KIT-GASKET 2482093 - Caterpillar

Engine Electrical System
The electrical system has three separate circuits.
Charging circuit
Starting circuit
Low amperage circuitSome of the electrical system components are used in more than one circuit. The following items are common in each of the circuits.
Battery
Circuit breaker
Ammeter
Cables
Wires for the batteryThe charging circuit is in operation when the engine is running. An alternator makes electricity for the charging circuit. A voltage regulator in the circuit controls the electrical output in order to keep the battery at full charge.The starting switch is in operation only when the start switch is activated.The electrical systems include a Diagnostic Connector. The Diagnostic Connector is used to test the charging circuit. The Diagnostic Connector is also used to test the starting circuit.The low amperage circuit and the charging circuit are connected to the same side of the ammeter. The starting circuit connects to the opposite side of the ammeter.Charging System Components
Never operate the alternator without the battery in the circuit. Making or breaking an alternator connection with heavy load on the circuit can cause damage to the regulator.
Alternator
Illustration 1 g00651653
(1) Alternator case ground
(2) Internal ground
(3) "I" terminal
(4) "R" terminal
(5) Output terminal The alternator is a brushless, heavy-duty integral charging system. The alternator has a built-in diode rectifier and a voltage regulator. The system produces DC current for electrical systems.The solid state integrated circuit voltage regulator that is built into the alternator limits the system voltage by switching the ground circuit for the field coil on and off. This is done rapidly in order to control the current that is in the field coil. Nominal regulated voltages of 13.5 to 14.5 volts are available for 12 volt systems. The nominal regulated voltage for the 24 volt system is between 27 and 29 volts.After the engine is started and rpm rises, the excitation circuit is turned on all the time, and generated voltage rises rapidly. If the "I" terminal is not used, the initial field voltages at start-up are generated by residual magnetism. The residual magnetism can be lost. This results in no output. Loss of the residual magnetism can be caused by extended downtime or a severe shock to the alternator. As the speed increases and the output increases, the voltage that is available at the diode trio becomes sufficient to supply field current for normal operation. When the voltage at the "B" terminal exceeds the battery voltage current flows into the battery.The 34SI model has an "I" terminal. The terminal CAN be used in order to supply excitation current. The current flows from a source that has a keyswitch through an indicator light. The indicator light provides a verification for alternator excitation and the light also provides a indication of faults. The "I" terminal must have an indicator or a resistor in series between the current source and the "I" terminal. This maintains the normal field current around 0.17 amperes. Once the alternator begins charging, the field current is supplied from the diode trio. Current stops flowing through the "I" terminal and the indicator lamp turns