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Does anyone know, or can tell me please, what's the link between amps and volts ? That is, if you have a switch rated at 25A at 240V AC, what would it be rated at for 12V DC?

Ideally I want a change over switch to run either one of two items at 100A 12V DC, what would this be at mains voltage ? This would be switched before becoming live so therefore no arcing.

100A at 12 DC is a ton of juice . You aren't going to find a simple toggle switch that will handle that for more than a few throws under load. What specifically are you trying to switch over?

Front or rear winch from one control switch. Control switch will operate solenoid pack (got these) and changeover switch will then select either F or R winch

wotcha buildin rodders.....winch challenge or argo?

sunndog wrote:wotcha buildin rodders.....winch challenge or argo?

Just modding the Argo, got the body band made and on. Got all the internal space frame done complete with winch mounts. Got the front winch on and just fitting the rear. Want to work either winch from dash mounted control instead of wander leads everywhere.
Roll cage, windscreen and hood to make and fit then it's finished. Just as well, got Argo number three on the trailer waiting to be started We might put something trick in that and see how fast we can get one to go Suzuki swift engine is supposed to be an easy fit under the bonnet but my son wants to put something bigger in the back (so it lands front up)

If the switch is only going to control the relay(s) then any 12V DC 10 amp switch will do the job OK.

Cheers

Bruce

rodp wrote:Does anyone know, or can tell me please, what's the link between amps and volts ? That is, if you have a switch rated at 25A at 240V AC, what would it be rated at for 12V DC?

Ideally I want a change over switch to run either one of two items at 100A 12V DC, what would this be at mains voltage ? This would be switched before becoming live so therefore no arcing.

If it's switch dead your ok with the ac rating, once you get past a couple of amp's switching dc off becomes a problem due to arcing.

If I wanted a switch rated to 100 amp I'd fit one at least 120 amps just to be sure.

rodp wrote:Front or rear winch from one control switch. Control switch will operate solenoid pack (got these) and changeover switch will then select either F or R winch

I would recommend a Marine, battery bank switch.

http://www.basspro.com/BEP-Marine-Batte ... uct/97350/
...sorry, state side link. But you can at least get an idea of what I am talking about.

The switch is intended to run one high amperage trolling motor on either, battery #1, battery #2, both batteries, or "Off". These will handle 250 amps +. You would just have to wire it up backwards. Put your Argo battery where the output the trolling motor would be. Battery #1, and Battery #2, would be front or rear winch. "Both", would essentially allow you to power up both winches simultaneously and rip the Argo in half.

Thanks Bruce but it's got to pass the full 100 amps !!


Marky, yep the switch will be dead when operated. I need a double pole 3 postion change over / reversing switch. Switch will be dash mounted and operate as, front winch only, off , rear winch only. Once the required winch is selected then the solenoid / relay box will operate the selected winch.
Got to be double pole as obviously polarity is reversed to spool in /out so can't use chassis return. !00 amps is absolute maximim, that would be on a full drum at stall speed. It will never reach that, as a snatch block would be used well before that sort of load is imposed, so reckon on about 40 to 50 amps. I will still go for the 100 amp rating though as you can't be too careful.

Thanks men.

As phoenix says if wired correctly the switch will only need to be rated for the relay coil current.