john61ct said:
The higher voltage is not a problem.
Using higher voltage than a breaker or fuse is rated for *is* a problem.
Or at least, could be.
Breakers and fuses have a voltage rating because they can only be guaranteed to break the arc of a voltage below that of their maximum rating.
If the arc doesn't break, then not only is the circuit not broken, and current continue to flow anyway, but the breaker (or fuse) is now filled with a plasma arc, like a welder, and is now heating up very rapidly, with significant potential for fire. Whether a fire happens there or not, the circuit is not broken so whatever caused the overload is still happening, and if *that* is a short circuit, then that will keep being fed current and continue to heat up, and *that* could lead to a fire, too. At the least, it can't protect whatever it's there to protect.
Now, it doesn't mean it wont' work, just that it isn't guaranteed to, so you should not depend on it working, and should also use something that is properly rated for the system.
So...while I have a breaker on the trike that isn't rated at the voltage I'm using it at, I *also* have a fuse on the pack's main lead, just in case. The breaker isn't actually there even to protect the system, it's really there as a master switch, anyway. But if it helps as a breaker, too, that's ok.
SwampDonkey said:
True. I'd like to build a nice little N channel mosfet switch. I was thinking 3 IRLB3034s in series.
The problem is that FETs usually fail on, so if anything goes wrong with it, it will likely not break the circuit.
Also, why use three FETs in series? This complicates your gate drive circuitry, at best.
