Electronic Modular Control Panel II (EMCP II) For MUI Engines Caterpillar

Illustration 1	g00593349
Display Area Of Generator Set Control (GSC) (1) Dedicated shutdown indicators. (2) Fault shutdown indicator. (3) Fault alarm indicator. (4) Upper display. (5) Lower display. (6) Keypad.

The main component of the EMCP II is the generator set control (GSC). The GSC is designed to operate when the GSC is powered by a 24 DCV battery system or a 32 DCV battery system. The GSC monitors many of the functions of the generator set. The GSC has the following functions and features.

• The GSC controls the starting of the engine and the GSC also controls the stopping of the engine.

• The GSC shows engine conditions and generator output information on two displays. The displays also show diagnostic codes and GSC programming information.

• The GSC monitors the system for faults. If a fault occurs, the GSC performs a controlled fault shutdown, or the GSC provides a fault alarm annunciation. The GSC uses indicators and displays to describe the fault to the operator.

• The GSC contains programmable features for certain applications or requirements from customers.

Fault Indicators

The eight fault indicators are used to show that a fault is present. The fault indicators describe the fault. The fault indicators are divided into three groups: fault alarm indicator (3), fault shutdown indicator (2) and dedicated shutdown indicators (1).

The yellow fault alarm indicator (3) FLASHES when the GSC detects an alarm fault. The alarm fault does not cause the engine status to change. The engine will continue to run if the the alarm fault had occurred when the engine was running. The engine will be able to start. Fault alarm indicator (3) is accompanied by a diagnostic code that is shown on upper display (4) when the alarm codes key is pressed.

The red fault shutdown indicator (2) FLASHES when the GSC detects a fault that is a shutdown fault. The engine is shut down if the engine is running. The engine is not allowed to start. Fault shutdown indicator (2) is accompanied by a diagnostic code that is immediately shown on upper display (4).

The red dedicated shutdown indicators (1) represent the following shutdown faults: low oil pressure, emergency stop, high water temperature, engine overspeed, low coolant level and engine overcrank. When the GSC detects a fault in one of these areas, the dedicated fault shutdown indicator that corresponds to the fault FLASHES. If the engine is running, the engine is shut down. The engine is not allowed to start. There are no diagnostic codes that are associated with the dedicated fault shutdown indicators because each indicator has a descriptive label.

Many of the dedicated shutdown faults depend on certain setpoints in the GSC. See Systems Operation, "Engine/Generator Programming OP5". To restart the engine after a shutdown, see Systems Operation, "Shutdown Mode".

The conditions that are required for each dedicated fault are in the following list. The results of each dedicated fault are in the following list.

Low Oil Pressure - The engine oil pressure drops below the setpoints for low oil pressure shutdown that are programmed into the GSC. There are two low oil pressure setpoints. One setpoint is used when the engine is at idle speed. One setpoint is used when the engine is at rated speed. When this fault occurs, the low oil pressure indicator FLASHES. The engine is shut down. The engine is not allowed to start until the fault is corrected.

Emergency Stop - The operator presses the emergency stop push button (ESPB) on the instrument panel. When this condition occurs, the indicator for emergency stop FLASHES. The engine is shut down. The engine is not allowed to start until the condition is corrected.

High Water Temperature - The engine coolant temperature rises above the setpoint for high water temperature shutdown that is programmed into the GSC. When this fault occurs, the high water temperature indicator FLASHES. The engine is shut down. The engine is not allowed to start until the fault is corrected.

Engine Overspeed - The engine speed exceeds the setpoint for engine overspeed that is programmed into the GSC. When this fault occurs, the engine overspeed indicator FLASHES. The engine is shut down. The engine is not allowed to start until the fault is corrected.

Low Coolant Level - The engine coolant level drops below the probe of the optional coolant loss sensor. When this fault occurs, the indicator for the engine coolant level FLASHES. The engine is shut down. The engine is not allowed to start until the fault is corrected.

Overcrank - The engine does not start within the setpoint for total cycle crank time that is programmed into the GSC. When this fault occurs, the overcrank indicator FLASHES. The engine is not allowed to start until the fault is corrected.

Note: The GSC can be programmed to override the shutdown for the following conditions: low oil pressure, high water temperature and low coolant level. When the shutdown faults are overridden then the faults are treated as alarm faults. The corresponding dedicated fault shutdown indicator is ON CONTINUOUSLY instead of flashing. The engine continues to run instead of shutting down. The dedicated fault shutdown indicator that is ON CONTINUOUSLY means that the setpoint for shutdown has been exceeded. However, the GSC is programmed to override the shutdown fault and the GSC treats the fault as an alarm fault. The factory programs the GSC to treat low oil pressure, high water temperature and low coolant level as shutdowns. The operator must make a decision in order to override these shutdown faults.

Display

Illustration 2	g00593349
Display Area Of Generator Set Control (GSC) (1) Dedicated shutdown indicators. (2) Fault shutdown indicator. (3) Fault alarm indicator. (4) Upper display. (5) Lower display. (6) Keypad.

The upper display (4) and lower display (5) of the GSC provide information about the generator set.

Upper display (4) shows AC voltage, current and frequency of one phase of the generator output. Each phase can be viewed one at a time by pushing the phase select key. Upper display (4) is also used to show the various diagnostic codes for system faults. See Systems Operation, "Fault Description" for more information on diagnostic codes.

