Re: [CAD_CAM_EDM_DRO] DC motor - Controlled over-current - how much??

The Temp Rise is a design rating, usually based upon
operating in ambient air temp of 40 deg C., with the motor
running at continuous rated load. So, 25 deg plus 40 deg is
65 deg C. = 149 F. That's how hot the wires inside the
motor may get from running continuously at 100% rated load.
Is it 'open-construction, drip-proof, enclosed, TEFC, or
what? If it is fan-cooled, I don't think a 2 minute
exposure of 160% would cause appreciable harm, if you've
not been running at full 100% for a few minutes beforehand.
What Class is the insulation? Class A should allow 40 deg
C rise over 40 deg C (a total of 176 deg F), (ouch, you'll
burn your hands)! Class B should allow up to 230 deg F,
total. But, I don't think I'd try 300%, unless the motor
windings have a thermal cut-out.

RayHex


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> From: onecooltoolfool <joevicar3@...>
>

SNIP

>
> How much can I go over the rated 4.5 amps and for how

long?

> There is a "Temp rise" rating on the motor plate of 25C.
> What does this mean and can I use it to estimate my

overload capacity?

>
> Thanks
> Joe V.