On Tue, 14 Nov 2017 21:33:21 -0500, wrote:

On Tue, 14 Nov 2017 01:12:22 -0500, Clare Snyder
wrote:

On Mon, 13 Nov 2017 20:59:05 -0500, wrote:

On Mon, 13 Nov 2017 15:09:25 -0600, dpb wrote:

On 13-Nov-17 12:06 PM, wrote:
...

Sure, but why is that wire less susceptible to a short than a wire not
feeding a motor? If the OCD is there to protect the wire, it doesn't
matter what fails on the other end of it.

It isn't, but a short is by definition a high-current event so the size
of the breaker is essentially immaterial.

That's not my point. Forget the motor operation. What happens when
it, or the outlet itself, shorts?

The amperage rating of the breaker protects against continuous
overcurrent; the motor is different in that the high current only lasts
for a few msec at most; the current draw is well within the ampacity of
the wire otherwise.

Again, not the point. OCDs are there to protect the wiring during a
failure. Motors, or devices with motors never fail?



The SHORT circuit protection is still there. short is an
instantaneous very high current spike that will still trip the breaker
IMMEDIATELY

But that is *not* why the OCD is there. Are you saying that motors
can never fail?


No, I'm saying motors have built-in thermal protection, and a "motor
failure" will increase current by 5 amps pretty darn quick - so the
circuit breaker will still protect the wire. I wouldn't go stupid and
install a 30 (or heaven forbid a 40) amp breaker.

I'm pretty sure the high-mag breaker will do the job anyway, given
the symptoms and amp draw readings I'm getting.