Circuit Breaker
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| Illustration 1 | g00792743 |
Circuit breaker | |
The circuit breakers are used in order to protect the wiring of the circuits. There are three circuit breakers (CB) that are used for the various systems:
CB1 - Circuit breaker 1 protects the following circuits: alarm circuits and shutdown circuits.
CB2 - Circuit breaker 2 protects the control circuits.
CB3 - Circuit breaker 3 protects the circuit for the annunciator, if equipped.
The circuit breakers are equipped with a normally open contact. The breakers also come with an auxiliary normally closed contact. The circuit breakers are rated for 10 amperes.
The circuit breakers will protect the wiring of the circuits. If the current of the circuit exceeds the current rating of the circuit breaker, the breaker will open. The normally closed contacts on the breaker 1 and breaker 2 will activate an alarm indicator.
Relays
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| Illustration 2 | g00793751 |
Relays | |
The relays control the logic for the engine control panel.
The relays are a plug-in type. The relays use a 24 volt coil in order to actuate two set of contacts of a single pole double throw. The contacts are a form C contact which consists of 2 sets of the following terminals: common, normally open and normally closed.
The relays are used to control the operation of the engine control panel. An additional relay is used when additional contacts are required. The additional relay is called an auxiliary relay.
Key Switch (Engine Control)
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| Illustration 3 | g00792845 |
Key switch for the engine control | |
The engine control switch enables the control circuit.
Note: The switch should not be used for normal shutdown.
The switch is a three-position key switch: left, center and right. The positions are labeled from left to right: "OFF/RESET", "LOCAL" and "REMOTE".
"OFF/RESET"
When the switch is in the "OFF/RESET" position, the following operations will be active:
- The key will be allowed to be removed from the switch.
- The engine will not start.
- The active shutdowns will be reset.
"LOCAL"
When the switch is in the "LOCAL" position, the following operations will be active:
- The engine control will be enabled.
- The engine will be allowed to start from the control panel only.
"REMOTE"
When the switch is in the "REMOTE" position, the following operations will be active:
- The engine control will be enabled.
- The engine will be allowed to start from the remote location only.
Switch (Fuel Control)
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| Illustration 4 | g00792908 |
Switch for the fuel control | |
The fuel control switch controls the engine fuel system. The switch also enables the shutdown relays.
Note: The switch is used for normal shutdown.
The switch is a two-position selector switch: left and right. The positions are labeled from left to right: "OFF" and "ON".
The switch can be wired in one of two different configurations for the fuel control.
- energize-to-shutoff "ETS"
- energize-to-run "ETR"
"OFF"
When the switch is in the "OFF" position, the fuel that is supplied to the engine is shut off.
Note: The engine may start when the switch is in the "OFF" position. If rolling the engine is being performed, the "EMERGENCY STOP" switch must also be depressed.
"ON"
When the switch is in the "ON" position, fuel will be supplied to the engine for running.
Switch (Prelubrication)
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| Illustration 5 | g00792951 |
Switch for the prelubrication | |
The prelubrication switch activates the prelube pump.
The switch is only functional when the following conditions are met:
- The engine control switch is in the "LOCAL" position.
- The engine is not running.
- There are no engine faults.
The switch is a three-position selector switch: left, center and right. The positions are labeled from left to right: "PRELUBE", "RUN" and "START". The position is momentary for the "START" position.
"PRELUBE"
The "PRELUBE" position is a maintained position. Turn the switch to the "PRELUBE" position. When the "ENGINE PRELUBE" indicator illuminates, the switch is used in order to start the engine.
"START"
The "START" position is a momentary position. After the "ENGINE PRELUBE" indicator is illuminated, the switch can be held in the "START" position in order to start the engine.
"RUN"
The switch is in the "RUN" position when the switch is not activated. The "RUN" position is the normal position during engine operations.
Push Button Switch (Emergency Stop)
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| Illustration 6 | g00792927 |
Push button switch for the emergency stop | |
Push the red "EMERGENCY STOP" button in order to enable an emergency shutdown. The push button switch for the emergency stop will shut off the fuel supply to the engine. The push button switch will also close the air damper for the inlet air, if equipped.
Note: The switch should not be used for normal shutdown.
The switch is a red mushroom shaped push button. When the switch is depressed, the switch is locked in the "IN" position. The button of the switch must be pulled in order to release the switch to the "OUT" position.
