When a relay is rated for 24v DC / 10A can it handle anything upto 240Watts? say 12V 12A or 60V 4A ? some of the relay distributors have been saying this is possible however none of their datasheets show anything. I would like to hear from the experienced members on this. Can someone throw some light on this?
Or 960V at 250mA?
What do you think?
Contact ratings are not max power related, but rather specific max voltage and current ratings. You have to stay under both values no matter what the load power is.
The max voltage rating has to do with the contact spacing when open such that there is no 'flash over'. The max current rating is that which the contacts can handle without 'burning' material off the contacts.
On contact current ratings, if you look over enough relay spec sheets you will sometimes see examples where the contact current spec is higher if switching AC current Vs DC current. That is because the AC current is always passing through 0 amps/volts at 50/60 Hz and that helps extinguish the contact arc as the contacts open and close. However unless that is stated in the contact ratings you should always stay under whatever spec they do state.
That make sense?
Lefty
960V at 250mA?
well i have seen some 24v 10A relays being used for 60V 4A operations and they have been going good for over 4 months now but then I'm quite skeptical about the whole idea.
well i have seen some 24v 10A relays being used for 60V 4A operations and they have been going good for over 4 months now but then I'm quite skeptical about the whole idea.
And it might last for the life of the relay. It relates to how often the contacts are commanded to open and close, whether the contacts are sealed or open to atmospheric contaminants, etc, etc.
Specs are specs, and good engineering practice is to not exceed manufactures ratings and more often are over speced, that is buying 10 amp rated contacts and only using them at 5 amps in the actual application. It's considered a poor practice to utilize components at there maximum ratings.
Lefty