Six wire- two speed motor

[ballpeen]

Hello all. This is my first post so bear with me. Recently I have been promoted to a lead person job and fill in when my Supervisor is out. This past week one of the shop personnel went out to install a newly rewound motor and could not get it to work right. He said it sounded like it was single-phasing.
We ended up taking the original motor back to the shop and repairing the damaged shaft, which was the reason why it was taken out in the first place, and fixing that.
Meanwhile I had them bring the motor in question back to the shop for some experimenting. When I called the motor repair facility, they claimed the motor should be fine, and to check with my Supervisor to see how to hook it up. That was not possible at that time.
The shop guys were able to get the motor to run by shorting 3 leads together and using the other 3 as the phase leads. But have been unsuccessful in getting a 2 speed effect.One of them mentioned something about a "consequential pole" but was unsure if this was the case.
My main forte' is machining and welding, but I have taken alot of electrical courses and from what I see it is a matter of utilizing a different set of poles to get the desired speeds and it shows that in the original prints. I know the fewer poles, the faster the motor will run, trying to play catch up with the rotation of the fields.
Now when we received this motor it had markings 1 thru 6 on the wires, but no indication as to how they are connected.
Its either this motor will only have 1 speed or it hasn't been rewound right for the intended use as required by the manufacturer.
Does anyone here know if it is possible to derive 2 speeds from this motor?? Thanx.

 

[electricpete]

Go to jolietequipment.com

Click on EASA Handbook (it's near the center of the page halfway down)

Click on "Term. Marking-Conn. 3Ph Mtrs-Two Speed-Single Winding"

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[electricpete]

Interesting, if you search for the info thru google, it takes you to the same place, but this time it gives you a link to work with.

A more direct link to the same info as above:

http://www.joliet-equipment.com/ter...tions-3ph_motors-two_speed-single_winding.htm

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[aolalde]

Ballpeen, Your motor is one of the following types:

Constant Torque 2 Speeds. The HP shown on the nameplate are in the ratio of ½, if so, connect:

LOW SPEED ( Lower HP)
Line 1 to motor Terminal 1
Line 2 to motor terminal 2
Line 3 to motor terminal 3
Leave motor terminals 4,5 & 6 open and insulated from each other. This connection is 1 circuit Delta.

HIGH Speed (Higher HP)
line 1 to motor terminal 6
Line 2 to motor terminal 4
Line 3 to motor terminal 5
Short circuit 1,2&3 (neutral) this connection is 2 Wye.

Constant Horsepower 2 Speed. The HP shown on the nameplate are the same for both speeds, connect:

LOW SPEED
Line 1 to motor Terminal 1
Line 2 to motor terminal 2
Line 3 to motor terminal 3
Short circuit motor terminals 4,5 & 6 to make the neutral. This connection is 2 circuits Wye.


HIGH Speed
Line 1 to motor terminal 6
Line 2 to motor terminal 4
Line 3 to motor terminal 5
Leave motor terminal 1,2&3 open and insulated from each other. The connection is 1circuit delta.

 

[ballpeen]

Hey thanks Pete for the help on the website. I printed it off and took it to work with me today.This should at least get them going in the right direction. And to you aolalde, for writing up all of those configurations. As stated they could get it to go in the slow speed but, not the high speed. The slower speed is supposed to be 1400 rpm and the higher is supposed to be 2800. I would assume at 50 hertz, where this is a German motor. Probably at 60 hertz it would be 1800 and 3600? Also I am finding out today that there is some contactors that are pulled in at one speed and not the other, which are internal to the machine. So its imperative that the connections are right. One other thing is that the motor cannot start at the 3600 rpm setting. It is required that it already be rotating at the 1800 rpm setting. Which may explain why they couldn't get it to start wired that way at the test bench.
Anyway I'll keep you guys up to date on what the end result is but, I think its beginning to look like the motor may have been wired right after all. Ballpeen.

 

[aolalde]

Ballpeen.
Look for some wiring diagram on the motor nameplates. Yes if the motor is connected on 60 HZ supply the speeds will increase proportional to the frequency increase.
Be careful since the motor performance changes when the frequency supplied is not that specified on the motor nameplate.

 

[petronila]

Hello ballpen,

In a Dahllander connection we can find three different kind of two speed motors (With only one winding):

Constant Horse Power: Same Horse Power at Both Speeds.

Speed L1 L2 L3 Comments Connection
High 6 4 5 1&2&3 Open 1 Delta
Low 1 2 3 4-5-6 Join 2 Wye

Variable Torque: Low horsepower is One-Fourth of High Speed Horse Power.

Speed L1 L2 L3 Comments Connection
High 6 4 5 1&2&3 Join 2 Wye
Low 1 2 3 4-5-6 Open 1 Wye

Constant Torque: Low Speed Horse Power is Half of High Speed Horse Power.

