Rotary switch contact rating - Help please.

Thread Starter

paulktreg

Joined Jun 2, 2008
784
Hi

I have a rotary switch with a current carrying capacity of 5A non-switching, that's fair enough. It is however rated at 150mA switching @ 250V AC/DC. Could this switching current be safely increased at only 12V DC and by how much? If you took a proportional figure based on power then it would be a little over 3A at 12V DC but does it work that way? The actual data sheet of the switch in question is here but it doesn't give a 12V DC rating.

Any help appreciated.

Paul
 

eblc1388

Joined Nov 28, 2008
1,542
When the contact opens, there will be arcing and this limits the actual current value that can be safely switched.

I would adhere to the same 150mA current rating at 12V, but I think it would probably be OK to switch a bit more current like 300mA at 12V, but no higher.

This is nowhere near the 3A that you have calculated based on power. It does not work like this.
 

Thread Starter

paulktreg

Joined Jun 2, 2008
784
Thanks for that it's as I expected after looking at ratings on other switches and it looks like I'll have to find myself an heavy duty rotary!
 
Top