The "IN" position activates an emergency shutdown. The OUT position is for normal engine operation.
Note: When an emergency shutdown occurs and an air damper is present, the air damper must be manually reset before starting the engine.
Switch (Speed Control)
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| Illustration 7 | g00792888 |
Switch for the speed control | |
The speed control switch is used in order to adjust the speed of the engine. This switch is used only on certain types of governors.
The switch is a three-position selector switch: left, center and right. The positions are labeled from left to right: "DECREASE", no label and "INCREASE". The positions are momentary for the "DECREASE" position and the "INCREASE" position.
The switch is in the center position when the switch is not activated.
When the switch is held in the "DECREASE" position, a signal is sent to the governor. The governor will then decrease the speed of the engine.
When the switch is held in the "INCREASE" position, a signal is sent to the governor. The governor will then increase the speed of the engine.
Switch (Governor Mode)
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| Illustration 8 | g00792914 |
Switch for the governor mode | |
The governor mode switch controls the speed of the engine. This switch is used only on certain types of governors.
The switch is a two-position selector switch: left and right. The positions are labeled from left to right: "IDLE" and "RATED".
When the switch is in the "IDLE" position, a signal is sent to the governor. The governor will then set the speed of the engine to an idle speed setting.
When the switch is in the "RATED" position, a signal is sent to the governor. The governor will then set the speed of the engine to the rated speed setting.
Note: The rated speed setting on the 723+ marine governors should be set to match the idle speed setting. This process is performed in order to keep the engine at idle speed when the engine control switch is located in the LOCAL position. See Service Manual, RENR2228, "723 Plus Digital Speed Control" for more information.
Switch (Reset)
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| Illustration 9 | g00792875 |
Reset switch for the annunciator | |
The switch is used in order to clear all of the acknowledged alarms and acknowledged shutdowns. The switch will also clear all of the inactive alarms and inactive shutdowns. The switch is an input to the programmable logic controller.
The switch is a black momentary flush mounted push button. When the switch is depressed, the switch is activated.
Switch (Acknowledged/Lamp Test)
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| Illustration 10 | g00792897 |
Switch for the acknowledge/lamp test | |
The switch is used for the following functions:
- Test the bulbs of all the indicators on the panel.
- Turn the flashing lamps to a solid lamp.
- Silence the horn, if equipped.
The switch is a three-position selector switch: left, center and right. The positions are labeled from left to right: "ACKNOWLEDGE", no label and "LAMP TEST". The positions are momentary for the "ACKNOWLEDGE" position and the "LAMP TEST" position.
The switch is in the center position when the switch is not activated.
When the switch is held in the "ACKNOWLEDGE" position, all the flashing lamps will become solid and the horn will become quiet, if equipped.
When the switch is held in the "LAMP TEST" position, all the indicator lamps on the panel will illuminate except for the engine prelube light.
Liquid Level Switch (Engine Oil)
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| Illustration 11 | g00791739 |
Liquid level switch for the engine oil | |
The liquid level switch monitors the level of engine oil.
The switch is a float switch which uses a set of contacts of a single pole single throw. The orientation of the switch determines the position of the contacts. The system utilizes the normally open contacts.
When a low level of the engine oil is detected, the circuit will enable a timer. If the timer is enabled for a predetermined amount of time, the timer will enable the alarm circuit.
Liquid Level Switch (Engine Coolant)
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| Illustration 12 | g00791760 |
Liquid level switch for the engine coolant | |
The liquid level switch monitors the level of engine coolant.
The switch is a float switch which uses a set of contacts of a single pole double throw. The switch uses the normally closed contacts and the contacts are held open by the liquid.
When a low level of the engine coolant is detected, the alarm circuit will be enabled.
Pressure Switch (Starting Oil)
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| Illustration 13 | g00791797 |
Pressure switch for starting oil | |
The pressure switch monitors the pressure of engine oil for the prelube system.
The switch is a pressure switch which uses a set of contacts of a single pole single throw. The switch is a normally open switch. The contacts will close when the pressure exceeds 9 ± 3 kPa (1.3 ± 0.4 psi).
When a switch is actuated, the circuit will energize the "SOSR" relay. The "SOR" relay will then illuminate the "STARTING OIL PRESSURE" lamp and the relay will also enable the starting circuit for the engine.