Relay contact rating

to switch 16V AC max with 5A max current (i.e 80VA), Can I use this relay? or max current is 2A only irrespective of voltage and AC or DC.

But. If this is for audio as you imply, then would you ever really see this current for any significant length of time?

Phil Allison will know.

Cheers

required to switch 16V AC max with 5A max current (i.e 80VA), Can I use this relay? or max current is 2A only irrespective of voltage and AC or DC.

Yes..it is for Audio and peak current will only be for short bursts.

Yes. Never exceed the current rating regardless of the Watts (same as VA on DC, VA times Power Factor on AC).

required to switch 16V AC max with 5A max current (i.e 80VA), Can I use this relay? or max current is 2A only irrespective of voltage and AC or DC.

In my opinion, it'll be fine as long as there's no safety hazard in the event of the relay contacts not opening, but I wouldn't do it commercially. It's outside the specification of the relay so there's no comeback if someone dies in a raging inferno.

Cheers

Switching will very rarely be simultaneous with the full 16 volts and 5 mps - plus with audio signals, arcing upon opening is much less than with

The average current passed by the contacts with audio program is gonna be well less than 2 amps.

Have you ever seen the puny pushbutton switches used in most hi-fi amps for speaker switching?

.... Phil

"Syd Rumpo"

... Phil :-)

snipped-for-privacy@gmail.com schrieb:

to switch 16V AC max with 5A max current (i.e 80VA), Can I use this relay? or max current is 2A only irrespective of voltage and AC or DC.

Hello,

if you switch DC, the maximum current is 2 A and the maximum voltage is

Bye

required to switch 16V AC max with 5A max current (i.e 80VA), Can I use this relay? or max current is 2A only irrespective of voltage and AC or DC.

"John Fields"

The 2A figure is the relay's rated switching capacity under at max conditions with a stated number of cycles.

When closed, the contacts can handle far more.

Relays and small toggle switches are lousy at switching DC of any size.

The use of speaker relays in audio amps is a non trivial subject with which I am very familiar.

And you are not.

.... Phil

But Phil is all mouth >:-} ...Jim Thompson

If horses didn't s*it, they would be almost as big of an ass as you are.

Usually called "carry current" or "carrying current" ratings.

Relay makers don't seem to be very bold in such ratings- sometimes they are just the same as the switching ratings.

I had an old Motorola app note that claimed some "well designed" 5A relays could carry 50A.

These days, they'd cr*p on the engineers for wasting so much valuable material rather than call the product well designed.

Best regards, Spehro Pefhany

"Spehro Pefhany" "Phil Allison"

... Phil

HORSESHIT!

Such materials have those characteristics, but nobody uses such materials these days, and therefore sees no such resistive media build-ups.

Common MODERN contact media is typically Platinum. You probably read your spec sheet 50 years ago. That was how long ago it applied. Hell, the PINBALL industry cleared all that hash up. Where the f*ck were you? Contacts on reed type switching assemblies, which nearly all are some form of, have been low or NO oxide materials for decades. Even an enclosed switch has little short 'reeds' with contact heads on the ends.

Platinum exhibits exactly ZERO oxidation, even after 100 YEARS of exposure. The only way to coat it with anything is to have super moist, particle laden air.

Both it AND Gold are the best metals at NOT EVER getting ANY 'tarnish' on them. Especially Platinum. Look at the valence shell!

Imbalances can cause contacts with momentary HV pulses involved to migrate surface molecules from one contact and meld them onto the other, thereby causing degradation.

It's also sometimes called thermal contact rating, which may also be expressed as a duty cycle. There is also the I^2t rating which is used for fuse selection.

Ratings such as this are usually shown for power contactors and motor starter relays. They are rated for a certain HP and locked rotor current. We use contactors for switching transformer taps and setting series and parallel connection, under "dry" conditions with essentially zero current and voltage (other than leakage through an SCR snubber).

Here is a rather extensive glossary and explanation of relay terms:

Don't see platinum in any of the contact materials. Gold (mostly flashed and plated for low level signals), of course, and silver alloys with palladium and ruthenium.

Here is an extensive study of relay contacts, and platinum is only mentioned once regarding plating them with gold.

More information:

Paul

ends.

moist,

'tarnish'

other,

Platinum contacts were used some 90 years ago and some problems were found:

Paul

required to switch 16V AC max with 5A max current (i.e 80VA), Can I use this relay? or max current is 2A only irrespective of voltage and AC or DC.

Hello, the current rating is 2 A. Use at 5A is beyond ratings, very poor life at best.

X-((