Almot wrote:
When I replaced old 18W bulbs with LED of equivalent brightness, the current dropped to 0.4A per bulb. To turn 3 double domes like in RV will require 2.4A total. Residential switch is rated 15A. How bad can be in-rush current, to worry about this?
The inrush current, per se, is not the big problem really. It only flows after the switch closes, and is not much different for AC and DC. It's breaking the connection and interrupting the current that is hardest on a switch, and DC is inherently harder to interrupt than AC. It's not just the magnitude of the current (though that does play a significant role), it's how soon the arcing breaks down.
That is, of course, separate from the overall current ratings that may at least partly be driven by the size of the contacts in the switch. Exceeding the maximum, particularly for a relatively long span of time (more than a brief instant, say), could cause trouble due to heating and maybe be a fire hazard. That's a separate issue from the type of electric supply.
As a practical matter, switches rated for AC only will usually work pretty well for modest DC loads--maybe not to their full rated lifespan, but still acceptably well for many uses. When the worst case for a switch failure is that either you're left in the dark in the kitchen or else you can't get any dark in the kitchen, one needn't have any real scruples about using the wrong variety of switch. If it fails eventually, replace it again and carry on. If the switches keep on failing with any frequency, use a different sort of switch. There's no need to overthink things here.
