Re: Bridgeport motor question

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Robin Szemeti <list@r...>
wrote:

> On Saturday 03 January 2004 10:23, rivet3man wrote:
> > I'm preparing a series1 (BOSS) Bridgeport to fit PC-based

controls.

> > The main spindle motor is a US motors 2hp, & though the rating

plate

> > gives a connection diagrams (9 wire) for 220 and 415 volts there

are

> > actually just the 3 wires coming from the coils and I believe it

was

> > set for high voltage. I want to run it from 240Volts via an

invertor.

>
> So .. this motor has a 220V layout connection available? .. then

you
are home

> and dry, Just select the 220V diagram as per the manufacturers
> instructions and thats it
>

No, you missed the vital line above 'there are actually just the 3
wires coming from the coils'

> > I'm going to see if I can unearth the actual winding terminations,
> > but
> > if I get too far out of my depth it'll be off to the rewind shop

on

> > Monday for them to do it.
> > My question is, as understand it the US style 9-wire dual voltage
> > motor is star connected for both voltages.
>
> Probably, but who cares .. it has a 220V tapping and that will be

close

> enough ... use that. it doesnt matter whether its star, delta or

bavarian

> beaver cheese, its the right voltage, thats all you need to know.
>
> > More usual here in the UK
> > is 6 wire, with star connection for high volts & delta for low.

If
it

> > looks easier to reconnect this motor for delta than to unearth all
> > the
> > terminations to parallel the windings, will that be just as good?
>
> I'm not sure what you mean .. the whole idea is to end up with a

220V rated

> motor, one way or another. as the motor has a diagram of how to do

that, then

> you are home and dry .. no?
>
> (Officially the UK went 220V like the rest of europe some years

ago,
but the

> tolerance on the supply is so large, its still roughtly 240V anyway

.. but

> officially, its a 220V supply we have here in the UK)
>

The point was, as the terminations described on the rating plate
aren't available, will connecting a 9-wire motor in 'series delta' be
just as good as 'parallel star'. If it is, why has the US practice of
9-wire motors arisen (just out of curiosity?)?

I thought UK mains was now officially 230V, although in name only,
little has really changed. Here it usually measures around 240/242
Volts.

Thanks
Tim