On the MOTOR subject

Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.

Moderators: GlennW, Harold_V

Post Reply
Lew Hartswick
Posts: 775
Joined: Sat Jan 04, 2003 10:45 am
Location: Albuquerque NM

On the MOTOR subject

Post by Lew Hartswick »

Ran into something yesterday I never have before. This was to help a woodworker who just bought
a bunch of machinery (some of it BIG). A planer (wood type) ie. a surfacer, made in Italy.
In trying to come up with a power requirement for a VFD (mostly to get 3 ph from his single ph)
the main motor name plate showed a delta connection at 1750 rpm and a Y at 3450 rpm with only
6 terminals for the connections. two sets of 3, X,Y,Z and U,V,W . All at rated voltage of 220 .
Finally figured it out.
Does anyone want to play guessing games or should I give it away ? :-)
I'll have to draw up a sketch and post it to describe it right anyway.
Tomorrow or Sat I'll do it.
...Lew...
User avatar
refinery mike
Posts: 623
Joined: Sat Jul 02, 2011 1:54 pm

Re: On the MOTOR subject

Post by refinery mike »

the speed of a motor is determined by the number of poles in the winding (and the frequency) to get a motor that ran at both speeds would require separate windings on half the poles. two poles producing 3600 rpm and four poles producing 1800 rpms. What you probabaly have is a delta start wye run motor. Delta-Wye motor. They were used for starting heavy loads or starting less abruptly. I do not know if they still make them. they require special starters to opperate them. good luck i have not seen prints for hooking them up since i was a kid. and it was on German printing presses.
atomarc
Posts: 264
Joined: Sat Oct 03, 2009 7:13 pm
Location: Eureka, California

Re: On the MOTOR subject

Post by atomarc »

Lew,

Interesting thread. I worked on a friends double table shaper, which was an old Onsrud...made in the USA. This machine originally had a 9 lead, two speed motor. 1750 and 3600 RPM. The speed change was achieved with a very large drum switch that swapped motor leads.

I have worked on many European machines that had 'wye-delta' starting which was accomplished with two mags and a timer. Your motor leads are numbered in a IEC fashion but you are indicating that it's an actual two speed motor. I'm not a motor guru so I'm interested to see what kind of solution you share with us on this topic.

Wye-delta starting (soft start) is not to be confused with a two speed motor...I think! This method of starting reduced the current inrush of the motor and the subsequent power bill the customer would see...peak power!

Stuart
hammermill
Posts: 2938
Joined: Sun Jun 27, 2010 10:43 pm
Location: pendleton or

Re: On the MOTOR subject

Post by hammermill »

the germans love this on the sadelman chopper ( used to make sausage chopped ham etc) they would do wye,delta start and then stack the windings one way for mid speed and another for high speed

saw a awful lot of pork loin become sausage.

refinerymike i still see them coming out sometimes even with multi step start starts to get things up to rpm

in the past i also have seen 60 cycle motors turned a 2 or 3 times rpm to act as 120 or 240 cycle power sources. it would make the planer heads really scream on a woods or yates american planner
User avatar
Harold_V
Posts: 20231
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: On the MOTOR subject

Post by Harold_V »

atomarc wrote:Wye-delta starting (soft start) is not to be confused with a two speed motor...I think! This method of starting reduced the current inrush of the motor and the subsequent power bill the customer would see...peak power!
Not so much the power bill, as the same amount of energy would be expended, just spread out over a longer time interval. That prevents dimming the neighbor's lights.

