Don't know much about residential wiring, but learned three things while dealing with tripping gfi's. I had to replace the gfi outside TWICE due to ants building nests and frying themselves. Also, there are weather-resistant rated gfci's available which is what I now have outside. Lastly, it turns out that if you have a gfi in your main panel or in a circuit before the gfi causing problems, the two gfi's will not play nice together. Hope this helps.