[quote"Ironranger"]I changed an old water service gate valve this morning in a basement. Came up copper, then brass fittings, then gate valve, then union and then galvy the rest of the way. I noticed there was a jumper ground type wire from the copper to the galvy going around the gate valve. I thought hmm, what's going to happen when I break this glavy union?[/quote]
I've had plenty of experiences with those. I usually carry electrical clamps and heavy wire to extend the ground before I break the union. I was changing one in a crawler under an ancient house and it zapped me pretty good. I was lying on the ground because that's all the room there was.
Many electrical codes required both a ground rod outside and a ground to the plumbing. We were required to run at least 5' of metal pipe outside the house for the ground.
These days, with plastic taking over, I'm sure the grounding practices are changing.
It can be any old device leaking juice to the ground.
I was doing something around a gas furnace once and realized something wasn't right. I checked outside and there was 120 volts on the gas main. The furnace had just been installed and the fool wired the power to the ground.
On a lighter note: my ex once called me to her new house because every time her boyfriend's daughter ran water in the sink she got shocked. I got there and got out my tester and picked up about 30 volts in the water flow.
Looking around, I saw an old electric frypan and a lid that touched both the frypan and the sink. I lifted the lid off the counter and the electricity in the water went away. :laughing: