Motor Wdg. Start And End Lead Identification.

Can you describe the motor?

Like;

how big is it?

or anything written on it?

or what it came out of?

or where you found it?

Can you post a picture of it?

Any of the above may get the possibilities down below 10,000

The most simple test for a motor is continuity. Insulation tests require a bit of experience. Go away and find what you want to do!

Me, i rkn u sd bk juu. Only i sdf rank.

Wdyr

Cheers Mark N.

PS. 7+1 @ >1

Would some kind reader please translate the above posts into something intelligible?

Some time it is possible to do this with visual inspection, but I cant tell you how to it from far.But there are other inspection method that can help you to group all starting ends and finishing ends of winding.

Check inductance L of winding 1 Between two ends

Connect winding 1 in series with winding 2 and check cumulative inductance. See if inductance is Increased (doubled) or decreased (zero)

If increased, means two ends connected for series connection are odd (finish of one winding and start of another winding) and if decreased, means two ends connected for series connection are same(either starting or finishing ends)

You can do this with all windings and make two group.

Keep in mind this methode is not always correct. It is totally correct when you are dealing with 2 coils in a transformer, when they are on the same leg. In 3 phase motor with 6 leads, the coils are fysically displaced over 120° . The inductances will not increase to double are decrease to zero.

Thats why I have used both the words increased (double), Obviously if it don't double then it is going to increase, isn't that good enough to check the polarity,This method work fine and there is no doubt about that,Of course there can be many more ways but thats different issue,

Basic Idea is inductance in series will increase or decrease depending on what way you connect it, no matter how far they are kept and what Angle they are oriented,

I apply this method but in both conditions inductance value remain constant..

By checking the continuity with a continuit tester, you can seperate three windinsg now. Do a polarity test, with a cell & a Galvnometer.

I doubt, I think galvanometer will swing left or right depending on cell direction, not on the reversal of winding coil.

I am sorry! I have not explained the procedure of a polarity test. But, I have done so in the past. With careful polarity connections of the cell & the test winding as well as te Galvanometer & the check windings, it is very much possible to identify the star & end terminals of the windings.

hi dear,

thanks for vr. gud answer.

Regards.

I smell smoke.

You offered a good answer. But based on the light information and the spelling/grammar I don't have confidence for the poster. Maybe he can get his hands on a galvanometer or someone who knows how to use one and perform a few test runs on a set of labeled windings. Going in blind most people don't hit a home run at their 1st at bat.

I had a college professor for an electrical course who had a few sayings. His favorite one was, "electricity never forgets, you do, and when you do electricity will remind you".

low voltage batteries like 6volts can not harm human so long both terminals are not pierced in body.or user push terminals in mouth.

I think professor forget to tell you this.

thank you for those few kind words.. yes I know its a good answer, as it was voted so the last time I posted it.

However your further comments regarding the OP

"But based on the light information and the spelling/grammar I don't have confidence for the poster."

It is not our place to comment on the education or the comprehension of the OP as to their understanding of English, as English MAY NOT be their first language. Therefore, we can and must TRY to understand what the OP is trying to ask, in a foreign language, in their effort to communicate.

I speak Arabic, not as fluent as I use to, and as a speaker of another language, it is EXTREMELY hard, as English is to non-speakers.

I suggest that you do not comment on the understanding or comprehension of other users of this forum.

I look at it like this.... if the OP has the intelligence to ask the question then he certainly has the inteligence to comprehend a simply explained answer.

As you speak English, all be it American English.. it is for you to decide if you can understand what the OP is asking, if not then ask another question to clear up YOUR mis-understanding of the question.. or you don't offer any answer.

Maybe your professor should have told you if you have nothing to say, say nothing.

I do not write this as an attack on you, but as a caution to your attitude as a new-bee in CR4.. The object is to help, not condemn... yes there are stupid people out there.. but do not get drawn in.

So please be nice and offer constructive and helpful comments.

Have a great day

My comment was on clarity, not the posters intelligence. Thanks for the condescending reprimand but I'll conduct myself according to my standards, not ones you lay down for me.

Have a nice day :)

Again.. I have to say.. if English is NOT the OP's first language then it is up to the English speakers of this forum to ensure WE have the intelligence & comprehension to understand what they want.

As for condescending.. I haven't even started if you want condescending.. and as for my standards, not mine at all, just a gentle reminder of the common standards of manners, decency and respect that should be applied here.

