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Anonymous Poster #1

Star Delta Starter Motor Is Not Running At Delta

03/18/2017 1:34 PM

hello guys i have a 18.5 kw motor controlled by star delta starter, which is plug to blower to ahu.

problem is when i start the motor first in star it will run till timer control 6s later it will changeover to delta in starter but the motor is not running at delta.

so i checked the motor current when it starts , starting current is 72 amps showing later it will decrease to 12 amps in star after change over to delta same 0 amps is showing ,

later i check the continuity resistance of motor its balance ,

what would be the problem please suggest me

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#1

Re: Star Delta Starter Motor Is Not Running At Delta

03/18/2017 5:57 PM

Delta contactor coil burned out, or open circuit feeding it.

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#2

Re: Star Delta Starter Motor Is Not Running At Delta

03/18/2017 8:51 PM

>There are 3(+) pages on CR4® on this very subject< You found CR4® by searching the internet, so click on the highlighted link and educate yourself

In another words, Do Your Own HomeWork!

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#10
In reply to #2

Re: Star Delta Starter Motor Is Not Running At Delta

03/20/2017 2:56 PM

Didn't AP#1 post this topic a couple weeks ago?

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#3

Re: Star Delta Starter Motor Is Not Running At Delta

03/18/2017 10:53 PM

Use this simpler step to check your star delta starter condition.

Step:

1) Dismantle out the 6 wire to to your motor at the contactor side or at the star delta terminal side. This is to test the circuit condition.

2) Put the timer to a longer time about 30 sec

3) Press the start push button

4) The star and the main contactor will energize.

5) Check the 3 phase voltage at the Main contactor (Bottom side terminal) and the continuity resistance at the star contactor. Make sure you get 3 phase voltage at the Main contactor and the continuity at the star point contactor.

6) Wait till the Delta contactor energize

7) Check the Delta 3 phase voltage at the Delta contactor (bottom side terminal of the contactor) and make sure you get 3 phase supply.

If any one of the contactor phase does not get any voltage reading your wiring are wrong. Basically by seeing you can able to see what wrong with the star delta starter already.

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#11
In reply to #3

Re: Star Delta Starter Motor Is Not Running At Delta

03/20/2017 2:57 PM

How is he supposed to measure voltage and continuity at the same time with the feeder energized?

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#24
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Re: Star Delta Starter Motor Is Not Running At Delta

03/23/2017 4:55 AM

The motor wire has been removed out from the contactor so during when the you start the star delta starter, the main contactor and the star contactor will energise. He only need to measure the continuity of the star point contactor only.

Generally, in this case is either the Delta contactor is not energizing or the Delta of the motor winding are connected wrongly in which the U1 and U2 are connected at the same Red phase, V1 and V2 are connected at the same Yellow phase and W1 and W2 are connected at the same Blue phase. During the Starter in Star point stage, the motor will run as the U2,V2 and W2 are connected in star point. But during the Delta Stage the motor will not run if the connection is wrong.

During the delta stage the Motor winding U1 in the KM should be in Red Phase where else Motor winding U2 in KD should be in Yellow Phase, Motor winding V1 in the KM should be in Yellow Phase where else Motor winding V2 in KD should be in Blue Phase, and , Motor winding W1 in the KM should be in Blue Phase where else Motor winding W2 in KD should be in Red Phase.

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#4

Re: Star Delta Starter Motor Is Not Running At Delta

03/18/2017 11:50 PM

The problem would be you!

you are not qualified to hold a screwdriver and fault find!

So.. save yourself a lot of heartache and find someone who can solve your problem in real time, right there on the job!

This CANNOT be fixed via email

Put the screwdriver down, back away to the office, pick up the phone and call a qualified industrial electrician!

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#5

Re: Star Delta Starter Motor Is Not Running At Delta

03/19/2017 4:13 AM

We would be FAR more happy to help you if you joined CR4 and gave full details of yourself.

Also, do remember that the possible voltages pose a danger to life and limb, with you not understanding the problem, we might accidentally instigate your death, by remote control, accidentally of course!!

