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Josepi[_5_] Josepi[_5_] is offline
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Default Shop Wall and Electric

Never combine two motor loads on one circuit. The simultaneous starting
current will typically take out the breaker when you least want it to.

Two motors on any breaker / circuit is a big no-no and will also not protect
your equipment from any locked-rotor current. This is when the equipment
jams or shorts out and the circuit breaker is sized wrong for that piece of
equipment (big enough to carry the two motors), does not trip and your motor
windings go up in smoke. Bigger repair bill and possible fire hazard.

Proper motor protection circuits found in industry typically have two levels
of protection, one for the large starting current and one for the typical
loaded running current. Anything lasting longer than the two situations, at
that current level, will trip out the breaker / circuit interupter.

In home usage only one level of current protection is typically afforded
with a simple breaker. Don't defeat it by combining two motor devices. The
Electrical Inspector would advise against you doing this, if he catches it
or you ask.



"dpb" wrote in message
...
Bill wrote:
The last is just silly...

I'd (more or less) agree w/ the other posters...

Agree on separating the 120V on own circuits and moving up to 30A/10ga
over 20A/12ga for at least a couple of the circuits (and if do any,
might as well do all).

Slight disagreement w/ at least one suggestion...30A @240V is enough for
any reasonably efficient 5-horse single-phase motor and given that going
to 30A outlets raises compatibility and cost significantly, I don't see
any need/justification for more than that for anything other than a
dedicated welder circuit or somesuch. Presuming, of course, that the
distances are reasonable so that voltage drops are 5% or less and this
is a typical home shop, not commercial or a behemoth thing...

Agree that the "never enough" for 120V and the overhead are certainly
also truisms as well as the admonition for lights to not be on work outlets.

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