I agree not the clearest of questions.. however.. it was to me a lot clearer than some of the question I get asked by my trainees in Libya, Oman and other overseas countries I work in.

If you get a rise out of making fun as you've tried to do with the OP, then carry on.. however you will very quickly find your posts removed and you will find the forum will turn on you.

Again I say, I'm not having a go at you... just cool the derogatory comments.. and you will find this forum a great place to be.. and thanks.. having a great day

Are you talking of that initial back EMF glitch? That seams the only way to me with this method.

Hi Brich,

I agree with your method of using the 'Flick' test and have used this test many times to confirm the connections on CT's (both protection and metering).

One thing that I can add is that you do not need to use a centre zero galvanometer (although this would be the right meter to use) but can use a normal analogue meter set to its lowest DCV range. When you carry out the 'flick' test as you have described you would note the needle flick very slightly in one direction (either up or down).

If all three coils induce a voltage of the same polarity in the test winding (all positive or all negative deflections) then you have proved the connection of the windings. If however one reading is different then this coil is the odd one out and should be reversed.

Just as a matter of interest I have normally just used a normal 1,5 volt torch battery (D cell) to test the CT's.

Perhaps the smoke that the one poster smells is from whatever he is smoking that causes him to believe he is an expert on everything! As we would say in SA - Siestog & Shame Nogal!

Hi Keith

I guess you could use a normal analogue meter.. never tried it myself... cannot see why it would not work. I'll remember that next time I can't find a center zero type.

Never tried the flick test on CT's.. must give that a go...

As for the smoke comment.. I'll not elaborate to any great degree as one would not wish to be dubbed condesending!!

Yes,we have the simple continuity test using a digital or analogue multimeter.

If the 6nos leads are free or connected already either in delta or star formation without any identification,remove the connections and free the 6nos leads.Set your meter at the ohm value for continuity test or use the buzzer.

Pick any one lead of the 6 leads,connect one probe(say RED) to the lead and touch the other 5 leads one after the other with the second probe(BLACK).Any lead that makes the buzzer to sound or gives continuity deflection if analogue meter is used,is the end lead of that winding,mark the leads(winding) as U1,U2.Pick another one lead of the remaining 4 leads,touch the other 3 leads,when there is sound or continuity deflection on any of the 3 leads,mark the two leads(WINDING) as V1,V2.the last 2 leads(WINDING) will be will be W1,W2.

For your motor connection in star,link W2 to U2 to V2 and take your supply L1 L2 L3 to U1 V1 W1.For delta connection,link U1 to W2,V1 to U2,W1 to V2,and take your supply L1 L2 L3 to U1 V1 W1.

Hi Patrick,

The test you describe identifies the three windings but does not confirm that the windings are connected correctly i.e. that U1, V1 & W1 are all the 'start' ends of the winding and U2, V2 & W2 are all the 'finish' ends of the windings which is, I believe, what the OP's question concerned.

If a motor is connected to the supply (star or delta connection) with any one winding reversed then the motor, if it starts at all, will not operate correctly and will overload.

The 'flick' test described by Brich and the series test described by myself will both identify the reversed winding without opening the motor.

Hope this clears up the difference between identifying the three windings and confirming that all three windings are connected in the same direction.

Regards,

Keith

hello keith,

If u trace the windings and connections proper in any form of arrangement as far as u have 6 free terminal leads,and you have your U1,U2;V1,V2;W1,W2 and having made your star or delta connection,a winding in star will have 220v each for a 380v source,while in delta,a winding will have 380v each.For your L1,L2,L3 supply to U1,V1,W1,each winding of U1,U2;V1,V2;W1,W2 when traced will give you L1L2(380V),L2L3(380V),L3L1(380V) RESPECTIVELY.

Hi Patrick,

I am definitely not trying to be argumentative but you seem to believe that once you have identified your three coils then, even if one coil is connected in the wrong direction, when you connect up in either star or delta that the motor will run OK.

My suggestion to you would be to carry out a practical test by taking a motor that is operating correctly and reverse the connection of one winding. Using your ampmeter please note the difference on each phase a) from the original correctly connected motor and the b) from the same motor with the one winding connected in reverse.

Example is for motor connected in delta but you can connect in star if you prefer.

The original motor would be connected - U2 bridged to V1, V2 bridged to W1 and W2 bridged to U1. The supply would then be applied to U1, V1 and W1.