Speed L1 L2 L3 Comments Connection
High 6 4 5 1&2&3 Join 2 Wye
Low 1 2 3 4-5-6 Open 1 Delta

Comments:
1. I think your shop most send a Wiring diagram each they perform a repair in special motors.
2. Check if your electricians needs to know more about this special motors.Try with the shop some course about it.
3. Did you check if the name plate is installed on the motor? Usually the connection diagram is showed by the name plate.

Regards

Petronila

 

[LionelHutz]

Why can't the motor start on the high speed winding?

 

[ballpeen]

Well Lionel when the electrician tried to hook it up and run on the higher speed, it would only hum. So I again assume that it may be required to be rotating..... One thing I did notice today looking at the nameplate was that it said wye wye / delta. Which I guess must be an indication of the wiring configuration...... As far as the motor shop, they are willing to work with us on this problem. Probably in order to keep our business. As we do have some rewinding jobs particularly on our pumps. I personally feel that they should be marking the motor covers with necessary wiring so they can be hooked up as they were originally. They are marking the wires 1 thru 6 but, it confuses our electricians as to how to do the hookup. Another thing I heard today was that the electrical print shows an internal thermal fuse and the rewound motor does not have it. Would this affect the motor wiring at all? Maybe the logics of the machine require it to be there and it isn't? Ballpeen.

 

[aolalde]

Wye Wye means 2 circuit wye, Delta means 1 circuit delta.
If the motor hums on high speed when the shaft is free (no load) the winding is wrong.
The thermal protector is an option and does not afect the magnetic performance as far as the windings are correct.
Two speed starters make the required connection when the six motor leads are connected to the corresponding ports of the starter.

 

[LionelHutz]

I can't see any reason why a typical 2-speed motor could not accelerate to full speed starting from a stop using either connection. I was just wondering if there was some special reason.

Your wye wye/delta on the nameplate would suggest that either the constant HP or constant torque connection will make it work. You never told us which connections made it work.

 

[ballpeen]

I'll post back soon with what they ended up with but I guess it was wound right, it was just a matter of the connection. I think it was the 4-5-6 hooked together and the phase leads being 1-2-3. I also want to post what the exact nameplate lettering was as well. As far as starting at the high speed, this is what I was told about it. Again I am not an electrician by trade but, I have taken quite a few courses on the subject and am learning as I go along. Ballpeen.

 

[petronila]

Hello ballpen,

If the name plate said wye wye/delta then this is a Two Speed one winding Torque Constant Motor:

Constant Torque: Low Speed Horse Power is Half of High Speed Horse Power.

Speed L1 L2 L3 Comments Connection
High 6 4 5 1&2&3 Join 2 Wye
Low 1 2 3 4-5-6 Open 1 Delta

I think the motor could be fine but when your electrician made the Connection could perform a standard type:

Standard Wye 6-4-5 join and L1-- 1, L2-- 2, L3--3.Then the motor is wrong connected.Good Connection : High L1-6 l2- 4 l3-- 5 1&2&3 Join 2 Wye

Standard Delta L1-- 1&6, L2-- 2&4, L3-- 3&5 and is wrong conected too.Good Connection : Low L1- 1 L2- 2 L3- 3 4-5-6 Open 1 Delta
This could explain why the motor don´t work proper.

Regards

Petronila

 

[ballpeen]

O.k. I'm back with some more info. on the motor problem. Sorry I haven't been here sooner but, things have been hectic. The exact nameplate info. is: LANDERT MOTOREN AG
No.82821/073 Typ.160W- 4/2F.6.2-03
3 phase S1 6.2/ 2.5 Kw
480 YY/? Volts 9.8/ 4.85 Amps
1770/ 3550/ min. Cos.? 60 Hz.
IS. KL. F IP54
PTC 130 Grad. C
ID 384033

Now with this motor hooked up with the test leads it will turn at the slow speed no problem, at the higher speed it will only turn at about an estimated 100 to 200 RPM's. when starting from a stop and with no load,and is quite noisy as was stated. One thing that did have to be done was, the wire markings had to be reversed in order to get the motor to run properly....... It has been taken back in preparation for use the next time it is needed, so we'll see. I hope this is enough info. because its all I can give you on this particular motor. Ballpeen.

 

[petronila]

Hello Ballpen,

In your first post you talk about the motor was rewound and you could not get it to work right and sounded like it was single-phasing. The above name plate belongs to one single winding/Two speed motor. This special motors have 6 wires and depending of the connection could run at high or low speed at only one voltage, in your case the high speed is 3550 and the low is 1770 RPM. and the main voltage is 480 V. The motor was manufactured by LANDERT MOTOREN AG from EUROPEAN (Swiss ).The problem could come from two sources: 1. Motor wrong rewounded, in this case the work shop did not made a good internal connection on the winding.
2. Incorrect external connection, in this case your electrician made wrong connections.
In my last post I was send all information about the NEMA external electrical wiring for this motor but taking acount this is a swiss motor here are the IEC Connection:

SPEED L1 L2 L3 COMMENTS Connection

High 2w 2u 2v 1u-1v-1w Join 2 Wye
LOW 1u 1v 1w 2u-2v-2w Open 1 Delta.

Best Regards

PETRONILA