Another classic example of what could be considered non objectionable, is dryers and ranges connected to 3 wire setups in pre-1996 homes and in some jurisdictions the rule for 4 wire setups wasn't universally enforced until the early 2000s or so.
They those have a neutral or a ground wire? If a neutral wire: How would that produce objectionable current? Sure, it's unsafe if the neutral wire breaks. But precisely because the 120/240-V dryer/range has three 3 wires (two hots and neutral), no current flows through any ground wire or metallic object under normal conditions.
Did a service upgrade about 12 years ago. I was called back for something else and saw that the system grounded neutral came undone. Out of curiosity I out an improve around the GEC and found 13 amps flowing though it. Another time I had potential of 110 volts between two 4" square boxes up in an attic. Objectionable current flow is fascinating and once you understand it you are definitely an electrician. Great video Ryan!
Have two cases of objectionable current.First one was when somebody used 14/4 AC cable to supply 4 branch circuits while using the steel jacket for the grounded conductor. Over time somebody replaced the 15 amp fuses to 20 & one 30 amp fuse. Steel jacket was very hot. Second case in my large city every large street has 3 phase 13.2KV lines but they always only run one high voltage line to primary of it appears to me to be auto transformer connection . Every copper water service & steel gas service that I used an Amprobe on had 1/4 to 3/4 amps on them even if main breaker was off. If cheap utility company would just run two wires to the primary you would not have any current flow. Over halve of the houses on my street had leaking gas service pile leaking. The gas company comes out and digs up the sidewalk where the 6" main is and pulls a plastic tube thru leaking pipe and glues it at both ends. Often wonder if the steel underground pipes would have lasted longer if they had no objectionable current on them. Can Remember being told that is dangerous for any underground pipe to carry current because this could cause arcing to a nearby better conductor and eventually this arcing will eat away the pipe causing a leak.
Adding another wire wouldn't solve anything. Current takes every possible (completed) path, so if there is current on the pipe now there still would be then. This is simply a biproduct of using a solidly-grounded system.
I've got galvanized steel water pipe and two grounding electrodes at my house. I read about half an Amp on one grounding electrode conductor, but none on the other, or the water pipe. They're all wired up properly as far as I can tell. I've also been hearing that while not an electrical safety issue, current on a water pipe may be leaching chemicals out of the pipe and joints, causing a potential water quality issue.
Thanks for taking the time to make these videos. I was wondering about the waterpipe issue. I saw a video from the EMF explorer channel and he states that the current flow on the water pipe causes high emf which can lead to health issues overtime. I have seen other videos stating similar issues and levels of emf when neutrals from two different branch circuits are tied together in a box. One of the fixes that was shown was to remove the jumper that bonded the pipe on either side of the meter. The rest of the house was still bonded but after disconecting the jumper there was no more current flow or emf present. Seems like if emf is as bad as they say it is, why not break that connection and just cover up the portion that isnt bonded to the rest of the house. If the panel has a ground rod already and all the pipes are bonded that could contact wiring and become energized then it seems like it would be better to not have the extra emf present in the house/building by breaking the connection to the street. Curious on your thoughts about this. I could send a like to the videos I'm referring to if you'd like.
The big question to me is how much current on the GEC is acceptable? How much voltage on the GEC is acceptable? I've put my Fluke around some of them and occasionally see 60v+ and 100a+. On others I see nothing. No current, no voltage. Never have I seen a clear definition of what is acceptable and what isn't. I've seen some of these that were enough to shock you touching them with the main breaker off. And the copper pipes are not that common here, they're all iron and really rusty. Maybe that's the cause of the higher voltage.
It is often unavoidable. We use a multi-grounded neutral conductor for utility distribution. We have to connect to the water pipe to keep it from becoming energized, and the second we do that it is in parallel with the utility neutral.
