Re: Fuse for an AC motor

On Feb 4, 12:02 am, "Uriah" <uriah...@xxxxxxxxxxx> wrote:
On Feb 1, 1:37 am, "Homer J Simpson" <nob...@xxxxxxxxxxx> wrote:

"Uriah" <uriah...@xxxxxxxxxxx> wrote in message

news:1170241636.521519.289640@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Ok, so the bottom line is no a fuse won't work? But it looks like I
have a number of good ideas. Thank you to all. I will start checking
into all of them. They all sound very workable.

You CAN protect them but a regular fuse is unlikely to help. What sort of
HP/amps are they?

Here is what I found out. When I wire them up the draw .37 amps.
This is with them not being installed in the machine. When I stop the
motor with a pair of vise-grips it draws .49 amps. So I have about .
10 of an amp to deal with. But if I put them in the machine the are
probably going to drag it down a little. So that might cut my margin
to less then .10 amps. Maybe .07 Amps. I think that this is too
little of a difference to be able to catch with a fuse? I would have
to find a really acurate fuse that blows at exactly .45 amps. I think
it will have to be a Rockwell CB fuse but will it work with something
with this small of a margin? As far as the thermal I guess I will
have to let the motor run in the machine check the temp and then add 5
degrees? Is that the right idea?

Hi, Uriah. It does sound tough. For very small AC motors, this can
be a difficult problem to solve with either a fuse or a circuit
breaker. Have you considered a mechanical aid like a breakaway
clutch? In the event of excessive torque, the cluch disengages from
the load, saving the motor.

Cheers
Chris

.

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