Contactor with 120v ac coil / need manual reset in case of power outage

Thread Starter

Lineout

Joined Nov 20, 2013
64
Is there a manual restart switch based on the power going low ?

I want to be sure a switch or button has to physically be pushed before
power can be re established.

The coil is 120 volts ac.

What are some good options to handle this ?

Thanks...
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
Yes this is the typical starter contactor device or circuit.
You place a N.O. aux contact on the contactor in parallel with the start P.B.
If you lose power the contactor drop out and opens the retaining contact.
You can also get starter boxes already configured this way.
Telemecanique wiring diagrams
Max.
 
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Thread Starter

Lineout

Joined Nov 20, 2013
64
Start, reset, engage N.O. P.B. or what ever you want to call it.
Max.
I'm not being smart, you said 'the' , not sure what you mean.

The pb is part of the aux or you assume I have one included ?

I don't understand this at all , I get contactors totally ,not how to
intergrate a an aux to make sure it doesn't come on when the power is out.

My pc won't handle a 100 page PDF download .
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
I want to be sure a switch or button has to physically be pushed before
power can be re established.

..
Your words, 'a switch or button' this is the N.O. P.B. I am referring to, you can also get self contained Starter boxes with start stop and the retaining contact or latch already configured.
Using separate items, you have to wire it your self, but it is minimal.
Max.
 

Thread Starter

Lineout

Joined Nov 20, 2013
64
Your words, 'a switch or button' this is the N.O. P.B. I am referring to, you can also get self contained Starter boxes with start stop and the retaining contact or latch already configured.
Using separate items, you have to wire it your self, but it is minimal.
Max.

Got it, but I don't understand the diagram in terms of applying it
to my contactor, the description of what it does is exactly what
I need.
This is a jard 17426 that I have right now, not sure I'll find an aux block that mates up.
I have several of these to hook up , I'd be better off if I could buy the
completed pkg so I could actually understand how it functions as one unit.
Is there a specific model that would be an all in one as you mentioned ?

Thanks....
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
That is rated a Definite Purpose Contactor intended for HVAC & heavy duty use etc.
You may not get a self contained unit with that rating, you would have to ask a local electrical supplier that stocks Square-D etc.
If it has no aux contact and no allowance for one, the alternative is a small auxilliary relay with a contact on it that picks up the coil, the relay would be wired exactly as per the PDF.
If it is HVAC etc, you most likely have a 12v/24v circuit there you could use for the small aux relay?
Max.
 

Thread Starter

Lineout

Joined Nov 20, 2013
64
That is rated a Definite Purpose Contactor intended for HVAC & heavy duty use etc.
You may not get a self contained unit with that rating, you would have to ask a local electrical supplier that stocks Square-D etc.
If it has no aux contact and no allowance for one, the alternative is a small auxilliary relay with a contact on it that picks up the coil, the relay would be wired exactly as per the PDF.
Max.
Ok...Thanks,

I'd have to see one put together to actually understand the whole picture.
I couldn't make enough sense of the pdf to go buying parts I think
would achieve what it appears is layed out.

Until I've seen it , I doubt I'll get the whole picture.

I might try a 555 in monostable with a P type mosfet or something and go around it another way.

Thanks!!
 

Thread Starter

Lineout

Joined Nov 20, 2013
64
That is rated a Definite Purpose Contactor intended for HVAC & heavy duty use etc.
You may not get a self contained unit with that rating, you would have to ask a local electrical supplier that stocks Square-D etc.
If it has no aux contact and no allowance for one, the alternative is a small auxilliary relay with a contact on it that picks up the coil, the relay would be wired exactly as per the PDF.
If it is HVAC etc, you most likely have a 12v/24v circuit there you could use for the small aux relay?
Max.
Yep, definite purpose , a bit of over kill for the equipment but very affordable.
I found some from China that were awesome , but shipping dates were way to far out.
 

inwo

Joined Nov 7, 2013
2,419
Could you explain the control circuit and load?

There may be other solutions.

The control relay solution suggested, may even be required, if the contactor is automatically controlled.

Or for certain load, from the same supply as control, two poles may be enough.
 

Thread Starter

Lineout

Joined Nov 20, 2013
64
Could you explain the control circuit and load?

There may be other solutions.

The control relay solution suggested, may even be required, if the contactor is automatically controlled.

Or for certain load, from the same supply as control, two poles may be enough.
A two pole contactor with a 120 volt coil / turns on a 220v table saw.

When the power goes out in the building , the coil will de energize, but when the power comes back on the coil will re energize and turn on the circuit.

I need a manual reset , so the coil cannot be energized unless someone
physically pushes a reset button/switch following any power outage.

I'm great with contactors, but have no clue how an auxillary contact block works.
 

inwo

Joined Nov 7, 2013
2,419
A two pole contactor with a 120 volt coil / turns on a 220v table saw.

When the power goes out in the building , the coil will de energize, but when the power comes back on the coil will re energize and turn on the circuit.

I need a manual reset , so the coil cannot be energized unless someone
physically pushes a reset button/switch following any power outage.

I'm great with contactors, but have no clue how an auxillary contact block works.
So is this what you have now?
Or do you use a transformer for the 120vac coil?
 

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