[VAC] Re: Charge line fuses

["Weimers" <mweimer@xxxxxxxx>]

I was using a fuse at first, but when it blew on two separate occasions, I
was not aware that my trailer battery was not charging until the lights went
dim. (my ammeter doesn't work because of the missing shunt and the Univolt
conversion).  I decided to use a circuit breaker instead of the fuse. Since
the automotive circuit breakers are self-resetting, the charging line will
keep working even after a high load trips it. I suppose that the fuse would
be safer in the event of a dead short.  I'm not an electrical engineer, so I
don't have the figures of what loads a particular gauge of wire should
handle, so I'm glad to see you recommend a 30 amp fuse. I was using a 50 amp
fuse , I
think, which I suspected was too large ....and you confirm that.  But
...what are your thoughts about using the circuit breaker as opposed to a
fuse?   Should the circuit breaker be rated lower than a fuse (since it
takes more time to "trip" it)? Maybe it would also be good to use a fusible
link in the charging line in conjunction with the circuit breaker?
What's the best way of hooking these things up?

Originally, I also used a (separate) fuse on my trailer brake line also. I
decided that was really unsafe and switched to a circuit breaker ...since
they reset themselves.

On an aside:  never install an automotive circuit breaker upside down so
that the case can collect water. I had one short out when my heater hose
exploded and filled the circuit breaker with antifreeze! (Often, I learn the
hard way.)

MARC WEIMER
Punxsutawney, PA  -  Home of the Groundhog
#15767
1963 Globe Trotter
1971 Globe Trotter
http://users.penn.com/~mweimer/weimer.html