Switches
Inside the electronic instrument panel in the upper left hand corner, there are three switches. The switches are used to perform the functions below for Generator Set applications.
- Manual Start Crank Switch (MANCS) (2)
- Overspeed Verify Switch (OSS) (3)
- High/Low Idle Switch (LIS) (1)
For marine applications, the switches are used for the functions that are listed below.
- Manual Start Crank Switch (MANCS) (2)
- Overspeed Verify Switch (OSS) (3)
- Prelube Override Switch (PLOS) (1)
- Engine Protection Override Switch (EPOS) (4). This switch is used on marine propulsion engines that were built after April 1997 only.
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| Illustration 1 | g00526769 |
Note: The Prelube Override Switch is present only if the prelube pump (attachment) is part of the engine package. The parameter of the prelube pump must be turned ON by the electronic service tool for this function to work.
The MANUAL START CRANK SWITCH (2) permits cranking of the engine by the operator while other controls or protection systems are being overridden. Therefore, the starting motors can be engaged even when the engine control switch is in the OFF/RESET position. Also, the starting motors can be engaged when the engine ECM has completed the cycle crank sequence or when the engine ECM has completed a remote shutdown command. The "Manual Start Crank" switch has the following uses.
- System troubleshooting
- Engine maintenance
- On engines that are equipped with two electronic control modules, the switch will restart the engine when the backup engine control module (ECM) is in control. the switch will restart the engine.
Only marine propulsion engines are equipped with more than one ECM (two). Otherwise, the Manual Start Crank switch should not be used for normal operation of the engine.
Note: The Manual Start Crank Switch must be used to start the engine when the backup ECM is in control.
The Engine Protection Override Switch allows the operator to override the strategies for protection of the propulsion engine Caterpillar Monitoring System. The switch is provided for use in emergency situations when the engine must be operated at full capacity immediately. The switch may be used during a derate condition or a shutdown condition. The switch may not be used during an overspeed shutdown. The switch may also be used to prevent an engine shutdown during critical maneuvers.
The Engine Protection Override Switch is a two-position ON/OFF switch. When the Engine Protection Override Switch is in the OFF position, the Caterpillar Monitoring System will operate normally.
When the Engine Protection Override Switch is in the ON position, the Engine Protection Override Switch is disabled. The warnings and the overspeed shutdown will continue to function normally. When the Engine Protection Override Switch is in the ON position, the engine will perform as though there are no active derates or no active shutdowns. If the engine has already had a shutdown, the engine can be restarted. The alarm conditions and the events will continue to function normally.
When the Engine Protection Override Switch is placed in the ON position, an event will be logged in the ECM. An event will be logged in the ECM when the switch is returned to the OFF position. No delay is required for use of the Engine Protection Override Switch.
The OVERSPEED VERIFY Switch (3) allows the operator to verify that the overspeed protection system is properly working. When the switch is activated, the engine ECM will perform an engine overspeed shutdown at 75 percent of the engine overspeed trip point. The overspeed verify switch is intended to be used for troubleshooting and verification of engine protection systems.
The "HIGH/LOW" Idle Switch (1) allows the operator of the Generator Set to hold the engine speed at the low idle setting. The electronic service tool is used to program the low idle setting. When the "HIGH/LOW" Idle Switch is activated, the engine speed will be governed at the low idle setting. If the "HIGH/LOW" Idle Switch is deactivated, the engine speed will be governed to the high idle setting. The "HIGH/LOW" Idle Switch is intended to be used for troubleshooting.
The PRELUBE OVERRIDE Switch (1) allows the operator of a marine propulsion engine to override the prelube pump sequence during normal engine start-up. The override will occur if there is an attached prelube pump as part of the engine system. The engine ECM will not initiate an engine prelube sequence prior to cranking the engine, when the prelube override switch is activated. The engine ECM will immediately begin to crank the engine without prelubing first. The prelube override switch is intended to be used for immediate engine starting during emergency situations.
Note: Inside the Locomotive Junction Box, there is one switch in the middle of the box. The switch is used for verification of engine overspeed.
Circuit Breakers, Relays, and Wiring
A number of circuit breakers are inside the electronic instrument panel that are used to protect the electrical system and the electrical wiring. The following circuits are protected by circuit breakers.
- starting circuit
- battery circuit
- relay circuit
- starter relay circuit
- ECM circuit
- Programmable Relay Control Module (PRCM)
- "DeNOx" (non-marine Generator Set only)
- main display module circuit
- control switch circuit
- alternator circuit
- customer power circuit
- secondary ECM circuit
Relays are used in order to control the following subsystem power requirements.
- mag relays for starter circuits
- relays for air shutoff circuits (not available on Locomotive)
- master relays and slave relays for prelube pump circuits (attachment) (not available on Locomotive)
- relay for the main display module circuit (not available on Locomotive)
- relay for ECM circuit (not on Locomotive)
- relay for secondary ECM circuit (Marine only)
- relays for ether starting aid pull-in circuits and ether hold-in circuits (non-marine Generator Sets only) (attachment)
- shutdown notify
- Programmable Relay Control Module (PRCM) (not on Locomotive)
- "DeNOx" (non-marine Generator Set only) (attachment)
- customer power (marine only) (not on Locomotive)
- General Alarm (Locomotive only)