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Originally submitted by T:

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Note the toothed Fan Belt for increased purchase on this 12 Volt Generator. Large Alternators can benefit from the use of one of these. Click to Enlargen. Photo by Sherro.


===Generator Operation:===A generator consists of a stationary electromagnet (called the field) and a rotating set of coils (called the armature). The armature forms part of the generator's centre shaft.

Grey 132 cu in Holden Six Cylinder Engine. The red box is the Regulator. The car is fitted with a Generator. Click to enlargen. Photo by ReaperHR.

===Voltage Regulator:===The Voltage Regulator controls the current entering the field. The more current that the Regulator allows into the field the more power the generator delivers. It works in exactly the same way as the voltage regulator for an Alternator.

===Current Regulator:===

Lucas current, voltage regulator and cutout relay as fitted to EH and earlier Holdens. Click to enlargen. Photo by hztonner308.

Generators are capable of producing far more current than they are rated for, and in doing so will exceed the current rating of the armature windings and can burn themselves out. Therefore, they must have the protection of a current regulator. The Current Regulator introduces a resistance into the field circuit whenever current peaks appear thus limiting the amount of power the Generator produces. ===Cut-Out Relay:===

The Cut-Out Relay detects any current that tries to run back into the Generator's positive terminal. This happens when the generator is turning too slowly to generate sufficient Voltage to match the Battery Voltage. Should any reverse flow of current occur, the Cut-Out Relay contacts open and prevent that current from flowing by disconnecting the Generator from the Battery.

==Generator Installation:==

===Belt Alignment:===

Make sure the generator pulley is in perfect alignment with the harmonic balancer (the crankshaft pulley). If not the harmonic balancer will flex and cause a vibration as the engine revs up. Flex of the harmonic balancer will eventually cause the destruction of the balancer. ===Fan Belt Tension:===

Fan belts shrink when they get hot so it's best to check or make any adjustments to the fan belt tension when the engine is hot otherwise excessive tension will be placed on the bearings resulting in a failed generator and/or broken fan belt when the fan belt heats up. ==Generator Tips:==


The brushes in a generator will eventually wear out. Provided that the commutator (the copper device they come in contact with) does not have excessive wear, the brushes can be replaced. Full output of the Generator will not occur until the brushes have made 100% contact with the commutator. That means the brushes must have the same contour as the commutator. Some people touch the commutator with com-stone (a stick of abrasive material that will cause the brushes to bed in faster) others prefer to use comm-emery paper (emery paper which has glue on the other side) which will lightly sand the brushes to match the commutator's contour.

===Protection from entering Contaminants:===

If performing any work on the cooling system, cover the generator with a cloth. Any coolant that gets inside the generator will cause an internal short of the field or armature windings.


Many generators have a ball bearing at one end and a sintered bronze bearing at the other. While replacement of the ball bearing can be relatively easy, the armature shaft may be too worn to permit replacement of the sintered bearing.

== Generator Excitation:==

===A Generator That Has Been Self Excited:===

A self excited generator can reverse its polarity if the unit is dropped, hit or bumped in any way. A self excited generator should have its output checked to ensure it has not reversed its polarity.

Generator Polarity

===A Generator That Has Been Excited by a Battery:===

A battery excited generator, one that is in the car, will automatically come up with the correct polarity because the generator light will "flash" the generator's "field" into the correct magnetic sense.

==Generator Wiring:==

Submitted by FJDave on Thu, 29/03/2007 - 07:37. FC Generator: Assuming wiring is original... Dark Blue wire to F (field) Brown wire to D (dynamo) the other connection goes to an earth The F wire goes directly to F on your regulator The D wire directly to D on your regulator - the other wire coming into the D terminal on your reg comes from your GEN light on the dash Hope that helps Dave


Generator on a 138 EJ Holden Six. Click to enlargen. Photo by Ishjana Elsher.



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