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plckid
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Join Date: Aug 2010
Posts: 56

Control Circuit.

08/15/2010 8:15 AM

Hello experts.

I am a fresh grad. I did research on star delta wiring. I understood the main wiring diagram but what I dont understand is the control circuit. Can some one please expalain me. How this works . Thanks
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Pathfinder Tags: contactors control circuit star delta wiring
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PWSlack
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#1

Re: Explain me the control circuit.

08/15/2010 8:25 AM

Upon energising the control circuit, the star contactors energise. These are the one on the left and the one on the right.

When the timer runs out, the star point contactor on the right de-energises, and the delta contactor in the middle energises.

A wise installer will have fitted a mechanical interlock mechanism between the middle and the RHS ones, so that it is impossible for both these contactors to be closed at the same time, for to do so would take out the supply fuses.

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plckid
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#2
In reply to #1

Re: Explain me the control circuit.

08/15/2010 9:38 AM

Thanks . But what it is all the stuff in between i mean you have K1(13,14) S2,K2,. I want to understand that.
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lyn
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#3
In reply to #2

Re: Explain me the control circuit.

08/15/2010 10:01 AM

"But what it is all the stuff in between"

The stuff in between is what you were supposed to learn in school.
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plckid
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#5
In reply to #3

Re: Explain me the control circuit.

08/15/2010 11:57 AM

@lynlynch

I am a poor guy so did not go to a good school. I was not lucky as you. I studied on my own . So if cant help people dont write here. Take care
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lyn
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#6
In reply to #5

Re: Explain me the control circuit.

08/15/2010 12:17 PM

Perhaps it's a language thing. Your description of yourself, "I am a fresh grad. I did research on star delta wiring" would imply that you have formal education.

My mistake, I guess.

Lucky is a relative term.

I'm sorry that I couldn't help you in your quest for knowledge. But, that won't keep me from commenting from time to time, thanks anyway.

And finally, if you had begun this thread and the other one you posted with, "I am a poor guy so did go to a good school. I was not lucky as you. I studied on my own ." I would have tried to help you myself. Not really, Ohm's law was a TV show, right? If you can't touch it, I can't understand it.

Cheers.
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Anonymous Poster
#4
In reply to #2

Re: Explain me the control circuit.

08/15/2010 10:11 AM

those are the respective contacts(13,14 etc)of contactor K1/K2/K3. S1, S2 are the off/on push buttons. f2 is the overload thermal contact. beneath each contactor is shown its contact's state when de-energised.
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PWSlack
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#7
In reply to #2

Re: Explain me the control circuit.

08/16/2010 3:03 AM

The Ks are relay coils and their contacts. The Ss are switches or pushbuttons. The 13, 14, etc. are the terminal numbers on the individual devices. It is surprising that there are no wire numbers on the drawing....

What was the course that was studied, and what was the grade achieved, by the way?

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SHAMITHGAMBHIR1
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India - Member - design engineer Engineering Fields - Electrical Engineering - New Member United Arab Emirates - Member - New Member

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#8

Re: Control Circuit.

08/16/2010 4:21 AM

the plain rectangle s a coil (contactor (K), relay(R), ... etc) which energises upon a closed circuit.upon energisation their contacts change their position....i.e NO Becomes NC n viceversa...... the rectangle with a "X" extension s a timer fitted to a contactor.In your case this is an off delay timer...usually for a star delta starter we use an on delay timers fitted to main contactor......

off-delay-timer is a type of timer in which the contacts change position immediately when the coil is energized, but delay returning to their normal position when the coil is de-energized.now u don need 4 contactors for a star delta starter. jus 3 s sufficient. first check this website for basic understanding of components

http://www.toolingu.com/definition-460210-33823-off-delay-timer.html

if u ve read it thn i ll start

when start push button is pressed k1 (star)s energised ....so contact k1 changes to NC thus energising K2 (main)....so wen k2 is energised contacts of k2 changes its position thus de-energising k1....since k1 has an off delay timer k1t changes its position after a preset time thus energising k3(delta)..........

if there s an overload thn f2 will trip...n the cycle wil repeat once u press start button............

watever u ve given here s a difficult circuit for starters

search cr4 for a better circuit..........

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plckid
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#9
In reply to #8

Re: Control Circuit.

08/16/2010 8:21 AM

Thanks
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hentoyk
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Engineering Fields - Electrical Engineering - Hentoyk Philippines - Member - BRUTUS Saudi Arabia - Member - Brutus United Arab Emirates - Member - Brutus

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#10

Re: Control Circuit.

08/25/2010 12:46 AM

star-delta method experts called it " reduced voltage starting".

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Users who posted comments:

Anonymous Poster (1); hentoyk (1); lyn (2); plckid (3); PWSlack (2); SHAMITHGAMBHIR1 (1)

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