Maker Pro
Maker Pro

Safety Requirements for Switches



Jan 1, 1970
I'm trying to determine industry accepted practice for the use of
switches in electronic equipment. I may wish to have my equipment UL
certified eventually.

My question has to do with the voltage applied to the switch.

Switches are rated for the voltage that can be present across their
leads. If I have a 12V switch attached so that one lead is at 110V
and the other lead is at 120V, then the voltage across the switch is
within the switches specs -- however, the potential of the switch
above ground is quite high.

What I am trying to determine is what the acceptable voltage between
the switch leads and ground (the user) is.

There are many switches that have a dielectric rating of 250V. Does
this mean that I can use that switch in this manner?

Obviously the best solution would be to alter the design so that the
mean voltage is near ground. But in this case, I'd rather not do that
if I don't have to, since every penny counts, and I don't wish to add
any components. (I already flipped the polarity of the entire circuit
once to address a much more severe safety issue.)

Worst case, I can just leave the switch out, but I'd rather not do

I'm really looking for a response from someone who KNOWS the answer to
this question, not just a bunch of guesses... so if you want to reply
and give your oppinion, by all means do, but please say in your reply
that you don't know for sure.



Jan 1, 1970
This post has been crossposted to sci.engr.electrical.compliance.
It's more appropriate there. Please reply there.