can this Relay handle this?

Projects General Guidance
1

I have a 10A rated Arduino Relay shield. I have a 3A 12V device I want to power with it (turn on only after Arduino does some startup stuff). Will the 10A relay handle the 3A passing through it continuously? I know non SSD relays can get rather hot when turning on/off rapidly, but dont know what the case is with continuous On.

If it turns out to be risky, maybe I could have it the opposite way: power when SSD is in "off" state. This does mean the device will be powered for a split second before Arduino starts.

2

It should be no problem at all.

The rating is for peak current and you are well below that. Continuous will be no problem.

Weedpharma

3

Forgive my inexperience, so peek is usually higher than the continuous limit, right?
Thanks.

4

The peak is the maximum the contacts are rated at. It will carry that current but as the contacts arc when making and breaking, the higher the current, the more arcing and less life for the contacts.

The lower the current switched, the longer the life of the contacts.

Weedpharma

5

stuka:
Forgive my inexperience, so peek is usually higher than the continuous limit, right?
Thanks.

Yes, otherwise it would not be the peak.

6

Thanks, I understand now.

7

Or just get rid of the relay and use this SparkFun MOSFET Power Control Kit - COM-12959 - SparkFun Electronics but all you relay need is the restor and the mosfet and sparkfun sell the mosfet at less than a buck.

Mark

8

relays have multiple ratings.
motors have a rating because of the in-rush current on the motor coil.
incandescent lights are resitive heaters and resitive loads act differently.
DC loads are different still.

your relay should have these printed on the housing.
as long as your load is less that the rating you should be fine.