SLIP JOINT GP 9V1939 - Caterpillar

Engine Electrical System
The electrical system has three separate circuits.
the charging circuit
the starting circuit
the 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.
the battery
the circuit breaker
the ammeter
the cables
the 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.
Alternators
4N-3986 Alternator 4N-3987 Alternator
Illustration 1 g00530109
(1) Rectifier. (2) Rotor assembly. (3) Stator winding. (4) Coil and support assembly. (5) Ball bearing. (6) Regulator. (7) Roller bearing. (8) Fan.The alternator is driven by the crankshaft pulley through a belt that is a Poly-vee type. This alternator is a three-phase self-rectifying charging unit. The regulator is part of the alternator.This alternator design has no need for slip rings or for brushes. The only part of this alternator that moves is the rotor assembly. All of the conductors that carry current are stationary. The following components are the conductors: the field winding, the stator windings, six rectifying diodes and the regulator circuit.The rotor assembly contains many magnetic poles. These magnetic poles look like fingers with air space between each of the opposite poles. The poles have residual magnetism that is similar to permanent magnets. Permanent magnets produce a small amount of magnetic lines of force (magnetic field) 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.Regulators
3T-6354 Regulator 7T-5665 Regulator
Illustration 2 g00360155
Regulator assemblyThe voltage regulator