Generator Tips
GENERATOR POLARITY
A generator from a positive earth
car can be used on a negative earth car (vise-versa). It will be necessary, however, to
polarise the generator. To do this, mount the generator on the car and connect all
wires including those from the cut-out relay. When all connections have been made,
and before the motor is started, simply press the cut-out relay points closed for about
one second, then release. Be careful, though, some cut-out relays tend to lockup, so
it may be necessary to force its release or disconnect the battery. Don't leave the
cut-out operated with the engine stationary as this could cause the generator windings to
burn out.
N.B. This method of polarising is not applicable to alternators, which use diodes for
rectification and are therefore polarity discrete.
GENERATOR AND STARTER MOTOR COMMUTATORS
Commutators should be cleaned with fine glasspaper only, do NOT use emery paper. If the commutator needs to be trued, spin or lathe
at high speed and cut with a sharp tool. Remove only a small amount as is necessary.
After truing a generator commutator, the insulation between the segments should be
undercut to a depth of about 1mm. (a broken hacksaw blade, ground to the necessary
thickness, is ideal for this purpose.) The commutator of a starter motor should
generally NOT be undercut. The insulation should be left level with the commutator
faces.
Copyright © 1998 Morris Register of Victoria. All rights reserved.