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Wiring a D.O.L starter (Read 92471 times)
superunknown
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Wiring a D.O.L starter
Sep 2nd, 2007, 9:53am
 
Hi, this is my first time here.

I hope somebody might be able to advise me how to wire a single phase dol starter switch with Thermal Overload Relay?

I have searched online for a diagram but am yet to find anything that makes sense to me.

Thank you Smiley

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Lectrician
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Re: Wiring a D.O.L starter
Reply #1 - Sep 2nd, 2007, 12:58pm
 
They generally come with some instructions - have you got one that has none?

First of all, as its single phase, make sure you get a 240v coil version.

Quick pic below:

...

The coil is on terminals A1 and A2, and is not polarity important.

There is a hold on contact (usually) hidden behind the green push button, or the green push button actually presses this hidden contact in.

If you want additional start and stop buttons, the green start button is wired in parallel across the current green button, and the red stop buttons are wired in series after the current stop button.  You can simply run three cores to a remote start/stop station, as the bottom of the green and top of the red are obviously commoned up.

There will usually also be a set of contacts which close if the overload trips, and these are used to signal to a red 'tripped' light or alarm etc.

You will notice that the third pole of the contactor which would be the htird phase in a three phase setup is being used with a looped neutral - this is considered good practice as the three poles are all monitored for overcurrent.
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« Last Edit: Sep 2nd, 2007, 1:15pm by Lectrician »  

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superunknown
Re: Wiring a D.O.L starter
Reply #2 - Sep 2nd, 2007, 1:41pm
 
Thank you so much for your help, I didn't have any wiring instructions with it and not being an electrician found it very confusing.

Still a little un-sure to be honest.

This is what I have...

...


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Re: Wiring a D.O.L starter
Reply #3 - Sep 2nd, 2007, 2:04pm
 
All the control links look to be inplace already.  Leave them in the terminals they are in.  You may need to open the terminal to add your supply wires, so make sure you leave the control wire in that same terminal aswell.

Supply Live to L1

Supply Neutral to L2

Motor Live to T1

Motor Neutral to T3

Link T2 to L3 with a link of wire the same size as the supply and motor wire.

My diagram does depict your starter very well.

The four terminals at the bottom of the overload part (95 and 97 being the central two) are for the remote indicators I mentioned above, and will not be used in your case.
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« Last Edit: Sep 2nd, 2007, 2:05pm by Lectrician »  

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superunknown
Re: Wiring a D.O.L starter
Reply #4 - Sep 2nd, 2007, 2:06pm
 
Thank you very much for all your help.  That solves all my problems with it.



Steve
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Re: Wiring a D.O.L starter
Reply #5 - Sep 2nd, 2007, 2:07pm
 
No problems, I ammended my post above slightly as you where replying, so you may want to re-read it!
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Mathieu Davy
Re: Wiring a D.O.L starter
Reply #6 - Jul 2nd, 2009, 11:15am
 
Hello,

Thanks for this useful info.

Can you also explain how to wire a contactor + Overload relay for a 3 phases motor?
The constraint are:
- One single push button with a light bulb for start and stop
- No external 24V supply
I guess I have to go for a contactor with a 220V coil in that case. Is that correct?

Thank you for your help

Mathieu
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Zambezi
Re: Wiring a D.O.L starter
Reply #7 - Jul 2nd, 2009, 11:19am
 
230V contactor coil if you have a neutral locally if not then a 415V coil, which you can feed from the 3 phase supply. Wired in pretty much the same way as the single phase DOL
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Mathieu Davy
Re: Wiring a D.O.L starter
Reply #8 - Jul 2nd, 2009, 4:11pm
 
Hi Zambezi,

Thks for your reply.

Yes I do have a neutral locally so i'll get the 230V contactor coil.

Actually, for the control circuit, due to space and homogeneity constraints on the control panel, I would like to use a single illuminated push button for both start and stop and not one for start and one for Stop.
Is it feasible ?

Mathieu
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« Last Edit: Jul 2nd, 2009, 4:15pm by mathieudavy »  
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Zambezi
Re: Wiring a D.O.L starter
Reply #9 - Jul 2nd, 2009, 9:24pm
 
I am not sure, I don't know of a single switch that can perform both functions (I don't know how you would wire it unless you used a latching switch but I am not sure if this is allowed?).
I have seen a module that has a start and stop button on it, I will see if I can find one....
http://cgi.ebay.co.uk/Box-of-10-x-Stop-Start-Push-Button-contact-blocks_W0QQitem...

You may also need to fit an emergency stop button, to kill the machine if something goes wrong.
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Re: Wiring a D.O.L starter
Reply #10 - Jul 3rd, 2009, 5:13pm
 
You could, but you would need to use an impulse relay switched via your switch, and then switch the contactor with the impulse relay.

