If I string ten (or more) outdoor spot lights together, and run them from a relay that is triggered by a light sensor and turns on the 12 volt spotlights, then I figure that that will do it. My question is, if I’m switching that much current, will I be able to use a regular relay to do that? 400 Watts seems to be an incredible amount of power to switch. I’ve been looking into using a solid-state relay instead of a regular relay as I’m afraid that the power when the lights are turned on and off will arc if I use a regular relay. The arcing not only could be dangerous, but it would probably stop the relay from working.