# Finding a 72VDC switch



## flashedarling (Jun 30, 2008)

I'm in need of a main disconnect switch which is rated for 72VDC and a max contact current of 250A but I can't seem to find this anywhere. Where can I find a switch that can handle this kind of load?


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## Jimdear2 (Oct 12, 2008)

flashedarling,

Try this link.

http://www.curtisinst.com/index.cfm?fuseaction=cDatasheets.dspListDS&CatID=7

Look at the ED and SD data sheets The SD has to be ordered from England (Still waiting for mine). The ED250 looks like it will fit your bill, I priced it at Global Products at $85.00 plus S and H.

Albright is really good stuff. 

There are other alternatives like circuit breakers. Check through the threads for links.

Hope this helps
Jim


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## Twilly (Jan 22, 2008)

Ive had good luck with these guys...


http://www.electricvehiclesusa.com/category_s/168.htm


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## grayballs (Aug 27, 2008)

You can find these on eBay,,,, $50 - $75 depending on how many you order. I've used them in the past, just ordered 5 more

http://www.wesgarde.com/newproduct_Kilivac.shtml


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## Jimdear2 (Oct 12, 2008)

grayballs said:


> You can find these on eBay,,,, $50 - $75 depending on how many you order. I've used them in the past, just ordered 5 more
> 
> http://www.wesgarde.com/newproduct_Kilivac.shtml


Yes the Kilovac is a very nice contactor I like them myself. I think that flashedarling was looking for a disconnect switch though.

Or maybe we just have a terminology problem. 

Flash, are you looking for a switch that you *manually* operate to disconnect the tracton battery pack from everything. I.E. emergency disconnect or overnight shutdown

Or are you looking for an *electrically* operated switch, usually controlled by the key switch and/ot the throttle pot box that isolates the power from the controller.

If you want a *manualy* operated switch go with a circuit breaker or disconnect like the Albright.

If you need an *electrically* operated switch the Kilovac is one of many good ones.

Hope this helps,
Jim


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## flashedarling (Jun 30, 2008)

You are correct, I am looking for a *manually* controlled switch. I already have a contactor for main power. I also have a relay powered pre-charge circuit. I am looking for a switch to completely cut off power to the contactor and relay.


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## Jimdear2 (Oct 12, 2008)

flashedarling said:


> You are correct, I am looking for a *manually* controlled switch. I already have a contactor for main power. I also have a relay powered pre-charge circuit. I am looking for a switch to completely cut off power to the contactor and relay.


 
Then the Albright is a good one (also it can be very professional looking).  The circuit breakers work well also (kind of kludgy looking though).

The cheapest way of course is an Anderson Connector that you just pull apart.  At least half of the EV's I've looked at have used this method as a disconnect. Many use a cable or mechanical linkage to remotely operate as an emergency disconnect. I'v even seen a few that even remotely re-connect through linkage.

I may be preaching to the converted here, but just make sure that whatever you select can survive the arc that will occure with a full power disconnect without welding itself. 

I've been reading about a lot of controllers that fail at full power to give a motor runaway.  You need something that resides between the battery and the rest of the system within the drivers reach to shut everything down FOR SURE.

Using the disconnect for shuting down the system for maintenance, charging, or storage is secondary.

Hope this helps,
Jim


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