, the SCM will execute an overcrank fault. If a fault condition occurs while the engine is cranking, the SCM will terminate and lock out cranking and display the applicable diagnostic code, or light the appropriate LED.

After the engine starts and has achieved the proper crank termination speed, the SCM will de-energize the starting motor by de-energizing SMR and will energize the Crank Termination Relay (CTR). Once the correct low idle oil pressure is achieved, the SCM will signal for the SIEC to accelerate the engine to rated speed, by energizing the 2301A relay.

The engine will run as long as operating conditions remain normal and a signal to run is being received by the SCM. The SCM will sequentially display (each for a two second period) the engine oil pressure, oil temperature, rpm, service hours, and system DC volts; by means of the digital display prior to or while the engine is operating; as well as monitor for any fault or abnormal conditions that may occur.

Upon loss of the run signal, the engine will continue to run for an adjustable cool down period if the cool down feature is utilized. However, if the cool down feature is not used or if the SCM receives an off/reset signal, it will immediately de-energize the Run Relay. The fuel circuitry will be de-energized If the signal to run returns before the engine stops, the SCM will immediately go back to the running state, (ie, fuel will be turned back on, but the starting motor will not energize). However, if restart does not occur and rpm continues to drop, the SCM will initiate cranking upon reaching zero rpm.

Assuming that the run signal does not return and the engine speed continues to diminish until zero rpm is reached, the Crank Termination Relay (CTR) will be de-energized and the SCM will be ready for an instant restart. The Fuel Control Relay will be ready for an instant restart. The Fuel Control Relay (FCR) of the SCM will de-energize two seconds after zero rpm.

Sequence Of Operation (Fault Conditions)

If a fault condition occurs prior to starting the engine, the SCM will:

a. De-energize and lock out the starting motor circuit.

b. Assure that fuel is shut off.

c. De-energize the Run Relay Circuit.

d. Energize the fault shutdown circuitry, Engine Failure Relay (ENFR).

If a fault condition occurs while the engine is running, the SCM will respond as follows:

e. Fuel control circuitry will be de-energized for energized to run engines.

f. Magneto Shutoff Relay (MSR) will be de-energized, for an overspeed, emergency stop, or diagnostic codes 01, 04, 06 or if all six LED's are on. The MSR will also de-energize if the engine has not shut down within five seconds after the FCR commanded it to do so as a result of a fault condition. The MSR circuitry shall be re-energized 10 to 15 seconds after the engine reaches zero rpm. The MSR shuts off the ignition system.

g. The Starting Motor Relay (SMR) circuitry shall be locked in the de-energized state.

h. The Run Relay (RR) circuitry shall be de-energized.

i. The Fault Shutdown Circuitry shall be energized, including the Engine Failure Relay (ENFR).

If a fault occurs before or after the engine starts, the appropriate fault indicating LED shall flash at two Hz or a diagnostic code shall be displayed to indicate the nature of the problem. The indicators shall remain on and the SCM shall remain in the fault mode until it receives a reset signal.

Pressure/Temperature Module

The pressure/temperature module receives engine oil temperature and engine oil pressure information. The pressure/temperature module then sends engine oil temperature and engine oil pressure information to the SCM.

Current Pressure/Temperature Module
(1) Connector to SCM. (2) Connectors to oil temperature sensor. (3) Connector to engine oil pressure sensor.

On the pressure/temperature modules, the engine oil pressure transducer is NOT mounted within the module. Wires connect the module to the engine oil pressure sensor. The engine oil pressure sensor contains the transducer and mounts to the engine. Wires also connect the module to the engine oil temperature sensor and the SCM.

Optional Modules

Alarm Modules

Alarm Module (NFPA 110 ALM)
(1) Amber LEDs. (2) Red LEDs. (3) Horn. (4) Acknowledge/silence switch.

The alarm module (ALM) is an attachment located on the remote control panel face. Red LEDs (2) and amber LEDs (1) are the visual indicators. Horn (3) is the audible indicator.

There are four versions of the basic module. The modules are either alarm modules or a remote annunciator. The nomenclature remote annunciator is required but, it is the same basic module. The versions are:

* Standby NFPA 99 alarm module.

* NFPA 99 remote annunciator, used with standby NFPA 99 alarm module.

* Standby NFPA 110 alarm module, used with NFPA 110 remote annunciator panel. See Remote Annunciator Panel (NFPA 110).

