Re: Stepper Motor (was: Harrison Lathe and Gecko's)

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:

Jon,

All the specifications I have seen for motor rated enamelled copper
wire show a dielectric constant of over 2KV. I am not aware that any
motor manufacturer buying in special low insulation wire for low
voltage motors.

A regular ohm meter with a 9volt battery can not detect insulation
breakdown, unless it is catastrophic in which case you can probably
smell it. Thats the whole reason for megger type instruments.

Bernard

>
>
> Bernard R wrote:
>
> >Terry,
> >
> >Testing with the megger will not harm the motor. Its purpose is to
> >see if there is a breakdown in the insulation at high voltage.
> >Readings coil/coil and coil to frame should be infinity, or very
high
> >(tens of megohms).
> >
> >
> Many meggers put 1500 VAC on the motor windings! This would be
expected
> to break
> down the insulation on a motor only rated to 65 V or so.
>
> Jon