[ausev] switching the mainline power

[Chris Robison]

What's the size of the EV?  What voltage and amperage are you talking about?

In a typical EV (say, 600A, 120V), the contactor is bulky and noisy for a
reason.  To actuate a keyswitch with your hands that's capable of carrying
that kind of current and safely breaking far more, you'd have a keyswitch
with enough spring pressure to risk breaking or bending the key.

Another problem is that this would imply having high voltage inside the
passenger compartment.  This is generally considered a Bad Idea.  Electro
Automotive breaks this rule with their kits, but the switch they use is a
huge Heinemann breaker, with a very large plastic toggle. It's mounted in
an area that's in the dash between the seats, a bit safer than a keyswitch
in a steering column above your lap.  And again, the thing is very big.  I
don't think I've ever seen a keyswitch that has terminals for 2/0 cable.

Far better to look for a contactor with a coil economizer, to reduce the
current drawn while closed.  Some controllers even feature separate
pull-in and holding voltages on their contactor outputs, for the same
reason.

  --chris




On Tue, November 7, 2006 5:45 pm, MLAB said:
> Does anyone know of key switches that can be used to switch the main
> power line on an EV?  I mean something that can handle big DC volts and
> fairly high current?  I know I can find relays that will do this, but
> they require their own power.  I am looking for something can just be
> manually switched and locked.  Any tips?
>
> If it is necessary to clarify, I am not looking to switch the thing on
> and off while the amps are flowing, but something that can handle having
> the current pass through it when it is on.
>
> --
> Mike Librik, LCI #929
> Easy Street Recumbents
> (512) 453-0438
> 45th and Red River Streets, thereabouts
> Central Austin
> info at easystreetrecumbents.com
> www.easystreetrecumbents.com
> www.urbancycling.com
>
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