Hello Troy
Under no circumstances should you use the AC (alternating current) rating
for a circuit breaker in a DC (direct current) electrical system. The reason
for this is that the alternating current reduces to zero twice per cycle (ie
100 or 120 times the second, so that any arc that forms as the contacts
separate will be extinguished within a few milliseconds. This allows the
breaker to break a much larger current, and do this repeatedly before the
contacts are damaged. The same value of direct current may continue to arc
across the contacts if they are not designed to to handle it -- at worst,
the contacts may fuse together and at best the breaker will have a short
life in terms of the number of trips before it fails.
Unless you know for certain the DC rating of a contactor or circuit breaker,
do not assume that an AC breaker will handle any useful level of DC load,
however large its AC rating.
Brian Rauchfuss's advice is sound -- rate the fuse or breaker to protect the
wiring.
I assume that "starter" refers to the starter relay: the starter itself
should be connected by the shortest route of heavy duty cable with no fuse
or breaker.
Fly safely
Mike
Europa Club Safety Officer
-----Original Message-----
From: TroyMaynor@aol.com
Subject: Alternator Breaker
Hi Again,
I have notice some have used an a.c. breaker on the panel instead of the
30 amp slow blow fuse inder the cowl. I have a 35 amp a.c. breaker that I
bought at the swap meet at Sun n Fun a few years ago. The following
information is printed on the side. 35A a.c. S-1360-35 MP-1600Y-35
Mechanical Products
Is this an aircraft breaker or for industrial or either? Does anyone
have any idea if this is ok to use for the alternator?
Thanks,
Troy
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