So Why Doesn’t My Contactor Work?

[Seven-Delta-FortyOne]

Your original contactor had a 110-277 volt coil. It would not work off of low voltage DC.

The original contactor closed when the black wire was energized 120V and opened when the red wire was energized 120V.

You connected the black and red to the new coil. These wires will never have 120V between them unless you made other modifications.

Check voltage between black and white the red and white.

I did not modify it. I took what I believed to be 24vdc control wires from the relay and connected them to a1-a2.

 

[hillbilly1]

Found a picture of one that closely resembles yours, just can’t see the coil terminals on your picture, the side contacts appear to be auxiliary contacts. Couldn’t blow the picture up enough to make them out.

 

[Seven-Delta-FortyOne]

It’s either melted from the wrong voltage applied, or defective from the factory. The white bar should easily push in, and return out on its own. It is made to attach auxiliary contacts to, and activate those contacts when the coil is energized. Can you get a better picture of the contact block on the bottom? That should be the coil. Where the red and black wires are now, are power terminal screws for providing power to the control circuit off the line side. I will see if I can get a 360 picture of that contactor to be sure.

The white bar pushes in and retracts fine, it just didn’t close the contactor.

It does have 1 set of NO and NC auxiliary contacts on the bottom. Not using them.

 

[jim dungar]

So I found this on Platts website, and it seems to show that control wiring is 100-250vac.

That appears to be the Aux contact ratings.

We need to see the contactor coil itself.

 

[Seven-Delta-FortyOne]

 

[jim dungar]

I did not modify it. I took what I believed to be 24vdc control wires from the relay and connected them to a1-a2.

The Red Black and white wires from the control relay appear to get their power directly from the contacts in the Time Clock which looks like 120VAC.

 

[hillbilly1]

I did not modify it. I took what I believed to be 24vdc control wires from the relay and connected them to a1-a2.

Ahh! Thats it! The relay coil may be 24 vdc, but the contactor control voltage is probably 120 or 208. Use the N/O contact off the relay to drive the contactor coil.

 

[Seven-Delta-FortyOne]

That appears to be the Aux contact ratings.

We need to see the contactor coil itself.

This is the only other markings on the contactor.

 

[jim dungar]

It is possible the contactor mechanism is not assembled correctly. Either the coils is jamming something or the AUX contactor module on the side of the contactor is sticking. You should be able to push it in.

I see nothing in any picture that is provides or is powered by DC. most readily available information on relays is their contact ratings, but you need to find the coil rating.

 

[Seven-Delta-FortyOne]

The Red Black and white wires from the control relay appear to get their power directly from the contacts in the Time Clock which looks like 120VAC.

Yes input power to the control relay is 120, from the time clock.

 

[jim dungar]

Looks like nothing is connected to the coil terminals (block on side bottom that says A1 and A2)

The thing on the side is the 'holding circuit' contacts, not the coil.

 

[Seven-Delta-FortyOne]

It is possible the contactor mechanism is not assembled correctly. Either the coils is jamming something or the AUX contactor module on the side of the contactor is sticking. You should be able to push it in.

I see nothing in any picture that is provides or is powered by DC. most readily available information on relays is their contact ratings, but you need to find the coil rating.

That is exactly what I can’t find. I’m now on minute 35 on hold to ABB

 

[Strathead]

Most have built in clearing contacts, but there are still manufacturers that need a pulse kit. The cheap GE ones still do, I think ASCO makes them, but also carries the Siemens name too.

I disagree, most enclosed contactors are ordered with them but the predominate brands in my mind are Siemens, Asco (which is Schneider not Siemens) and Eaton. I have dealt with all three in the last year and for all of them clearing contacts and hand off auto switches are options available, not integral with the contactor itself. In fact with the old Asco the clearing contacts actually mounted to the contactor. At least the Eaton and Siemens it is a separate component inside the enclosure now.

 

[jim dungar]

This is the only other markings on the contactor.

The coil voltage should be on a sticker down where you put the red and black wires.

 

[Seven-Delta-FortyOne]

Ahh! Thats it! The relay coil may be 24 vdc, but the contactor control voltage is probably 120 or 208. Use the N/O contact off the relay to drive the contactor coil.

I was just going to eliminate the control relay as soon as I confirm that control voltage to the contactor is 120v.

 

[Strathead]

These require a two wire module.

Looks like the Siemens version.

 

[Seven-Delta-FortyOne]

The coil voltage should be on a sticker down where you put the red and black wires.

Absolutely nothing. I turned this contactor over and over before I installed it, searched for any spec sheet I could find, and I’m coming up empty.

 

[jim dungar]

I disagree, most enclosed contactors are ordered with them but the predominate brands in my mind are Siemens, Asco (which is Schneider not Siemens) and Eaton. I have dealt with all three in the last year and for all of them clearing contacts and hand off auto switches are options available, not integral with the contactor itself. In fact with the old Asco the clearing contacts actually mounted to the contactor. At least the Eaton and Siemens it is a separate component inside the enclosure now.

Yes this is true for many panelboard mounted main "lighting contactors". This replacement device appears to be a standard "power contactor" typically used for motor starting.

 

[hillbilly1]

I disagree, most enclosed contactors are ordered with them but the predominate brands in my mind are Siemens, Asco (which is Schneider not Siemens) and Eaton. I have dealt with all three in the last year and for all of them clearing contacts and hand off auto switches are options available, not integral with the contactor itself. In fact with the old Asco the clearing contacts actually mounted to the contactor. At least the Eaton and Siemens it is a separate component inside the enclosure now.

The only ones I have used in the past 35 years that didn’t have clearing contacts, was the one I pictured. I have used GE, Square D, Siemens and ASCO. ASCO has a model that looks like a heat sink with a coil in the center. Siemens, GE and Square D all put their name on it. Those have a single coil.

 

[hillbilly1]

Looks like the Siemens version.

GE also puts their name on them. Home Depot used them on their landscape supplies stores, as well as Publix uses the electrically held version for the emergency lighting. They can easily be changed from N/O to N/C by flipping the contact block. I think Square D has the only other one that is field convertible. But is a little more involved.