I'm having my AC system replaced and checked out the wiring of my existing dedicated 30amp 220v circuit used for the old AC. When I took off the service panel cover, I was surprised to see that the NM cable for this circuit connected to the 2-pole breaker breaker only appears to have 2 conductors. I understand that it doesn't need a neutral because this is a dedicated 220v with no requirement for 110v, but why isn't there also a ground in order to connect the AC chassis to the service panel ground? Even weirder (to me) is the fact that even though this circuit doesn't appear to have a ground wire (I didn't even know there were NM cables without a bare ground), there IS an outdoor shutoff breaker next to the AC, and the wire from that to the AC DOES have 3 conductors (i.e. black and red hots, and a green which I assume must be ground). Is it possible the outdoor shutoff has a separate ground connected directly to earth? If so, that doesn't seem right because 2 different points connected to the earth can have a small voltage difference? Also, while I had the cover off, I looked at all of my other 220v circuits (i.e. dryer, stove, well pump), and I don't see a bare ground wire on ANY of them at the service panel. The house was built in 1979, but I had the electrical service upgraded from 60amp to 200amp when I bought the house is 2009. I did this because the home inspector recommended it (e.g. there were double-tapped breakers and other issues). I didn't ask a lot (or really any) questions at the time when this upgrade was done, but I've been learning since then over the years. For example, I didn't know about backup generators at the time I bought the house, and would have asked the electrician to at least add a transfer switch when he was replacing the entire panel. When I think about this, it bothers me that he didn't even suggest this...

I own a 110 volt 20 amp Hot Tub it has a 15 amp GFCI plug I also have dedicated one circuit one outlet for just hot tub. first three months no problem then one day no power to the hot tub the GFCI plug tripped so I reset plug turned on hot tub and pop it tripped again. I call hot tub service line they said it was the pump motor so they sent me new pump . The pump install easy the electrical was one plug into the control board color coded. Filled tub plugged it in tried to turn tub on and pop I am like what the hell so for giggles I wired direct plug no GFCI into hot tub plugged it in and pumped started rite up. So I get a new GFCI plug they have same one at Home depot go figure anyways wire it up plug it in and POP . So I call service center they are sending me new GFCI apparently a 20 amp GFCI . I am thinking this is not the problem since it ran for two months with out issue. Some one suggested I have a double ground I have no idea what that is or how to troubleshoot that any head would be great to have thanks. Jim