Identifying Induction Motor Terminals

There is only 2 3 phase combinations RYB or RBY.Go ahead.

My question is how to determine in and out of each phase not the phase sequence

Please use the CR4 private mail system and send a message to

electricalexpert65

He has written an excellent paper on this. If you ask nicely, he may give it to you.

You beat me by 3 minutes!

His posts can be searched also.

KVS! Thanks for the compliment! I will surely reply the OP in this forum iteslf.

I think you mixed up with in/ out as well. First with multimeter identify three windings and separate them. First "star connect" assumed three winding as U1, V1, & W1. Use low rating MCB and try to rotate motor. If MCB trips, interchange U1 with U2 and repeat the test. Still MCB trips, change back U1 & U2 and now try with V1 & V2; the other method is open the motor and identify in & out connections. One more method is apply low voltage DC and identify North pole south poles of each winding and separate inner & outer connections. All the best!

very simple dear....

first open all six connections

just take continuity tester take one terminal out of six say V1 and check continuity in which you get that's V2 same prosses for all......

or

give singal phase to one terminal say V1 and check return supply where you get it that's V2

déjà moo?

Hi Keith,

Nice isn't it? It was the "very simple, dear..." that triggered it. If you see this whole thread, there are experts like EE65, Yuri, kvsubramaniam and then we have these who are so smug in their ignorance. Must be nice.

As you say, most people can't be bothered to search. Why bother, when it is easier to post, and some idiot like me will tell where to go for the answer, if not give it already?

One of the moderators (Savvy ... was that you?) gave an excellent post on 'How to search CR4' or something like it. To no one's surprise, only the experts who never have to search contributed, asked questions, gave suggestions etc. Not one newbie came and said that he/she has been helped by that thread.

So.....i am all for a band of experts, but am not so sure if it will be successful. i am all for it though.

Good thoughts anyway, thanks.

PS: i almost overlooked the VERY important point in your post... the potentially LETHAL wrong answers given by some ignoramuses (ignorami ?) wallowing in their ignorance. These are usually pounced on by the experts, but you are right...they shouldn't be allowed to appear in the first place !!!

Keith,

After reading some of the posts in CR4 and other similar forums online, I could not agree with you more. There is two sides to this situation:

1. The experts get tired of always answering the same questions so they start referencing previous answers. This is fair and understandable. The danger is that this method eventually turns the forum into a "wikipedia style" website and you loose that sharp interaction with the people whose knowledge make really cool things happen every day.

2. There are great answers that have already been posted and people deserve to know about them. The person in doubt should at least make a small effort of searching through the forums. Perhaps someone already not only answered his question but also answered questions that will come up in the future.

Experts should be careful not to reference every answer to the search bar-on the other hand-great answers should be resurrected by guiding the person in doubt back a previous discussion. It's a balance.

Use CONTUNITY option in multi-meter to find the U1&U2, V1&V2 AND W1&W2.. since we have only 6 terminals..

when u identify the terminals, find in the name plate wether it is given STAR connected or DELTA connected motor...

if not given...

if u want STAR connection, SHORT the U1,V1,W1 OR U2,V2,W2... at last u will have 3 terminals.

if u DELTA connection SHORT U2-V1, V2-W1, W2-U1... at last u will have 3 terminals....

hope it is clear...

Spot on! When I was young and green behind the ears we used to call it a Flick Test.

If I don't have a galvanometer what instrument that i use? or can I use multimeter?

Just take continuity tester

you will find 3 seperate windings one with U1 - U2

second with V1 - V2

U1 V1 W1 thhird with W1 - W2

o o o

W2 U2 V2

o o o

For a cold test, a nice post by electricalexpert65, but if one wants to test with applying power, then follow the post by kvsubramanyam. I do the same practice.

GA. I never thought of this. I see a good logic in this method; I shall try. Thanks a lot.

Thanks to everybody;

:)

Hi One & All,

Here is the a drawing that should help you:

Best luck and let us know how things come out.

BEN

Ben, this is a connection drawing for a two speed dahlander motor. The Topic opener asked for U1-U2, V1-V2, W1-W2 . This tells us he has a one speed motor.

Connection diagrams are highly different !!!

Since you want solid reasons, contact the motor manufacturer