Originally Posted by
Dennis McDonaugh
Looking at the link Pat provided, I see my symptom is listed in category C, AFCI trips between 1 minute and 1 month. There are 3 causes given, overload, bad breaker and arc fault. Obviously the circuit is not overloaded, it trips with nothing connected to it. I don't think the breaker is bad since I replaced it and got the same symptom with the second one. That leaves an arc fault which is hard to find. I can make sure all the outlets, lights and switches have good connections, but can't access anything in the walls.
I maybe wrong BUT (that never stopped me) I am thinking arc fault too. I don't see how you could have a arc within a circuit if nothing is drawing current of some degree. Just having a loose connection in the circuit shouldn't arc with no load as there isn't a complete circuit to anything. I suggest you have something else in this circuit still that you haven't identified yet being apart of it. The only other thing comes to mind would be perhaps water has gotten into something, but not sure how or if that could do it.
You mentioned about disconnecting a light switch to kill power to a light. This brings a question to mind. Is the power for the light from the box the light switch is located in, and the wire from the switch is sending power to the light, or is it a "switch leg" that is getting power in the box the light itself is in, and being feed power from the light to the switch and back to the light to complete the circuit? Assuming you are turning off breaker to disconnect wires on the switch, then turning breaker back on - if power is coming from the light to the switch you have one of the two wires between the light and switch hot regardless of the switch being on or off that could be the problem area.
Universal Laser ILS 12.150D (48"x24") 135 watts total, with 60 watt and 75 watt laser cartridges. Class 4 Module (pass thru ability). Photograv 3.0, Corel X6, Adobe Design Standard CS4 Suite, Engrave Lab laser Version 8, Melco Single Head Comercial Embroidery Machine, The Magic Touch System with Oki C711WT printer, and Graphtec CE6000-60 plotter.