Dave Osborne wrote:
John Rumm wrote:

Does anyone know if there is a way to assess the typical inrush
current for an induction motor?

I helped a mate install a new motor in a small saw table the other
day. The motor he had to hand was a monster 3kW jobbie that had been
bought for some other purpose but never used. I suggested this might
be overkill for the application, since we are only talking about a 7"
blade here!.

Anyway hooked it up via a DOL starter and set the max current trip on
it to something sustainable on a 13A plug. (the motors full load draw
being 17A IIRC). Not unsurprisingly we could only spin it up on a
circuit protected by a 32A type B MCB - any circuits off 16A MCBs
tripped immediately. Load when running (but not cutting) was 7A (could
not try any cuts since we did not have a suitable belt and pulley).



Have a look he http://www.memonline.com/cb11.html

The figures they give for 3 ph seem ok, but I am not sure about the
single phase ones - the MCB ratings suggested seem excessive, especially
for type C devices.

--
Cheers,

John.

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