My folks live in a gated community in Tucson. My sister is minding the house, which is about 30 years old, and had a strange story to tell.
"Microwave was running. Electricity went off in living room (lights and TV), dining room and hall lights. Kitchen lights still on, fridge on, d/w on, but microwave display was black and no light inside when opened. Microwave seems to be wired into lighting circuits. So when microwave tripped, all others on that circuit, 3 rooms of lights, went with it. Stove display on (not connected to microwave). Breaker box on front of house next to meter. The light blue breaker was tripped, mushy, would not move back with a snap, kinda mushed back to center."
"This morning went out and turned off/on the black Service Main breaker. Then turned off/on the red Kitchen breaker, then reset light blue Microwave breaker. Actually, all the light blue ones are were affected (3 rooms of lights) but the microwave was the only one in off position. The 4 light blue ones are collectively labeled Lighting, but one of them is also labeled Microwave. So it was two of the light blue ones that were affected, one controlling Microwave and the other controlling living room, dining room and hall lights. I think once I reset Main, all was reset."
I don't understand how resetting the main breaker could improve the situation of any other breaker downstream. Or how the Microwave breaker, when off, could affect the 3 other Lighting breakers (since those lights were also off). And what about the inability of the Microwave breaker to be reset? Mushy one day and resettable the next?