* Prime power alarm module.

The only differences between these modules is in the graphics film on the front of the panel and the jumper wires on the rear. The NFPA 99 remote annunciator also has a lamp test switch. The following description of operation refers to the alarm/remote annunciator module as the annunciator module.

The purpose of the alarm modules (ALM) is to give a warning of conditions that are becoming a problem before conditions are bad enough to shut down the engine or keep it from starting.

If, with the MCS in the STOP or AUTO positions, an alarm condition develops prior to or while the engine is running, that condition is indicated by the optional alarm module and/or the remote annunciator.

Description Of Operation

NOTE: In the following description the word annunciator is used to mean either the alarm module or remote annunciator module.

The annunciator module receives data from three sources: switch inputs, internal circuitry, and a serial data link from the status control module (SCM).

Switch Inputs

Up to four inputs are available for switch (ie, Low Fuel Level) connections. Switch inputs are activated when connected to battery negative (-B). See Table 1.

Internal Circuitry

Internal circuitry is used to determine and annunciate if the DC battery supply voltage is below the set point (factory set at 24 VDC).

Data Link

The annunciator module receives data from the engine Status Control Module (SCM) by means of a serial data link. The information included in this data stream includes:

1. Oil temperature has exceeded the high temperature alarm set point programmed into the SCM.

2. Oil pressure is below the low oil pressure alarm set point programmed into the SCM.

3. Oil temperature is below the low temperature alarm set point programmed into the SCM.

4. The mode control switch is not in the "AUTO" position.

5. Oil pressure is below the low pressure shutdown set point programmed into the SCM.

6. Oil temperature has exceeded the high oil temperature shutdown set point programmed into the SCM.

7. The engine failed to start (overcrank).

8. The engine speed exceeded the overspeed set point programmed into the SCM.

9. The engine shut down due to a remote fault condition.

10. The engine shut down due to a spare fault condition.

11. The engine shut down due to an emergency stop condition.

12. The engine shut down due to a diagnostic fault condition.

Data items 1 through 8 control the operation of the LEDs and the horn as indicated in TABLE 1. Data items 9 through 12 control the operation of the horn only.

The maximum number of modules or alarms connected to the serial link is three. The maximum distance between a module and the SCM is 305 m (1000 ft).

LED And Horn Function

LED And Horn Operation

When an alarm condition occurs, the LED corresponding to that condition will flash at two hertz and the horn will sound. If the alarm condition is "NOT LATCHED", the LED and horn will turn off as soon as the alarm condition ceases. If the alarm condition is "LATCHED", the LED will continue to flash until the acknowledge/silence input is activated. See TABLE 1 for "LATCHED" alarm conditions, LED and horn functions for each operating mode.

Acknowledge/Silence

Activating the acknowledge/silence switch (4) causes the horn to cease and the LED to stay on continuously.

Data Link Malfunction

If the data link malfunctions, the LEDs controlled by the data link will flash at 0.5 hertz. The switch controlled LEDs will function normally.

Lamp Test

Activating the lamp test switch will result in the horn sounding and turning on all the LEDs continuously for ten seconds or until the switch is deactivated.

Mode Selection

The annunciator module operates in one of the five modes described in TABLE 2. The modes are selected by connections made to the mode select inputs (terminals 5 and 6) and switch 2 input (terminal 9) as shown in TABLE 2.

Mode Selection And Switch Input Connections

Remote Annunciator Panel - NFPA 110

Alarm Module (NFPA 110 ALM)
(1) Amber LEDs. (2) Red LEDs. (3) Horn. (4) Acknowledge/silence switch.

NFPA 110 Remote Annunciator Panel
(5) Trouble light. (6) Horn. (7) Acknowledge/silence switch.

This remote panel functions in conjunction with the NFPA 110 alarm module. When an alarm occurs on the alarm module or a fault occurs on the ECM, horns (3) and (6) sound in both the alarm module and the remote annunciator. Trouble light (5) lights in the remote annunciator panel. The appropriate alarm LED also lights in the alarm module or the appropriate fault LED lights on the status control module (SCM).

When alarm acknowledge/silence switch (4) or (7) is pressed on either the remote panel or the alarm module, the horns on both cease sounding. Also, trouble light (5) on the remote panel goes out. The LED on the alarm module or SCM remains on. Another fault or alarm condition reactivates the horns, LED and light as before.