# DC emergency kill switch

**URL:** <https://community.electricforum.com/t/dc-emergency-kill-switch/753>\
**Category:** Conversion Kits\
**Created:** [June 19, 2008, 11:26pm UTC](https://community.electricforum.com/t/dc-emergency-kill-switch/753 "2008-06-19T23:26:30Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![sfsherrill](https://avatars.discourse-cdn.com/v4/letter/s/9fc348/32.png) [@sfsherrill](https://community.electricforum.com/u/sfsherrill)\
**Post date:** [June 19, 2008, 11:26pm UTC](https://community.electricforum.com/t/dc-emergency-kill-switch/753/1 "2008-06-19T23:26:30Z")

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I am converting a 1969 VW bug into a 72 volt, DC EV. I need a kill switch that I can mount near the dash that I can smack if I get into an emergency. I am looking for one with a large mushroom type button. I’m thinking it should be about 500 ampere. Does anyone know where I might find one?  
Steve [sfsherrill@earthlink.net](mailto:sfsherrill@earthlink.net)

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**Author:** ![dtbaker](https://avatars.discourse-cdn.com/v4/letter/d/7bcc69/32.png) [@dtbaker](https://community.electricforum.com/u/dtbaker)\
**Post date:** [June 20, 2008, 4:26pm UTC](https://community.electricforum.com/t/dc-emergency-kill-switch/753/2 "2008-06-20T16:26:35Z")

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I dunno about mushroom type, but there are some at [http://www.kta-ev.com/catalog.html](http://www.kta-ev.com/catalog.html) or probably any big electric supply place.

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**Author:** ![new\_dawn](https://avatars.discourse-cdn.com/v4/letter/n/ad7895/32.png) [@new\_dawn](https://community.electricforum.com/u/new_dawn)\
**Post date:** [June 28, 2008, 5:46pm UTC](https://community.electricforum.com/t/dc-emergency-kill-switch/753/3 "2008-06-28T17:46:36Z")

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I used a inertia switch for emergency’s coupled with a fuse on the hot side of the batteries 144 volt positive. the inertia is tied to my contactor’s and key, basically everything on the 12 volt side, effectively killing the car in case of a accident. The fuse is in case of a high voltage failure I used a 400 amp fast blow fuse it cost about 50 dollars and the inertia switch was bought at the ford dealer for about 10 dollars.

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**Author:** ![frodus](https://avatars.discourse-cdn.com/v4/letter/f/e95f7d/32.png) [@frodus](https://community.electricforum.com/u/frodus)\
**Post date:** [June 30, 2008, 9:42am UTC](https://community.electricforum.com/t/dc-emergency-kill-switch/753/4 "2008-06-30T09:42:56Z")

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I know that the White Zombie has a large fuse holder (industrial) that has fuse assembly/handle that pulls the fuse. Essentially he put a large piece of conducting metal in there (or a high current fuse) and just pulls it when he needs.

500A mushroom is going to be huge, and expensive.

Why not use an inertial switch and a kill switch inline with the contactor power supply? you’ve already GOT the emergency kill.

If you’ve got a precharge resistor, the contactor will likely NEVER weld shut, and since its spring loaded, if power drops, it WILL open up.