By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Forum House Ad Zone



All Topics | Latest Posts

Search for:  in Thread Title in  
ray jones 121/11/2018 19:59:09
54 forum posts
29 photos


I have acquired a new unused milling machine, it is USA origin,

the motor is 3 phase 440v / 220v dual voltage, 2 horse power.

The motor has 9 wires. ( see plan sketch ) Cables are named

U1, U2, U5,, V1, V2 , V5

and W1, W2 , W5.

I have a standard 3 phase , 3 cable / live supply I.E. No neutral.

I am trying to wire it for standard 440 Volts. not 220 volts

any suggestions on which wires should be joined

and which should be connected to the live feed inputs please

many thanks RAY

motor wires.jpg







Edited By ray jones 1 on 21/11/2018 19:59:59

John Rudd21/11/2018 22:02:51
1452 forum posts
10 photos

For 415, ordinarily, you would common up the 1's (or the 2's ) and feed the phases to the 2's ( or the 1's )

Could be the motor is dual speed too...any label on the motor?


(Didnt know they used 415 ac 3 phase....usually 110 single or 220 multi..)

Edited By John Rudd on 21/11/2018 22:05:01

Emgee21/11/2018 22:25:49
2409 forum posts
287 photos

Hi Ray

Could be some variation of a Dahlander multi speed circuit needed, only thing that concerns me is the 220 or 400v choice.
Is there any speed change switch at the head/motor end or are all 9 wires taken to a control box ?

Can you show a picture of the motor plate ?


Les Jones 121/11/2018 22:35:53
2255 forum posts
156 photos

I have found this web page by serching for "American three phase dual voltage motors" Your motor could be this configuration but with a different numbering system for the connections. You should be able to confirm if this is the case by measuring resitsnce values between the terminals. Even if we confirm this to be the case I don't know how to work out the way it should be connected to get the phasing of the three separate coils matched to the three coils allready connected in star configuration. If you post a picture of the label on the motor it may give us a clue to the numbering system used by the manufacturer.


Robbo23/11/2018 14:54:37
1504 forum posts
142 photos

All I can offer on this is a pic of the data plate of an American 9-wire 3-phase dual voltage motor that I have.

This seems to follow the wiring shown in Les's link. The actual wires are all the same colour and are numbered from 1 thru 9. I have it set up for low voltage Delta via a VFD, so no point in showing the actual wiring. At first I found it confusing that 3 wires (4, 5, 6) are connected together when in Delta when on our 6 wire configuration this would be for Star. The "Y CONN" refers to the connections to the left. Sorry this is all numbers and not number and letter combinations.


John Rudd23/11/2018 16:11:54
1452 forum posts
10 photos

looks to me that your 3 phases are connected to terminals ( wires..) 1,2 and 3. then 9-6,8-5 and 7-4 are joined as pairs....Its a single speed motor.....the star point  is 4,5 and 5

So each phase has two coils in series for 440v or in parallel for for you running it from a vfd with a 240 output you must have it wired in lo voltage format?


Else I'm completely wrong!

Edited By John Rudd on 23/11/2018 16:15:28

Les Jones 123/11/2018 17:12:30
2255 forum posts
156 photos

Hi Robbo & John,
I agree that this is the way it is probably wired. All the information I found on the web uses the same numbering system as your's (Robbo.) I did not find any with the same numbering system as Ray's motor. It should be easy to identify the windings that are already connected in star with resistance measurments. I imagine all the winding with the same letter are on the same phase. The only thing left is to work out the polarity of the three separate windings. The only way I can think od doing this is to connect about 12 volts AC between two legs of the star connected winding (Let's say U & V ) then connect one of the other U wires to the U end of the star. Then measure from the voltage from the V end of the star to the end of the U winding that is not connected to the star. If the reading is greater than 12 volts then the polarity is correct. If it is less than 12 volts then the polarity is wrong. If the rotor was removed I would expect the reading to about 18 volts for the correct polarity or 6 volts for the wrong polarity. If the rotor is fitted then it will probably change these readings as it will behave like a transformer with shorted turns.
I have never played with this type of dual voltage motor so this is all theory. If Ray posts a picture of the data plate on the motor we may not need to do this. There could also be the required information inside the motor's connection box


Robbo23/11/2018 23:15:06
1504 forum posts
142 photos
Posted by John Rudd on 23/11/2018 16:11:54:

So each phase has two coils in series for 440v or in parallel for for you running it from a vfd with a 240 output you must have it wired in lo voltage format?

That's correct John. Wired as the right hand diagram. Works fine.

ray jones 126/11/2018 18:34:43
54 forum posts
29 photos

motor SERIES.jpgmotor VOLTS.jpgHi Apologies for the delay.

I Have now added photos of the Motor spec plate and wire instructions. It appears the Motor was factory pre motor PLATEa.jpgwired 240 volts, but as per wire plan can easily be wired for 440 volts. Thank you ray

Edited By ray jones 1 on 26/11/2018 18:35:19

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Latest Forum Posts
Support Our Partners
Eccentric July 5 2018
Rapid RC
Eccentric Engineering
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest