Hi Guys, Sorry if this post seems long but I want to include all of the relevant information. I have a new 27-inch Kitchenaid Microwave/Oven combo unit that I'd like to put in. Here are the specs: Kitchenaid KEMS378SSS05 The sticker on the unit inside the oven door says: 120/240V 120/208V 8.6 KW 7.2 KW The instructions say: "Models rated from 7.3 to 9.6 kW at 240 volts (5.5 to 7.2 kW at 208 volts) require a separate 40-amp circuit". They also say that I should use #8 copper wire. I just removed the old oven, which was gas. However, when the house was built in 1978 it was also wired for an electric oven at the same time -- there are unused #10 stranded wires ("10 AWG CU 600V UL OIL RESISTANT I E-13662") leading from under the old oven back to the breaker box (there is no sub-panel anywhere). There are 4 wires -- 2 blue, 1 white, and 1 green, all coated. The green and white wires are connected to the bus in the breaker box. The blue ones are completely disconnected, but through simple testing I've determined that the disconnected wires I'm seeing in the breaker panel are the same ones I'm seeing at the oven junction box. The wires are in flexible metal conduit. The breaker panel also has two completely unused breakers: one is 30 amp, one is 40 amp. The oven comes with 4 wires in a pigtail: black, red, white, and bare copper. Red and black are #8, white is #10. My question is this: Can I get by using these already-installed #10 wires, or do I have to use #8? I know that, typically, 40-amp circuits require #8 wire, and that is why Kitchenaid is telling me to use it. However, I also know that the distance the current has to travel makes a difference as well. The distance the current will have to travel from the breaker box to the oven is a maximum of 35 feet. My calculations indicate that the voltage drop in these #10 wires will not be a problem over 35 feet for a 40-amp circuit. To me, this result is supported by the fact that there is a 40-amp circuit breaker in the box. There are no wires larger than #10 coming into the box, so the original electrician must have thought that the #10 wires were good to go with the 40-amp breaker over the relatively short distance to the oven. If I were building the house now, I would use #8. But since the #10 wires are already there, I'd like to avoid the hassle and expense of putting in #8. Any thoughts? Thanks in advance!!

I have a problem with a GFCI circuit in my garage (lights, outlets, garage door openers). There is a light switch by the door used to enter the house from the garage. Sometimes, turning this light switch on causes the breaker to trip. It seems that using the garage door openers do not trip it, just the switch. The house was built in 1983. We bought the house two years ago and had some electrical work done - including adding the GFCI circuit form the garage. Prior to adding the GFCI circuit, we had no problem in using the light switch. I had an electrician from the company that installed the GFCI to look at the problem. He thought it was the lights, so he tested by bypassing each of the four lights. Eventually he gave up and indicated he could not determine what the problem was. This problem is not weather dependent. I can start flipping the switch up and down at any time, and eventually the breaker will trip. For the past year, we have been using the garage door opener light (this does not seem to trip the circuit) instead of using the main lights. Does anyone have any ideas or tests to run to determine where the problem lies? Or do I need a major rewiring of the garage. Thanks, Ken