UncleWillie
Captain
- Joined
- Oct 18, 2011
- Messages
- 3,995
Re: Fuse For Battery Cable Protection
Yes! You have a very nicely installed 200 amp breaker in the battery cable that gives you a Sense of Security and no problems. (And I honestly mean that in the nicest way.)
But it misses the point.
A 90HP motor initially draw a few hundred amps (~500?) for a few milliseconds while the starter comes up to speed and then draws less than 200 amps while cranking normally. The breaker does not trip.
Your cables (4awg?) are continuously rated for 70 amp at 60?C (140?F), with a MAX Rating of 95 AMPS at 90?C (194?F) if you purchased it with high temperature insulation.
In either case, if the circuit were ever to draw 190 amps for any period of time, the wire would go up in smoke and the breaker would not trip. The breaker is there, but it is not protecting the wire! :blue:
Yes! You have a very nicely installed 200 amp breaker in the battery cable that gives you a Sense of Security and no problems. (And I honestly mean that in the nicest way.)
But it misses the point.A 90HP motor initially draw a few hundred amps (~500?) for a few milliseconds while the starter comes up to speed and then draws less than 200 amps while cranking normally. The breaker does not trip.
Your cables (4awg?) are continuously rated for 70 amp at 60?C (140?F), with a MAX Rating of 95 AMPS at 90?C (194?F) if you purchased it with high temperature insulation.
In either case, if the circuit were ever to draw 190 amps for any period of time, the wire would go up in smoke and the breaker would not trip. The breaker is there, but it is not protecting the wire! :blue:
