LUCAS Alternators: Description

NOTE: Some Jaguar models may be equipped with Motorola alternators. See appropriate article in this section.

Lucas ACR model alternators have an integral, non-adjustable voltage regulator, mounted in the slip ring end bracket. Individual connectors are used to connect external wiring to the alternator.

The rotor, which turns inside the stator, has its field windings connected to 2 face-type slip rings. It is supported in the drive-end bracket by ball bearings and in the end cover by needle roller bearings.

One positive and 1 negative carbon brush ride against concentric brass slip rings. The heat sink, rectifier, and terminal block assembly incorporates 6 silicon diodes, forming a full-wave rectifier bridge circuit, and 3 diodes which supply current to the rotor windings.

Individual diodes cannot be removed from the heat sink assemblies. A surge protection diode, in the outer face of the slip ring end bracket, protects the diode pack from high transient voltages resulting from faulty cable connections.

NOTE: Precautions should be taken while attaching and detaching cables, as surge protection is limited. Observe polarity and never connect or disconnect wires while engine is running.

APPLICATION

Model		Type No.
XJ6
	With Air Conditioning	25 ACR
	Without Air Conditioning	18 ACR
XJS		25 ACR

Fig 1: Exploded View of Lucas 25 ACR Alternator with Integral Regulator

Courtesy of NOT AVAILABLE

SPECIFICATIONS

	Nominal Output
Alternator	Amps@6000 RPM	Voltage
18 ACR	45	14
25 ACR	66	14