Circuit breakers are of two types "thermal" or "magnetic" so in theory a
magnetic breaker will act on current load rather than heat. I *think* the
breaker TT used for over load was magnetic which would be the best thing
for mobile, better than fuses as they too are changed by temp. Even
worse is a fuse during winter when they are cold the blow limit really
changes. The ideal setup would be a fuse slightly larger than needed by
the rig placed at the battery and the magnetic breaker in by the rig. If
you were using a thermal breaker like is used in buildings your right it
would not hold at the temps under the hood they are designed for a
different application. Another thing to remember is circuit breakers
should be sized using the proper power factor by design of what ever
breaker it is, to save from trying to figure all this out it's best to
find the proper one recomended by TT. The newer TT rigs have a very nice
current limiting circuit in them so the magnetic breaker is not really
needed but I think still a good idea if you have one. Now everyone get
those mobiles hooked up, don't leave home without your Ten Tec!
73 aa8ve -Jeff-
On Fri, 15 Oct 1999 10:24:01 -0500 "George T. Baker" <w5yr@swbell.net>
writes:
>
> Carl, let me add one personal observation re circuit breakers vs
> fuses in
> a mobile installation.
>
> Once I installed a 100-watt transceiver - an Icom 730 - in a car and
> ran
> the power leads directly to both terminals of the car battery. I
> then
> placed a circuit breaker - industrial grade, etc. - in the cable
> near the
> battery.
>
> This worked fine except that on hot days the temperature under the
> hood
> would rise to the point that the breaker would trip on ambient
> temperature, not a current overload. Nothing dangerous - it just
> shut
> down the radio when nothing was wrong.
>
> This experience convinced me that a breaker needs to be rated for a
> high
> ambient if it is to be located under the hood. Lacking that, a fuse
> might
> be the next best thing.
>
> 72/73, George AMA 98452 R/C since
> 1964
> Amateur Radio W5YR, in the 54th year and it just keeps getting
> better!
> AutoPOWER Systems, Fairview, TX (30 mi NE Dallas) Collin County
> QRP-L QRP-ARCI FISTS NORCAL ZOMBIE ARS 10-X 33.2 N 96.6 W EM13RE
>
>
> Carl Hyde wrote:
>
> > When running any radio mobile a circuit breaker is a
> > must. Fuses don't always offer complete protection and
> > if you really wanted to do it right then a circuit
> > breaker on the positive wire and one on the negative
> > wire is the way to go.
>
> --
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