# Kilovac Contactors



## major (Apr 4, 2008)

69bug said:


> Hi,
> I managed to pick up a Kilovac Czonka III relay #EV200AAANA for $50 at a local sale.
> I see that EV Components and EV Parts sell them... link here.
> 
> ...


Good find. I think they're great. What's not to like? Smaller, lighter and sealed.


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## 69bug (Sep 17, 2009)

major said:


> Smaller, lighter and sealed.


My thoughts exactly. Seemed like one of those "too good to be true" scenarios. Just haven't seen much talk about them.

Thanks


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## Guest (Sep 29, 2009)

Love it. Small sealed, low power hold for the coil and the coil is 12 volt. Sweet. I have three. One is bad but only because one of the wires running into the epoxy on the top of the unit busted at the level of the epoxy. If I can dig a section of wire out and fix the wire and re-epoxy the contactor will be good for use again. Nothing but that darn wire. Be careful with the wires. Other than that, they are excellent. 

So far so good. 

Pete


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## martymcfly (Sep 10, 2008)

My Tyco Killovac got stuck. I couldn't turn off the power. I replaced it with a Albright. If the Albright gets stuck, you can pry it back open. I try to buy American when possible, but not in this case.


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## Tesseract (Sep 27, 2008)

martymcfly said:


> My Tyco Killovac got stuck. I couldn't turn off the power. I replaced it with a Albright. If the Albright gets stuck, you can pry it back open. I try to buy American when possible, but not in this case.



If your Tyco/Kilovac contactor got stuck it's probably because you don't do precharge properly (or at all?). Contactors pretty much always stick from closing into a short circuit.

We love the Tyco/Kilovac contactors. I've cut one open and it's good stuff on the inside, and even better in my opinion is that it is filled and sealed with the high-dielectric/spark-suppression gas, Sulfur Hexafluoride (SF6). This is extremely helpful in preventing arcing and damage when _interrupting_ a high current (like in the even of a catastrophic failure in your controller or wiring).


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## jaspersk (Jun 26, 2008)

martymcfly said:


> My Tyco Killovac got stuck. I couldn't turn off the power. I replaced it with a Albright. If the Albright gets stuck, you can pry it back open. I try to buy American when possible, but not in this case.


Wow! How much current do you run through there? As Tesseract suggested, did you have a short circuit? Seems to me that a lack of precharge wouldn't do but I could be wrong. Either way the rating on those contactors is really high so I am surprised you managed to weld it shut. That is a pretty scary scenario. I always thought the people that suggested dual contactors in case one welded shut were just being ultra conservative without any data to back up their concerns. Obviously, it sounds like two contactors are a smart plan.

I have both Albright and Kilovac. The Albright is used for reversing and the Kilovac is for the main contactor. I have had problems with both. 

You have to be very careful with the bolts on the Kilovac. I like to torque my electrical connections fairly tight (we all do right?) but I actually broke the head bolt right off. When I did it, I really didn't think I was putting that much torque on it. I am not sure what kind of metal that is but I am tempted to say it is a coated copper because it had the copper color once it snapped. That would explain why it snapped more easily than I expected. There is probably a torque spec with the relay that I ignored.  

The problem I had with the Albright is that while it was a reversing contactor, I had it as a low priority on my 'to do' list to wire up the reversing side and was using my transmission. I think those contactors like to be cycled on some frequency. The normally closed contact on the reversing side quit conducting. I took it apart and there wasn't really any residue on the bad contact that I didn't see on any of the good contacts but a little emory cloth and it was fixed.

All that said, intuitively, I like the Kilovac better probably because it is small, lightweight and cheap. Logically, the Albright is probably better because you can take it apart and clean it and troubleshoot it if you have any problems.


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## major (Apr 4, 2008)

jaspersk said:


> Seems to me that a lack of precharge wouldn't do but I could be wrong.


Hi jasper,

Without a precharge you get an arc as the contacts close. This can actually be a worse situation than an arc on opening. If the arc melts a bit of the contact surface and then the contacts are forced together, they can become stuck as the molten metal freezes. Whereas an arc on opening occurs as the contacts separate, so they are less likely to fuse together.

Regards,

major


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## 69bug (Sep 17, 2009)

Thanks for info.
I have a pre-charge resistor and diode that I got with my controller.

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