DOL Stop Start Contactor/overload

[piratebillybob]

hi

ive searched for two days now and i still cant find a definitive method to wire a single phase contactor/overload dol.

The whole normally open/normally closed coil thing with the coil/relay and all the numbers on the contactors just boggles my mind.

i know once its explained itll simple but if anyone could point the way to an idiots guide ild be forever grateful

Im guessing a1 a2 are the coil. 21 & 22 or 95 & 96 are NC. 13 & 14 NO. L1 L2 L3 are for the phases.

Many thanks if you can help

 

[Des 56]

I'm not sure if its a rough outline of the operation you want,if so,here is a sketchy, and may I say, not too detailed general operation
Forgive me if this is not whats being asked

Its a glorified electrically operated set of switches which will be either energised or de energised
Once its operated.it needs to stay on

The contactor coil is energised ( it becomes a magnet) via the use of a start button which is wired in series with the coil
The coil circuit is complete when this is pressed
The magnetised coil draws the contactor closed, resulting in the load and auxillary contacts ( switches) operating
The coil gets it supply from the supply end
You can have a 230 volt coil or it can be a 400 volt coil

Press the start button and the coil energises/magnetises
In order for it to stay energised, when you take your finger off the start button, there is a link made that keeps it energised (it bridges the start button)this bridge is made when the coil drags the contactor closed ( a set of contacts for that bridge of the coil circuit closes)it takes over from your finger

You also need a switch that will de energise the coil when required,so a stop button is wired in series with the coil circuit, so that when its pressed, the coil de energises, it stays de energised because the bridging link (closed when energised) will have been dis connected

If need be,there can be external switches in series with the coil to also de energise,such as limit switches and external emergency stops

The contactors, when energised, have sets of switches that can be used as need be

Try looking at a diagram and use a continuity tester.follow the circuits with the coil open and again when you physically close it

 

[Knobhead]

Three questions first

Are you using a 3 phase contactor / overload for a single phase motor?
Can you follow a single line drawing or has it got to be a picture done in block form?
What make is the contactor?

 

[ackbarthestar]

There's loads of info regarding DOLs Try a google to find the model and manufacturer

 

[silva.foxx]

ive searched for two days now and i still cant find a definitive method to wire a single phase contactor/overload dol.

Im guessing a1 a2 are the coil. 21 & 22 or 95 & 96 are NC. 13 & 14 NO. L1 L2 L3 are for the phases.

Two whole days?

Here, have this Bible... http://www.moeller.net/binary/schabu/sb0801g.pdf

Other relative topics http://www.electriciansforums.net/c...-phase-contactor-3-phase-coil.html#post226368

...

 

[wade88]

Hello pal,

I was having a similar issue back over christmas, not having much exp of contactors at the time i consulted the oracles on here and managed to get my act together with it. After wiring the bugger up, i then drew this diagram to help me remember for next time. i must point our however, this may have ABSOLUTELY NOTHING to do with your arrangement, as other posters have already mentioned, we dont know a great deal about what your trying to achieve here, coil voltage, motor power etc. So this may be of no use to you what so ever, but it wont hurt for you to take a look. its very simple...because i work best that way . This does have a safety cut out switch included.

 

[piratebillybob]

this is the kind of thing i was thinking of.

with single phase going through the normally closed stop button into the normally open start. Someone closes the start button it sends current to the coil which brings the contacts in and the motor starts.

And then things get fuzzy. Even though the start button re-opens as its normally open the coil stays energized until someone presses the stop?

does the L3 - T3 route do anything?

Many thanks if you could clear it up

 

[telectrix]

it stays energised because yo have a "slave" contactor in parallel with the start button. once the coil is energised by pressiung the start button, the slave contacts hold the coil energised untill the coil supply is interrupted by prfessing the stop button.

 

[piratebillybob]

thanks for the reply

so the start button kinda pushes some slave contacts into place and they go to the coil, and theyre whats connected to the stop button in series?

 

[telectrix]

yep, think it's 13 and 14 on the diagram. when the contactor pulls in, these contacts parallel the start button, so the coil " thinks " that the start button is permanently pressed.

 

[Engineer54]

Oh My God!!!!

 

[Knobhead]

After all these years ! ! ! !

View attachment 8277

 

[ackbarthestar]

thanks for the reply

so the start button kinda pushes some slave contacts into place and they go to the coil, and theyre whats connected to the stop button in series?

The manual stops are connected in series, either between 13-A2 or 96-14 (your diagram) you cannot rely just on the overload and the isolator to stop the machine.

 

[ackbarthestar]

Oh My God!!!!

Look Tiger,..... You try to learn about Motor starters without somebody well and truely up your rear giving you one when you make the wrong connections:wink_smile:

There are many young sparkies out there who don't have the luxury of an indentured apprenticeship

 

[Engineer54]

Look Tiger,..... You try to learn about Motor starters without somebody well and truely up your rear giving you one when you make the wrong connections:wink_smile:

There are many young sparkies out there who don't have the luxury of an indentured apprenticeship

Errrr!! you really shouldn't be learning about motor starters or anything else come to that, while your working on the actualjob, ...now should you?? Further, i've looked around on the internet, and found a whole heap of site's of manufacturers, training area's and general knowledge sites that showed you quite simply and clearly, control circuits for both 3 phase and single phase. You just cannot get simpler than a start /stop DOL motor starter control connection.

But your right about apprenticeships, ....and there i agree wholeheartedly that it's a crying shame that they are now so few and far between, and it sure does show!!