General Question About Switches

If a switch's data sheet says it's rated for 2A at 250V, can I assume that it is safe to push 4A at 125V through it, and 8A at 62.5V, and so on?

I am trying to pick a 3PDT switch for a project. If found one that is the right physical size but the data sheet says it's only rated for 2A at 250V. I will need it to carry between 3 - 4 A at 6V. Should I find another switch or should this one work?

Thanks.

No. Those are both separate ratings. It can take up to 2A and take up to 250V. It's not a power rating, so you can't convert it to power first.

Your assumption is not correct. The switch rating is the maximum voltage and current it can handle, it's not a power rating. You can not increase the current at a lower voltage. If you want 4A at 6V then you need a 4A switch.

Thanks for the quick responses. It didn't really make sense to me for it to be a power rating but I saw one data sheet that said:

Rating: 2A/250VAC; 5A/120VAC or 28VDC

I wasn't sure how to interpret the two different current ratings there.

vne147 said:

Thanks for the quick responses. It didn't really make sense to me for it to be a power rating but I saw one data sheet that said:

Rating: 2A/250VAC; 5A/120VAC or 28VDC

I wasn't sure how to interpret the two different current ratings there.

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In that case they are rating a higher current at a lower voltage since the rating is based, in part, on the arc damage to the contacts that occurs when the switch is opened under load. You can break a higher current at a lower voltage. But for this switch you would never want to break more than 5A, no matter how low the voltage.

crutschow said:

In that case they are rating a higher current at a lower voltage since the rating is based, in part, on the arc damage to the contacts that occurs when the switch is opened under load. You can break a higher current at a lower voltage. But for this switch you would never want to break more than 5A, no matter how low the voltage.

Click to expand...

Ahhh, OK that makes sense. Thanks. I'm glad I asked.