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#6
In reply to #5

Re: Star Delta Starter Motor Is Not Running At Delta

03/19/2017 1:36 PM

It is not possible to post on CR4 without being a member - this has been the case for a long time - thought you'd have known that by now!

The OP (AP1) has chosen to conceal their identity.

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#7
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Re: Star Delta Starter Motor Is Not Running At Delta

03/19/2017 2:29 PM

Does that make the slightest difference? Certainly not for me personally......

I see no logical reason to be AP.....

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#8
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Re: Star Delta Starter Motor Is Not Running At Delta

03/19/2017 9:02 PM

Logical reason is because their in over their head

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#15
In reply to #5

Re: Star Delta Starter Motor Is Not Running At Delta

03/21/2017 4:53 AM

Going overboard on exclamation marks again, are we?

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#16
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Re: Star Delta Starter Motor Is Not Running At Delta

03/21/2017 8:39 AM

"What others say about you reveals more about them, than it does you." Anon.

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#18
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Re: Star Delta Starter Motor Is Not Running At Delta

03/22/2017 9:46 AM

And the corollary: "What you say about others reveals more about you than it does them."

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#19
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Re: Star Delta Starter Motor Is Not Running At Delta

03/22/2017 1:27 PM

What I posted, which seems to have upset some here was :-

We would be FAR more happy to help you if you joined CR4 and gave full details of yourself.

Also, do remember that the possible voltages pose a danger to life and limb, with you not understanding the problem, we might accidentally instigate your death, by remote control, accidentally of course!!

To someone posting Anonymously......

Come on Guys, give me a break!!

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#20
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Re: Star Delta Starter Motor Is Not Running At Delta

03/22/2017 2:08 PM

Uhhh...I was sort of lamely trying to be supportive to you, Andy. I don't however, like the idea that one or all of us might say something that would give the AP permission to become a crispy critter.

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#21
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Re: Star Delta Starter Motor Is Not Running At Delta

03/22/2017 3:28 PM

Thanks for the support.

Obviously I feel the same way.....even if we would never actually know if he/she died....that does not remove responsible posting, from both OP and us answering....

Thanks again.

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#22
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Re: Star Delta Starter Motor Is Not Running At Delta

03/22/2017 3:40 PM

Happy 2nd day of spring! or is it the third?

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#23
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Re: Star Delta Starter Motor Is Not Running At Delta

03/22/2017 5:00 PM

It was the Vernal Equinox......

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#25
In reply to #23

Re: Star Delta Starter Motor Is Not Running At Delta

03/23/2017 9:25 AM

Thank you most astute traveler, bon voyage on today's journey!

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#9

Re: Star Delta Starter Motor Is Not Running At Delta

03/20/2017 10:19 AM

There is no rocket science involved here. If your motor has zero current when the starter switches over to Delta, it's because something is wired wrong. There is nothing that could be wrong inside of the motor that would result in ZERO current flow if connected correctly. Start over, ASSume nothing.

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#12
In reply to #9

Re: Star Delta Starter Motor Is Not Running At Delta

03/20/2017 2:59 PM

I think you hit the nail on the head there! Somebody be thinking the electrons want to go, but the road block is up, and the electrons are smashing into that fence.

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#13
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Re: Star Delta Starter Motor Is Not Running At Delta

03/20/2017 8:30 PM

Or the drawbridge is up!

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#14
In reply to #9

Re: Star Delta Starter Motor Is Not Running At Delta

03/20/2017 8:38 PM

Here's a basic diagram.

From this diagram, Starting means you close K1 and K3, then after a few seconds, you open K3 and then close K2. If someone inadvertently put the coil of K1 through a NO interlock of K3, then when K3 drops out, so does K1 and the motor stops even though K2 is energized. People get really confused with Star-Delta starters, I'd look for something stupid like that.

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#17
In reply to #14

Re: Star Delta Starter Motor Is Not Running At Delta

03/22/2017 9:45 AM

Yes, it is generally a sign of someone up to the short nose hairs in water when they start off by saying, "it definitely cannot be this".

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