On Mar 9, 7:58*pm, Tom Veatch wrote:
On Mon, 9 Mar 2009 13:39:57 -0700 (PDT), jtpryan
wrote:

So, that being said, how dangerous is it if I have the 30 in
there, fire up the TS and DC for all of maybe 3 min at a time at the
absolute max, probably less, and that's it.

It may not be dangerous at all. The wire ampacity is based on the
temperature rise in the wire at a given current level and the maximum
temperature the insulation can withstand without damage. It could be
that for brief periods of usage and enough down time to allow the
wires to cool, you'd never exceed the temperature limits of the
wiring. But that's a pretty big if.

If you decide to go that way, and the danger isn't trivial, when the
fire department completes its investigation and finds a 30amp breaker
feeding 12 ga wire, expect the company that wrote your homeowners
insurance to refuse to pay the claim.

Incidentally, if the circuit is properly sized for the full load
amperage of the motors on the circuit, the starting inrush will not
trip a properly functioning breaker. You don't need to size the
breakers for the inrush, only the full load running amperage. If you
want to size for inrush, look at the motor dataplate and multiply the
amperage shown by about 5. Your 13 amp DC would need a breaker that
supported over 60 amps.

Tom Veatch
Wichita, KS
USA

Well, you guys put the fear of God (and the insurance company) in me.
No 30 Amp breaker. I will look for the "slo-blo" though. What I
don't get is how this product ever works, at least with table saws. I
think I have a prettty standard setup for the market they are trying
to reach.

I'll see how the breaker change goes...

-Jim