BACKGROUND: Hi this is in Chicago so we use EMT Conduit as our grounding system and only use an EGC for stoves/dryers/sump pump/ etc... so I was working with my cousin to demo stuff in a basement in a residential Chicago home where only one 20 AMP CIRCUIT BREAKER with ONE circuit was provided by the "Electrician" which connected to 2 outlets in series 15 ft apart from each other. This circuit provided the service for tradesmen (i.e. charge power tools, use heavy duty masonry drills/ compressors/ microwaves/ heaters and Lights) to carry on their task. However, during the plumbing renovation one of the plumbers cut and removed the old plumbing copper pipes that were attached to the city's main water supply and left the remaining old copper pipes in the ceiling (idky they DID NOT remove the rest of the pipes. These copper pipes had a 12 gauge conductor attached to it to provide the "Grounding" factor. Now when the plumbers did this it led to voltage fluctuations to the point where i could NOT charge my cordless battery packs (18V ryobi and 18V bosch) and barely got any juice for my USB C phone charger. There was a pattern every second or half a second my equipment was able to get full charge but they would reset and i would hear a clicking sound, continuously.
PROBLEM: electrical service was fluctuating at an inoperable level.
-- We called "Electrician" and he took out his multi-meter and was getting different voltages from Neutral and Hot side about 120V HOT and 80-105V NEUTRAL or vice versa. He traced it back to the old plumbing where a white insulated cable was attached to the top/demo'ed part of the old copper plumbing system (which was still not removed at this point, which was a 2 day ordeal coordinating and communicating with "Electrician" and plumber. so he removed the white insulated wire from the old "Floating" plumbing system(which will eventually be removed) and connected it to the new copper plumbing system which went underground per-concrete poured.
SOLUTION: The "Electrician"said that he "Jerry-Rigged" a 12awg conductor from utility/gooseneck and connected it to the old plumbing system to use it as a grounding system. so when the old plumbing system was cut out from the earth, he simply attached the 12awg conductor to the new plumbing system in the earth and problem was fixed. Mind you the wire he "Jerry-rigged was connected to the NEUTRAL Conductor coming from the service lines outside above, bypassing the main panel, and being attached to the plumbing. The service panel's only circuit breaker had 2 conductors, 1 HOT and 1 NEUTRAL and the NEUTRAL Was grounded via the jerry-rigged conductor connected to the NEUTRAL Utility.
*Above was the scenario in chronological order of events.*
My question to you Guru's is, Why on earth was the voltage fluctuating when the ground system was physically removed i.e. plumbing?
I thought Electrical circuits were not influenced by a grounding system and that the grounding system on affected voltage spikes i.e. lightning etc...
the circuit was still closed as our equipment was still charging (barely but still charging with a 25volt potential difference on N and H ends).
I know it had to do with the plumbing but once it was cut and just floating in the houses frame it would just be that, no loads or anything for it to energize im assuming....
Can you please break down why on earth was voltage fluctuating ?