SCREEN AS 6E1473 - Caterpillar

Engine Electrical System
The electrical system has two separate circuits.
the charging circuit
the starting circuitSome of the electrical system components are used in more than one circuit. The following items are common in each of the circuits:
The battery
The circuit breaker
The cables
The wires for the batteryThe charging circuit is in operation when the engine is running. An alternator converts mechanical energy to electrical energy for the charging circuit. A voltage regulator in the circuit controls the electrical output in order to keep the battery at full charge.
The disconnect switch, if equipped, must be in the ON position in order to let the electrical system function. There will be damage to some of the charging circuit components if the engine is running with the disconnect switch in the OFF position.
If the engine has a disconnect switch, the starting circuit can operate only after the disconnect switch is put in the "ON" position.The starting switch is in operation only when the start switch is activated.The charging circuit is connected through the ammeter. The starting circuit is not connected through 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 g00292313
Alternator (1) Regulator (2) Roller bearing (3) Stator winding (4) Ball bearing (5) Rectifier bridge (6) Field winding (7) Rotor assembly (8) FanThe alternator is driven by the crankshaft pulley through a belt. When the engine is running, the pulley rotates the shaft inside the alternator. The rotor assembly is attached to the shaft. The rotor assembly has many magnetic poles. The magnetic poles are similar to fingers. An air space exists between each of the opposite poles. The poles have residual magnetism that produces a small amount of magnet-like lines of force (magnetic field). This magnetic field is produced between the poles. As the rotor assembly begins to turn between the field winding and the stator windings, a small amount of alternating current (AC) is produced in the stator windings. The alternating current is produced from the small magnetic lines of force that are created by the residual magnetism of the poles. The AC is changed into direct current (DC) when the current passes through the diodes of the rectifier bridge. Most of this current provides the battery charge and the supply for the low amperage circuit. The remainder of the current is sent to the field windings. The DC current flow through the field windings (wires around an iron core) increases the strength of the magnetic lines of force. These stronger magnetic lines of force increase the amount of AC that is produced in the stator windings. The increased speed of the rotor assembly also increases the current output of the alternator and the voltage output of the alternator.Regulator
Illustration 2 g00360155
Typical regulator assemblyThe voltage regulator is a solid-state electronic switch. The voltage regulator senses the voltage of the system. The regulator then uses switches to control the current to the field windings.