Lower display (5) shows system battery voltage, engine hours, engine speed, engine oil pressure and engine coolant temperature. The value for one of these conditions is shown for two seconds. The display scrolls to the value for the next condition. A small pointer identifies the engine condition that corresponds to the value that is showing. When the engine meter key is pressed, lower display (5) stops scrolling. The lower display continuously shows one particular value. The pointer flashes above the condition with the value that is showing.

The relay status indicator is on the lower display. When a GSC relay is activated, the corresponding indicator (K1, K2, etc) is shown on lower display (5). When a relay is not activated, the corresponding indicator (K1, K2, etc) is not shown.

Both displays are used for programming functions when you are in service mode. See Systems Operation, "Service Mode" for more information.

Keypad

Keypad (6) is used to control the information that is shown on upper display (4) and lower display (5). The seven keys have two sets of functions, normal functions and service functions. For a description of the service functions of the keys, see Systems Operation, "Service Mode". The normal functions of the keys are in the following list.

Leftmost Key - This key only functions when the GSC is in service mode. See Systems Operation, "Service Mode".

Phase Select Key - This key selects the phase of the generator output that is shown on the GSC. Pressing this key allows the operator to check the voltage, current and frequency of each phase one at a time.

Engine Meter Key - This key stops the scrolling of engine conditions on lower display (5). The display continuously shows the value for one particular engine condition. The pointer flashes in order to indicate that scrolling is stopped. Pressing the key again resumes the scrolling of engine conditions.

Lamp Test Key - This key performs a lamp test on the GSC and the optional alarm module. The eight fault indicators are ON CONTINUOUSLY. Every segment of upper display (4) and lower display (5) are ON. On the optional alarm module, all of the indicators are ON and the horn will sound.

Alarm Codes Key - If fault alarm indicator (3) is FLASHING, pressing this key causes upper display (4) to show the corresponding diagnostic code. Pressing this key again resumes the showing of generator output information on upper display (4). If fault alarm indicator (3) is OFF, this key has no function. See Systems Operation, "Fault Description"for more information on diagnostic codes.

Exit Key - This key only functions when the GSC is in service mode. See Systems Operation, "Service Mode" for more information.

Service Mode Key - Pressing this key causes the GSC to enter service mode. See Systems Operation, "Service Mode" for more information.

Relays

Illustration 3	g00310263
Relay Module On Rear Of GSC

Illustration 4	g00311253
Relays In Relay Module (1) Jumper block.

The relays are located in the relay module on the rear of the GSC. The relays are permanently attached within the relay module and the relays are not removable. The entire relay module is replaced if a relay is faulty. See Testing and Adjusting, "Schematics and Wiring Diagrams (DC Schematics)"for more information.

Some of the contacts of the relays are internally connected to the terminals of the relay module. The contacts are available for the customer to use. The voltage and current specifications for each terminal (relay) are listed in the following table.

Note: Jumper block (1) is used to select the voltage range of the GSC voltmeter. Jumper block (1) is installed for systems with 700 volts full scale AC inputs. Jumper block (1) is NOT installed for systems with 150 volts full scale AC inputs or for any unit with external potential transformers. The relay module comes from the factory with jumper block (1). See Testing and Adjusting, "AC Voltage Range Selection".

K1 Electronic Governor Relay (EGR) - When the relay is active the normally open contacts close. This signals the optional 2301A Governor to accellerate the engine to rated speed. The relay has no normally closed contacts.

K2 Generator Fault Relay (GFR) - When the relay is active the normally open contacts close. This trips the optional circuit breaker when a shutdown fault occurs. The relay has no normally closed contacts.

K3 Crank Termination Relay (CTR) - When the relay is active the normally open contacts close. This activates the optional AUX relay (customer use), and enables an optional goveror switch and the governor synchronizing motor. When the relay is inactive the normally closed contacts close. This enables an optional start aid switch for all engine models except 3500 engines.

K4 Starting Motor Relay (SMR) - When the relay is active the normally open contacts close. This activates the starting motor magnetic switch. This also enables the AUTOMATIC position of the optional starting aid switch for 3500 engines. When the relay is inactive the normally closed contacts close.

K5 Run Relay (RR) - When the relay is active the normally open contacts close. This powers an optional 2301A governor. Also, this activates the MANUAL position of the optional starting aid switch for 3500 engines. When the relay is inactive the normally closed contacts close. These contacts are for customer use.

K6 Air Shutoff Relay (ASR) - When the relay is active the normally open contacts close. This activates an optional air shutoff solenoid during fault shutdowns. When the relay is inactive, the normally closed contacts close. This allows the engine to run.

K7 Fuel Control Relay (FCR) - When the relay is active the normally open contacts close. On ETR systems, this activates the fuel solenoid during starting and running. On ETS systems, this activates the fuel solenoid during shutdown. The relay has no normally closed contacts.

GSC Part Number

Illustration 5	g00310244
Location Of GSC Part Number Rear View Of GSC

Every GSC has a part number that is stamped on the rear housing that is above the harness connector. There have been numerous internal changes in the operation of the GSC. The part number can be used to identify the effectivity of the different changes.