Which contactor brand?

J

Thread Starter

JEIC

I need to select another brand of contactors, because the low cost units we have been using are not satisfactory. I am getting pricing on IEC units from Eaton, Allen-Bradley, Schneider/SquareD, and Siemens. After significant web searches looking for independent tests ranking the major brands, I have found nothing. My only recourse is to go to a place where people with experience have probably used several brands or, at least, can testify to the quality of a particular brand. What can you tell me? Are any of these brands superior, what do you prefer?
 
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Bob Peterson

I have used a number of different brands of IEC contactors. I have not noticed a lot of difference in performance.

I would ask in what way are the units you are using unsatisfactory and what brand are they?

IEC contactors require a little more in the way of thought in applying them than NEMA devices do. Any brand of IEC contactor you misapply will have the same problems.
 
S
I've used AB, ABB, Telemecanique, and others, and they all seem to work OK if properly selected. The key is to understand that a 50hp rating on an IEC contactor is far from the same thing as a 50hp rating on a NEMA contactor. Derate the IEC ones a size or two. they're still much cheaper and smaller than the NEMA unit you'd need, and they'll give very satisfactory service.
 
> I would ask in what way are the units you are using unsatisfactory and what brand are they?

The brand we were using was MEC Metasol. They were doing well for us until they were redesigned to comply with the IEC finger safe requirements. Since then the construction has been poor, particularly on the overloads. The cases sometimes separate while I am connecting them to the contactor, and I have had two motors ruined because the overloads did not trip. One of these units and another started on fire inside the panel.
 
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Curt Wuollet

From past experience, a lot of people know how to make relays. And those who don't have been largely weeded out years ago. So if your low cost units are failing, it might be time to consider that the application is faulty. That is the conditions that kill one brand of relay will very likely kill another.

Once you are talking about contactors, you are dealing with a pretty rudimentary device with very robust actuation and big contacts, often with some wipe built in. They are generally soft contacts so as to deform a bit and break oxides and the like. And they are very similar. I have very occasionally seen a bad contactor where a coil burned or a spring broke. But I've seen tons of burned contacts. And upon replacing them the new ones will soon fail too. But, you probably won't fix that with another brand. You fix it by finding out why they are burning and fixing that. Inductive loads are the usual culprit. You can keep replacing contacts or contactors or install suppression. I've increased life by an order of magnitude or more by installing suppressors whenever a contactor or relay fails before it should.

Regards
cww
 
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Curt Wuollet

Any of the majors probably won't fall apart. I've been using Fuji and Eaton, two lower cost brands and they seem fairly good mechanically.

Regards
cww
 
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James Ingraham

Contactors could be used as a perfect example of a commodity in an economics class. Eaton, Allen-Bradley, Schneider/SquareD, and Siemens are all perfectly fine. I have the most experience with A-B; never had a problem. I've used Siemens; they're fine. I've never actually used Schneider's contactors in the real world, but they seriously impressed me with their combination overload / reversing starter that has a tall-and-skinny format that matches their variable speed drive foot print. Neat stuff. This is yet another example of where I think what matters most is not the technical specs but your relationships with vendors (and customers, if you're selling equipment). Do you buy a bunch of A-B stuff? Stick with A-B. The US is a"nobody every got fired for buying Allen-Bradley" area; in Europe that would be Siemens. Do you want to be able just pull up a website and order five units on a credit card? Eaton via AutomationDirect.com.

Really, I don't think any of the brands you mentioned would disappoint.

-James Ingraham
Sage Automation, Inc.
 
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