I'm just finishing up my house, getting ready for the final inspection. When I did the electrical I was required by code to install and arc fault breaker for the bedroom circuits. Newer houses are soon to require arc-fault circuits everywhere, at least in my county. Not a big deal other than a bit more expensive. So far universal motors haven't popped the breaker.
Then the other day I picked up some LED lights and was eager to make use of 1.3 watt luminescence. I put them in light sockets on the bedroom circuit. They work fine, although they aren't as bright as an equivalently rated (40 watt equivalent) CFL.
I discovered that I now have night lights. Even when turned off they glow softly. I'm not sure how exactly, since the circuit is not complete. If I pop the breaker, the light goes out completely. If I put the LED bulbs on a different, non arc-fault circuit, there is no light produced. As soon as I put them back on the arc-fault circuit, they glow. When turned on they put out the normal amount of light.
I'm going to assume this has something to do with how arc-fault breakers operate, but haven't found a good explanation anywhere. Does anyone know the details of how arc-fault breakers work ?