Now reverse one winding and retest. The connection (with winding 'U' reversed) would now be - U1 bridged to V1, V2 bridged to W1 and W2 bridged to U2. The supply would then be applied to U2, V1 and W1.

I am sure after you have run this test and tried to run the motor under load you will then understand the OP's conundrum - he had six unmarked wires and has realised the importance of connecting the motor correctly - therefore the question in his posting.

Should you still be unconvinced then I would suggest you have a chat with your local motor rewind shop engineer who can explain it all to you.

Regards,

Keith

Patrick

why make work for yourself and what you have written in your two posts is just dangerous, and not good practice.. and if you think that just by finding the ends and connecting them to the power it will work... you by admission don't have the knowledge you think you have.

You have not tried your method, if you had you would not suggest it. As suggested by Keith, you try it, but before you do, BOLT down the motor, to stop it vibrating off the bench..

The only way is to use the flick test method.. or rewind the motor.

And yes the OP has not been back and yes we are ALL assuming he/we are talking about a 3 phase motor.

Continuity, IR test, read for diagram, connect, IR test again. If you electrical you should know how the basic motor winding.

Just out of interest, and I just skimmed, and it appears the OP has not been back: when/how did we decide it was a particular type of motor? or even AC?

Just curious

Hi 34point5,

No, it doesn't appear as if the OP has returned to the discussion however that is irrelevant for me as his question has started an interesting discussion which is why I subscribe to CR4 in the first place. Just for your information the OP may have read all the replies in the discussion and just not posted his response.

I should point out that his description of a motor with six leads led us to believe that it was indeed a 3 phase AC motor and if you have a look at my postings you will note that I categorically stated that I was referring to a 3 phase AC motor with the exception of the post where I referred to the 'flick' test as used (in my experience) to check CT's.

As in all forums there will be those who choose to post nonsense and ridicule posters who struggle with their use of English. One should remember that a posters inability to communicate clearly in English in no way indicates that they are technically or mentally incompetant. The fact that you are reading this on a Chinese or Korean manufactured monitor that has been designed and manufactured by people who have no knowledge of even one English word should bear witness to this.

When reading through CR4 one should bear in mind that there are 'diamonds amongst the stones' and it is these diamonds that make it such an interesting and informative site.

You actually make a point of saying that the OP has not returned - this could probably be explained and caused by the poor responses to his posting. I actually live in a country where we have eleven official languages and am very aware of the arrogant belief held by many English speakers that you are uneducated if you are not fluent in English. I can imagine an English speaker arriving on Mars and asking a Martian "Do you speak English?"

I qualified over 42 years ago and one of my ambitions is to share my technical experience with the newly qualified Engineers and Technicians. Even today I believe that if I don't learn something during the course of the day it will have been a day wasted. All I am expecting is for the rest of the posters who believe that their brand of wit (asking what colour the motor is or smelling smoke over the net) should try to restrict their comments to comments that reflect their 'superior knowledge' and maintain their dignity.

Regards,

Keith

had to give a GA!

I did not realize that in SA you were so articulate... joking.. I promise.. :)

Good-o Keith

Do you have some ESL issue with post #1?

Or, with my having a bit of a hoot with Brich, who is obviously 'concerned' by 'creative solving' outcomes - all based on 'assume'.

You have no way of knowing if in fact these wires are 'actually encoded' - by say stripes - the OP can't grasp the significance of. Or vary in diameter - a whole other set of variables.

But for what it's worth my history on CR4 should tell you: You have no way of 'mounting an ESL smear campaign' on me especially.

If you wish, you may post in Afrikaans and I will be one of those that understand.

So what is your actual 'point'?

As cmaguna (OP) hasn't found his way back, YET ... I'll throw-in. (Perhaps he has just figured out how to SEARCH for an identical post, before posting his own...?)

For ease of typing, I repeat my Post (#6) at THIS THREAD ... [quite similar to the GA by 34point5 (Post#1)] ... Note: this is a "link-within-a-link" response...

A simple method for identifying the start and end connections are:

Take windings U1-U2 & V1-V2. connect them in series (short U2 and V1 ) with a lamp(230V) and apply a 1 phase voltage across that. If the voltage across the lamp reads less than 230V(approx. 220V) then the start and end connections are correct. If the voltage across the lamp reads same as that of applied voltage then we have reverse the start and end connections. Reapeat the same for V1-V2 & W1-W2.

would you like to post a diagram for your suggestion?