Jim Stewart wrote:

Because my motor has two sets of windings..a high speed and a low speed
set. Not been reading?

I don't believe there is such a thing as a high and low
speed set of windings. I think they are all used for
both speeds, but rearranged to double or halve the effective
number of poles in the motor.



If it is like most CNC's with 'electronic' gearing, you have the connections to configure
the motor as delta or wye. That is how they get the high and low.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller

On Mon, 04 Jan 2010 19:19:42 -0500, Wes wrote:

SNIP
If it is like most CNC's with 'electronic' gearing, you have the connections to configure
the motor as delta or wye. That is how they get the high and low.

Wes

Hey Wes,

Ummmm....not really. I'm assuming that the discussion here is about
squirrel-cage types. A 2-speed motor is just that. And star-delta
is a method of limiting start-up currents, or rather, reducing
run-speed current, and is not a "speed changing" scheme. The motor
wants to run at its synchronous speed. Many motors run star only, or
delta only, depending on the application. The field windings are the
same for either one.

2-speed on the other hand is just that, using two different sets of
field windings, commonly to provide a 4:1 ratio. For most I've seen
the available torque is reduced on the slower speed, unless it is a
"special purpose" type.

Lots of 2-speed motors are wound-rotor, and therefore can be used as
universal. These can have variable speed, rather than just 2-speed,
but often are set up to operate as just 2-speed.

Take care. Happy New Year.

Brian Lawson,
Bothwell, Ontario.

Brian Lawson wrote:

On Mon, 04 Jan 2010 19:19:42 -0500, Wes wrote:

SNIP
If it is like most CNC's with 'electronic' gearing, you have the connections to configure
the motor as delta or wye. That is how they get the high and low.

Wes

Hey Wes,

Ummmm....not really. I'm assuming that the discussion here is about
squirrel-cage types. A 2-speed motor is just that. And star-delta
is a method of limiting start-up currents, or rather, reducing
run-speed current, and is not a "speed changing" scheme. The motor
wants to run at its synchronous speed. Many motors run star only, or
delta only, depending on the application. The field windings are the
same for either one.

[snip]

http://www.cncmagazine.com/archive01/v2i07/v2i07i.htm

Damn. You are right thanks for clearing that misconception from my mind.

Thanks,

Wes

Right on, Brian ! Some 2-speed induction motors are classed as "constant torque"; others are
classed "constant horsepower". All of them utilize stator windings in which the number of poles is
changed, usually 2 pole and 4 pole. Star-delta and delta-star configurations account for the
constant HP and/or constant torque designs.

Bob Swinney
"Brian Lawson" wrote in message
...
On Mon, 04 Jan 2010 19:19:42 -0500, Wes wrote:

SNIP
If it is like most CNC's with 'electronic' gearing, you have the connections to configure
the motor as delta or wye. That is how they get the high and low.

Wes

Hey Wes,

Ummmm....not really. I'm assuming that the discussion here is about
squirrel-cage types. A 2-speed motor is just that. And star-delta
is a method of limiting start-up currents, or rather, reducing
run-speed current, and is not a "speed changing" scheme. The motor
wants to run at its synchronous speed. Many motors run star only, or
delta only, depending on the application. The field windings are the
same for either one.

2-speed on the other hand is just that, using two different sets of
field windings, commonly to provide a 4:1 ratio. For most I've seen
the available torque is reduced on the slower speed, unless it is a
"special purpose" type.

Lots of 2-speed motors are wound-rotor, and therefore can be used as
universal. These can have variable speed, rather than just 2-speed,
but often are set up to operate as just 2-speed.

Take care. Happy New Year.

Brian Lawson,
Bothwell, Ontario.

Brian Lawson wrote:

Take care. Happy New Year.

Brian Lawson,
Bothwell, Ontario.


How was Vegas? Did you see Hoover Dam?

Wes

On Tue, 05 Jan 2010 19:48:20 -0500, Wes wrote:

Brian Lawson wrote:

Take care. Happy New Year.

Brian Lawson,
Bothwell, Ontario.


How was Vegas? Did you see Hoover Dam?

Wes


Hey Wes,

Thanks for asking. We did go to see the Hoover Dam, in fact on
Christmas Day!! And while there were no tours available due to the
Holiday, there was a lotta lotta lotta people doing what we were doing
too !!! I have been at THE Dam a couple of times before, but my new
daughter-in-law had not and she was amazed, mostly at the sheer drop
on the "dry" side, although at present it's a bit hard to tell which
"side" that is due to the Lake Mead water levels at the dam and as far
as you can see being about 150 feet below "normal". And WOWWWW!!!
that's a LOTTA water, or not water in this case.

I was most interested to see the completed new bridge, only to find it
more interesting in that it is not complete yet, and so the means and
methods of construction are readily visible, albeit from about 1/4
mile distant. Ummmm...that's not quite true, in that the "old road"
to the west side of THE Dam allllmmmmmooooossstttt does a tight U-turn
right under one span of the new bridge. One thing for sure, it will
certainly speed up the "thru" traffic in the area, as now there is a
"9/11" security inspection on the approaches that slows down traffic
as much as the "gawkers" do on the very winding existing road.

Vegas was a Christmas Present for the kids, so Dad here was picking up
the whole shot except the one-arm (now button pusher) bandits. 4 bucks
for a coffee in Vegas was a bit much. So I was paying over 45 bucks
for breakfasts and minimum $150 plus tip for dinners for the 4 of us.
That's OK on a one time, but 5 days worth is getting expensive for
this old retiree. I've got better things to spend my money on!! Lotsa
things that were complimentary the last time we were there are now a
profit maker, as the Vegas 2008 income was down 12% over 2007, and
2009 probably wasn't much better. And you can't walk down "the strip"
at any time that some greasy looking group isn't handing out call-girl
cards, most of which end up on the sidewalks. The city should charge
them for clean-ups!! And we had expected to take in a few "shows",
but the prices are as Steve B. suggested in his pre-Xmas email advice.
Seemed to run about $ 130 per head, and I balked at that and we didn't
see any. And long line-ups for almost everything, and my knees are
pretty good, but not that pretty good to stand in any line for an hour
or more.

We had nice rooms at Bally's though. That I would recommend to anyone
going. Ask for a room with a "Strip view".

So, if it was the first time I had been there, I would say "I've been
to Vegas twice. The first time, and the last time!!" No plans to go
again. Maybe do Carlsbad next time.

Take care. Happy New YEar.

Brian Lawson,
Bothwell, Ontario.