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Would you use a used contactor?

738 Views 10 Replies 8 Participants Last post by  cricketo
So I bought a "new" Kilovac EV200AAANA from Ebay. It's listed as new, the picture shows a new one. Total was ~$45, including about $13 for shipping.

When it arrives, it's clearly used. Scuffed, dirty, no hardware, cut wires.

So I initiated a return, and the seller is offering $10 off instead.

My gut reaction is "no," on principle. But the flip side is I only bought it as a secondary low-side contactor.

Thoughts?
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Those EV200As are everywhere. I think BWM used them?

Honestly, for how overbuilt they are, it's almost certainly fine.

But if you're worried, then make him take it back, and spend $29.99 at BatteryHookup and order one of their used ones instead that came out of working EVs.
 

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You would need a 4-wire meter to measure the exact sub-ohms of the contacts, but a quick check would be to energize the coil and just measure resistance across the contacts.

If it measured more than 1 Ohm then it might be damaged; if it is good then it will be under 1 ohm in the 0.1 region depending upon your meter.

For diy use it may not be as critical that it be in "perfectly new" condition. i never send anything back if they offer a discount to make it right, but that's just me.
 

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To put it in perspective, a 300 amp motor current means 60 electric room heaters' (the red glowing ones that dim your lights every time they kick on) worth of heat in the contacts of the contactor at 1ohm. 6 of those toasty suckers at 0.1 ohm...

99.999% chance you only have one way to check them, and that will not be pleasant or cheap. The equipment to check it out will buy you 10 contactors, at least.

Try to send it back, if not, sunk funds are irrelevant and buy a $30 replacement that's known good.
 

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Discussion Starter · #7 ·
You would need a 4-wire meter to measure the exact sub-ohms of the contacts, but a quick check would be to energize the coil and just measure resistance across the contacts.

If it measured more than 1 Ohm then it might be damaged; if it is good then it will be under 1 ohm in the 0.1 region depending upon your meter.

For diy use it may not be as critical that it be in "perfectly new" condition. i never send anything back if they offer a discount to make it right, but that's just me.
I have a good power supply and a meter, which will do the trick.
 

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Check for continuity between the main contacts without power applied to the coil wires. There shouldn't be continuity.
Then apply 12V to the coil wires, check for continuity between the main contacts. Now there should be continuity. If both conditions are met then the contactor is working. If either condition is not met then the contactor is not working. This will only confirm if the contactor is working. Not anything else.
For what it is worth the contactors from batteryhookup appear dusty too, they do have the connector on the coil wire. I haven't tried to find a matching connector yet. All the ones i have from BHU work.
later floyd
 

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I picked up about two dozen of these contactors from eBay, although I knew in advance that all units were 'lightly used'. I also spent $120 at Amazon for a AideTek VC480C milliohm meter. Most of the contactors measured <2 mOhm, but a few were 10-20 mOhm, and thus I labeled 'not for high current use' in my conversion projects.

I found this meter to be worth the investment, as I can also check all HV connections, jumpers, fuses, etc and minimize the chance of any failures due to poor connections.
 

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I would keep it even without the discount, but leave them a neutral feedback with the exact description of the issue. It is possible they didn't know it was used, as some sellers don't actually have inventory but rather have other entities supplying the goods, but it's still on them to make things right and not waste your time.
 
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