On 14-Nov-17 8:32 PM, firstname.lastname@example.org wrote:
Precisely _because_ it is a motor circuit and motors are different and
NEC understands that.
It's all in Section 430 but short story is as outlined above; ampacity
of the wire is determined for FLA of the motor; the breaker/fusing is
sized to allow to be able to handle inrush starting current and the LRA
or similar _continuous_ overcurrent protection is _NOT_ provided by the
breaker but the _REQUIRED_ thermal protection for the motor (and thereby
the wiring as well).
IOW, there's a second layer of protection besides the branch circuit
breaker of a "normal" branch circuit you're used to that isn't in the
lighting/general use circuit which relies on the one device for both
And, if the thermal protection is built into/comes with the motor,
that's allowable; larger motors of the woodworking-shop class generally
have "heaters" located in the starter enclosure that can be simply
inline fusible links that serve the purpose or the "thermal reset"
button in a motor that is just a circuit breaker or there are similar
resettable heaters as well.
Doesn't matter _where_ the device is, specifically, but must be there by
On Tue, 14 Nov 2017 21:33:21 -0500, email@example.com wrote:
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.
Correct - but replacing the original breaker with a brand new
identical breaker did not help - and thermal tripping degrades a
breaker significantly more than magnetic tripping - which does not
cause any appreciable heating in the breaker.
Magnetic tripoping is instantanious tripping - thermal tripping is
delayed. (due to prolonged overload)
I had to put a high-trip mag breaker on one circuit which was serving my
shop dust collector. Around here it was a matter of going to the nearest
big-box store -- both Lowe's and Home Depot had them available -- and this
is in a decidedly less populated area than Ontario.
Home Despot Canada doesn't carry them at all. Nor does Lowes Canada.
Rona Canada used to carry them, Rona was recently absorbed by Lowes.
Home Despot in the USA apparently DOES carry them but both Buffalo and
Detroit are about 3 hours away.
In Quebec Reno Depot carries the high magnetic breakers in their
stores. That's well over a 5 hour drive.
Sounds like the sort of crap that we had to put up with living in Alaska
except that sometimes it was a 3-hour flight rather than a 3-hour drive.
Your situation seems so odd -- these are scarcely some sort of rarely-used
magical devices and many applications really do need them all the time.
A lot of the problem here is American companies who see Canada as too
small a market to bother complying with our bi-lingual labelling
requirements. No french labels means no sale in Canada. I think youcan
sell in Quebec with french only labelling - which may be why SOME
things are avaiable in quebec only - the quebec based outlet doing
their own labeling?
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.