Not ideal though - Green is start and Red is stop.  It could confuse people.
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Mathieu Davy
Re: Wiring a D.O.L starter
Reply #11 - Jul 9th, 2009, 10:52am
 
Thanks,
I've decided to keep it simple and I choose the classical start / stop with 2 push buttons.

Now I have another challenge.
I have one machine with 5 contactors (all 3 phases) as follow:
Contactor 1 for motor 1
Contactor 2 for motor 2
Contactors 3, 4 and 5 for motor 3 wired as Star Delta.
(3 for star, 4 for delta, 5 for main with overload relay)

The contactors are interlocked as follow:
Motor 2 won't start unless motor 1 is running.
Motor 3 won't start unless motor 1 and 2 are running.
if Motor 1 stops, then Motors 2 and 3 will stop.
if Motor 2 stops, then Motor 3 will stop.

I would like to remove all the interlockings and be able to start / stop any motor independently.
But I don't have the electrical drawings and the wires are quite difficult to chase.

If you don't have enough info to help, could you please explain me how the interlocking is usually done.

Thanks for your help
Mathieu
Singapore
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Zambezi
Re: Wiring a D.O.L starter
Reply #12 - Jul 9th, 2009, 12:13pm
 
I would not want to even start trying to advise on something as complicated as this on a forum. Since you are in Singapore I won't be able to pop over to have a look.

Interlocks can be done a number of ways, though normally open or closed contacts on the contactors/relays or within the switches or push buttons. Some of the interlocks will have to stay in place for the star delta starter to work properly, the same applies to the emergency stop circuit.

As a matter of interest, what machine are you trying to modify? I am guessing they fitted the interlocks for a reason, so I am not sure it would be a good idea to remove them?

Sorry I can't be of much more help.
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« Last Edit: Jul 9th, 2009, 12:15pm by zambezi »  
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Mathieu Davy
Re: Wiring a D.O.L starter
Reply #13 - Jul 9th, 2009, 3:49pm
 
The machine I want to modify is a (big) paper shredder.

The interlocks are design to prevent the main shredder to be operated while the discharge conveyor does not work.
It is not convenient for my operations as I want to be able to "pause" the discharge conveyor to exchange the discharge bag or bin when it is full without stopping the whole machine.

Regarding the emergency stop, I already plan to put an Emergency push button with 3 independant NC contacts inside so it will stop the 3 motors.

To add a little more fun, the contactor are not wired in the ways I am familiar with. The whole panel as no neutral point. So there is a transfomer that will take 2 phases at 430V to reduce to 230V. These 2 phases are then used to energize the contactor coils.

One of my option would be to get a neutral point in there (actually I have already done that for another uasage) and to rewire completely the contactors.

If you have any other suggestion...

Thanks
Mathieu
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Goodsparks
Re: Wiring a D.O.L starter
Reply #14 - Jul 10th, 2009, 2:21pm
 
It does all sound do-able... but I don't think modification of a machine like that, outside of the manufacturers guidance (and product safety approvals) is something that you should be considering yourself. It's deffinately outside of the scope of the advice given on this forum.

I've got a bloody great Schlecher shredder here at work - exactly the sort of thing you've described. The cutting rollers will chop through whole lever-arch files, pairs of scissors, video cassetes and anything else that gets in their way. That coupled with the ram which compresses the shredded paper pretty- much means that anyone or any part of anyone that got in the way, wouldn't stand much of a chance.
I'm not sure who the Singapore equivalent of the HSE is, but I wouldn't fancy having to explain my DIY modifications to them in the event of an accident.

Paul
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« Last Edit: Jul 10th, 2009, 2:22pm by Goodsparks »  
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marklefty
Re: Wiring a D.O.L starter
Reply #15 - Jul 29th, 2009, 8:53pm
 
I have been trying to fit two on / off switches to my wood turning lathe and am struggling I understand the wiring diagram above but not quite sure for the remote switches.
In the overload I have 98 and 97 on the NO side and 95 and 96 on the NC side there is a wire in 96 from the on button

Many thanks in advance

Mark
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Re: Wiring a D.O.L starter
Reply #16 - Jul 30th, 2009, 3:14pm
 
The NC 96 and 95 are your stop button and also open circuit if the overload operated.

If you want more stop buttons, place NC buttons in SERIES with the NC stop contact, so remove the cable from 96, take this to a new NC switch.  Take a cable from the new NC switch back to terminal 96.

To add extra start buttons, you need NO buttons, and these are placed in parallel across the current start button which is usually part of the contactor it self, but there will be terminals - one will be the same terminal as you terminal 96 onthe stop button.

You only need 3 cores between the contactor and a remote start/stop station, as terminal 96 is common to both the start and stop.

See below:
DOL Starter with remote start/stop   

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« Last Edit: Jul 30th, 2009, 3:21pm by Lectrician »  

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