On Thu, 27 Nov 2008 01:15:01 -0600, Kevin wrote:

I just finished wiring in two 220V circuits to the shop -- 1 for the
dust collector (5.5A), and the other for the tablesaw (14.5A), jointer
(6.5A), and tbd.

Just for grins I put all of them onto the one circuit. So 5.5+14.5+6.5
= 26.5A. The 20A breaker did not trip. I even tried starting up the
tablesaw while the others were running.

Now in practice, I will keep my dust collector (5.5A, 1.5HP) on it's own
circuit, but apparently I could concurrently run both the tablesaw
(14.5A) and the jointer (6.5A) and possibly even a 3rd TBD on that other
circuit. How is that? The real load must be under 20A, or the 20A
breaker allows more like 28A.

I first tried the TS and Jointer, and when they did not trip the breaker
(total 21A), I added the DC. I was surprised all three did not trip the
breaker. But I guess each was running with no load, so that is surely
another reason.

Curious,

Kevin:

I honestly think you know the answer to this one:
The amperage rating is supposed to be the maximum current draw when
operating under normal working conditions. That means when cutting wood.

Most of the posters to this newsgroup only run one such power tools at a
time (they ain't a factory) so there is no problem with multiple power
tools on a single circuit.

Get a friend to help out. You rip cut some 8/4 rock maple on the TS and
let your friend do a 4 inch wide board face cut on the jointer (at the
same time of course.) Circuit breaker will trip. (But why would you do
this test in real life is way beyond my coffee starved brain's
comprehension.)