b3ngy
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| posted on 1/5/13 at 06:09 AM |
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Toggle switch amp ratings
Electrics really isn't my strong point so was hoping someone could give me some advice on what size amp rating i would need for some toggle
switches for my dash.
I'm going to be redesigning my dash layout so will have toggle switches for everything, lights,indicators,fog,hazards etc etc.
Do they need to be all of the same rating or different ratings depending on the circuit??
Thanks for any help.
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designer
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| posted on 1/5/13 at 07:28 AM |
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Just buy a good quality switch, with a the largest amperage, for them all.
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snapper
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| posted on 1/5/13 at 07:30 AM |
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It would be much better practise to use relays that way all the amperage is dealt with away from the switches
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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deezee
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| posted on 1/5/13 at 07:33 AM |
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I assume most will be switching relays, so the amp rating needn't be too high. The toggle switches I have in mine are 10A 240v rated? so I
would assume when down at 12v they are more than meaty enough. Too be honest you want them reasonably large, so they have nice chunky connectors on
the back, which makes wiring easier.
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BenB
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| posted on 1/5/13 at 07:45 AM |
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A 10A 240v switch is usually still only good for 10A at 12v. High voltages might jump gaps better than low voltages but it's current that makes
things get toasty warm and burn out.
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b3ngy
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| posted on 1/5/13 at 07:51 AM |
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My dash is already up and running using sierra stalks. Is there any need to consider using relays?? All I want to do is get rid off the sierra stalks
and replace them with toggle switches.
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rx7locost
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| posted on 1/5/13 at 01:34 PM |
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quote:
A 10A 240v switch is usually still only good for 10A at 12v
Maybe, depending on the switch's construction. The DC capability can be as high as 100% of the AC rating or as low as 5% of the AC rating. Most
switches must be de-rated for DC use. Unless it is marked for DC, you will never really know how much for sure. The problem is not usually the current
carrying capability but the current breaking capability when turning the switch off.
It is best to use DC rated switches.
Here is a simple video showing the difference between breaking DC vs AC current.
http://www.youtube.com/watch?v=Zez2r1RPpWY
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snapper
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| posted on 1/5/13 at 03:13 PM |
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If your Sierra switches have a square hazard warning button they don't require relays but your switches might
If your Sierra switches have a round hazard warning button there should be relays in the wiring already but you should check
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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b3ngy
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| posted on 4/5/13 at 08:20 AM |
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thanks for the help guys, i'll look in to it.
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v8kid
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| posted on 4/5/13 at 08:42 AM |
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quote:
Originally posted by rx7locost
quote:
A 10A 240v switch is usually still only good for 10A at 12v
Maybe, depending on the switch's construction. The DC capability can be as high as 100% of the AC rating or as low as 5% of the AC rating. Most
switches must be de-rated for DC use. Unless it is marked for DC, you will never really know how much for sure. The problem is not usually the current
carrying capability but the current breaking capability when turning the switch off.
It is best to use DC rated switches.
Here is a simple video showing the difference between breaking DC vs AC current.
http://www.youtube.com/watch?v=Zez2r1RPpWY
Nice video
Cheers!
You'd be surprised how quickly the sales people at B&Q try and assist you after ignoring you for the past 15 minutes when you try and start a
chainsaw
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snowy2
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| posted on 8/5/13 at 06:51 AM |
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at 12v for automotive use the amp rating is effectively the same on the switch and as a rough rule of thumb the amp rating of switches will be the
same rating ac/dc and dc for all automotive circuits. the video is very interesting however the requirement of the switched load is quite high (3-4Kw
= 18A at 220v) or at 12v =330A
its the same principle your mig welders work on.
so long as the switches have a rating the same or better yet higher than the circuit to be switched you'll be fine. but the switches will either
all be big numb switches or all different to suit differing loads. as it was said in the post earlier use relays to handle the current loads (very
very easy to fit) and get your self a matching set of low amperage switches to do the switching.
sometimes you are the pigeon, most of the time the statue.
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