C-172 landing light switch

At low RPM the cut out relay in the regulator is SUPPOSED to open so
that the battery does not BACKFEED into the generator. This is relay
is apparently not opening. This relay has two windings, one of many
turns of fine wire and the other is a few turns of heavy wire. When
the generator is charging the two windings add to keep the relay
closed. When the generator RPM is low the battery back feeds the
generator and tries to run it as a motor. When this happens the
fields of the two windings oppose each other and the armature contact
to the battery opens. Since the circuit breaker has opened so many
times it most likely will not hold rated current either.

REPLACE THE VOLTAGE REGULATOR AND THE CIRCUIT BREAKER.

JF

On 03 May 2004 23:04:47 GMT, (JFLEISC) wrote:

but your generator is capable
of delivering only 30A, then the genny should be up to delivering its
full rated 30A output all day long. It shouldn't care what the total bus
load is... (turning on extra load should not trip the genny breaker)

No argument here. But lets say that the FULL rating is 30A. What is the output
if it is spinning at %10 of that full rated speed? How much current will now be
going over those oxidized breaker contacts that seemed to handle the full speed
output current OK?

Jim