I am on a demand meter. The load must be for 15 minutes or more before demand changes. That's a long time to get a motor started! :-)

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.
Lew Hartswick
Posts: 775
Joined: Sat Jan 04, 2003 10:45 am
Location: Albuquerque NM

Re: On the MOTOR subject

Post by Lew Hartswick »

Tomorrow. Got to re-scan the page and it's time to go to school . :-)
...lew...
hammermill
Posts: 2938
Joined: Sun Jun 27, 2010 10:43 pm
Location: pendleton or

Re: On the MOTOR subject

Post by hammermill »

ah demand meters. several customers in this area have large pumping stations etc. wow is to the man who fires up the pumps before the start of the season. i have seen huge bills just to start a motor to test it. 1 push of the button can be 3500 dallors.if done at the wrong time.

some meters read peak in blocks of time others use the peak to add a multipler factor to the bill for the peak demand. it varies greatly power company to power company my area has 7 different utilities for power within a 50 mile radius.
Lew Hartswick
Posts: 775
Joined: Sat Jan 04, 2003 10:45 am
Location: Albuquerque NM

Re: On the MOTOR subject

Post by Lew Hartswick »

OK I got the sketch scanned now to see if it posts.
First this is intended to be a two speed motor for the user to be able to switch between two
feed rates on the surfacer. Nothing to do with starting or all the other things mentioned.
It's strictly a 220 v 60 Hz motor and with a suitable switch (probably some form of a drum switch)
will just switch back and forth as required.

Along these lines I wonder about the use of the terms "4 pole" and "2 pole" as related to a 3 Phase
motor. But since it seems to be the accepted practice I guess I'll have to conform. :-)

The metal tag has the following info. (I don't have a photo)

220 v 60 Hz
4 Pole Delta; 1.1 KW ; 1.5 hp ; 4.9A ; 1750 rpm (it isn't rpm it's what ever the Italians use)
2 Pole Y ; 1.5 KW ; 2 hp ; 5.9A ; 3450 rpm

The connections are shown for the Lo speed (delta) to X, Y, Z with no connections to U, V, W.
For the high speed (wye) to U, V, W with X, Y, Z shorted together.
So this is what it must be. Wound as a 4 pole with the ability to parallel a pair of the poles to
produce a 2 Pole config.
2 sod 3 ph 220v motor.jpg
Hope this worked!
...Lew...
JTiers
Posts: 422
Joined: Fri Jan 22, 2010 12:55 am
Location: Missouri

Re: On the MOTOR subject

Post by JTiers »

This sounds like the Dahlander" winding, which has the windings divided up and connected so that the delta windings are tapped in the middle. Both halves are in series for delta, but if the connection is made to the taps, and the original terminals are connected as a star point, half the windings are reversed.

That can be used to "split poles" so that in Y there are fewer (higher speed), and in Delta there are more (slower speed). You usually pay for this in efficiency.

Motors can also be made to have alternating poles for high speed, and all wound poles of one polarity for slow.... the opposite poles then appear between the would poles, called "consequent pole" winding.
User avatar
tornitore45
Posts: 2077
Joined: Tue Apr 18, 2006 12:24 am
Location: USA Texas, Austin

Re: On the MOTOR subject

Post by tornitore45 »

1750 rpm (it isn't rpm it's what ever the Italians use)
The Italians say RPM for "Rivoluzioni Per Minuto" unless they are colloquial and say Giri Al Minuto (turns) but unlikely on a nameplate.
Mauro Gaetano
in Austin TX
Lew Hartswick
Posts: 775
Joined: Sat Jan 04, 2003 10:45 am
Location: Albuquerque NM

Re: On the MOTOR subject

Post by Lew Hartswick »

tornitore45 wrote:
1750 rpm (it isn't rpm it's what ever the Italians use)
The Italians say RPM for "Rivoluzioni Per Minuto" unless they are colloquial and say Giri Al Minuto (turns) but unlikely on a nameplate.
As a matter of fact I'm pretty sure that is what it said. I know I didn't recognize it but the numbers
made it what it had to be. GAM I'll get the photo of the plate next week and verify it. Should
have kept it and posted it but the teacher was the one in contact with the new owner of the
machine. The one in our woodshop is there but removing the covers is not going to happen again
if I have to do it. :-)
...lew...
Post Reply