PLCS.net - Interactive Q & A

PLCS.net - Interactive Q & A (http://www.plctalk.net/qanda/index.php)
-   LIVE PLC Questions And Answers (http://www.plctalk.net/qanda/forumdisplay.php?f=2)
-   -   What are:Single-Rotation and Pole-Changing motors? (http://www.plctalk.net/qanda/showthread.php?t=113122)

kalabdel November 28th, 2017 10:45 PM

What are:Single-Rotation and Pole-Changing motors?
 
2 Attachment(s)
Hello everyone,

In the attached motor wiring there are three different types of motors shown, being: 1-Single-rotation motors, Pole-Changing motors and Dual-Voltage motors. Dual voltage I understand, the other two I don't.

Single rotation means I can not change the motor direction of rotation by switching two of the phases?
Also in the wrining shwon isn't the single-rotaion motor also dual voltage Wye and Delta?

Pole-Changing changes the motor speed? How does that work?


Edit:

One more question, what is temperature monitoring or rather how is it implemented in the motor? There's a small terminal block in the junction box that is marked R1 and R2 where do they connect to inside the motor and how are they used in c control circuit?

Thanks
Kal

Rob... November 29th, 2017 03:46 AM

Single rotation motor, from what I can see on that drawing is just a normal 3 phase squirrel cage motor. You can change the direction by swapping 2 phases.

Pole changing motors, from what it looks like and what I've worked on before, dependent on how you wire the motor at it's terminals dictated how many poles the winding have. So effectively its a duel speed motor.

R1 and R2 will be wired to some form of thermistor embedded in the motor winding's. Wire to a thermistor protection relay, this will trigger when the motor winding gets hot. If wired into the control circuit properly, it should stop the motor before irreversible winding damage has happened.

kalabdel November 29th, 2017 07:16 AM

Thanks Rob.

jrwb4gbm November 29th, 2017 08:07 AM

Single rotation motors may be referring to a motor with a mechanical device built into it to keep it from rotating in the opposite direction. An example might be a large deep well pump motor with threaded shaft couplings.

kalabdel November 29th, 2017 08:42 PM

Thanks jrwb4gbm.

shooter December 4th, 2017 04:37 PM

single rotation means, only one speed, but two directions,pole changing means the number of poles can be changed, meaning it has more speeds.
dual voltage means it can run on two voltages with same power.
wye is running with only 1/3 of power. .

kalabdel December 5th, 2017 01:08 PM

Thanks shooter. I emailed Lenze tech support and below is what they had to say. Has anyone ever needed to wire a motor so that it can be used with both high and low voltages?

Me:In one of your motor manuals I read a reference to a single rotation motor (see attachment) but I couldn't find a explanation as to what it actually is. I would appreciate a description of the function of a single rotation motor.

Lenze: Single rotation motors means that it can only run off low (208/230/265V) OR high voltage (400/480V) at a time. To change between low and high voltage, you will have to change the dog bones bridges in the terminal block connection as shown in the diagram in the attached document.

Me:

Thanks. These are the motors I'm familiar with but I take it that means that there are motors that can be wired to be used for high and low voltages? Do you have a manual or product catalogue of those motors?


Lenze: Lenze only offer single rotation motors in our current portfolio. We do not offer pole changing motors or dual voltage motors anymore.







ASF December 5th, 2017 04:09 PM

I suspect that demand for dual speed/dual voltage motors is dwindling rapidly these days. There's quite a lot of control circuitry involved in making one work, and with the price of VSD's getting ever lower, there's probably very few applications where it's worth the effort.

Mara December 6th, 2017 11:10 AM

Quote:

Originally Posted by ASF (Post 761162)
I suspect that demand for dual speed/dual voltage motors is dwindling rapidly these days.

Don't know about dual voltage motors but pole change motors are still very common in crane applications.

ASF December 6th, 2017 04:24 PM

That's true - probably one application where they'll hold onto relevance for a while longer.

just the cowboy December 7th, 2017 02:57 PM

Reduced voltage
 
Quote:

Originally Posted by kalabdel (Post 761141)
Thanks shooter. I emailed Lenze tech support and below is what they had to say. Has anyone ever needed to wire a motor so that it can be used with both high and low voltages?

Me:In one of your motor manuals I read a reference to a single rotation motor (see attachment) but I couldn't find a explanation as to what it actually is. I would appreciate a description of the function of a single rotation motor.

Lenze: Single rotation motors means that it can only run off low (208/230/265V) OR high voltage (400/480V) at a time. To change between low and high voltage, you will have to change the dog bones bridges in the terminal block connection as shown in the diagram in the attached document.

Me:
Thanks. These are the motors I'm familiar with but I take it that means that there are motors that can be wired to be used for high and low voltages? Do you have a manual or product catalogue of those motors?


Lenze: Lenze only offer single rotation motors in our current portfolio. We do not offer pole changing motors or dual voltage motors anymore.

The dual voltage motor is Wye/delta reduced voltage starting motor. It uses wye connections for starting then switchs over to delta connection for running

kalabdel December 7th, 2017 03:39 PM

Quote:

Originally Posted by just the cowboy (Post 761458)
The dual voltage motor is Wye/delta reduced voltage starting motor. It uses wye connections for starting then switchs over to delta connection for running

Oh, I see. That makes sense.

Cheers
Kal

shooter December 9th, 2017 10:53 AM

A normal dual voltage has 6 windings, instead of 3 so it just has more connections.
And yes there are also motors that run with only 3 windings, however this is not really dual voltage as the voltage must be root 3


All times are GMT -5. The time now is 10:00 AM.

.