Re: [CAD_CAM_EDM_DRO] OT Electric Motor Question

tcsibor@... wrote:

> Sorry for being a bit off topic, but I know that the knowledge on
> this group can help. I have a machine with a 3 phase 440 VAC motor.
>
> This motor (Bosch) has 6 leads and the wiring plate indicates that it
> can be wired star (Y) or Delta. The plate also says that it is "440 Y
> (star)"
>
> Does this mean that if it were wired delta, it would operate on 220
> VAC? If not, then why would one set it up for Delta over Star or vice
> versa?

With 440 V L-L in the Wye configuration, the windings have 253 V
across them. If you changed the motor to Delta, you'd need to provide
the same voltage across the coils, which are now wired L-L.

This will probably work pretty well on US 220 V service, which tends to
run quite high, and really is close to 250 V in a lot of places.

You have to be real careful in rewiring the terminals unless you have
a diagram to go from. You want to break the floating center tap wires
apart, and connect each to one of the line terminals going around in
the same direction. You can find which center terminal is connected
to a line terminal with an ohmmeter.

Jon