Outcast_Searcher wrote:-snip-
So, I suspect that overall, the safety discussion above is valid, but the answer to a "reasonable" level of safety is probably somewhere in the middle. Knob and Tube wiring is obsolete (he had mentioned that at some point), but it's not like knob and tube houses were burning down left and right.
No they were not. When wiring went from Knob and Tube to cloth insulated, safety improved. When we went from cloth to vinyl insulation, safety improved. When we went from fuses to circuit breakers, safety improved. It's simply not visible to a single individual, unless that person is a statistician working for the UL compiling the results from tens of thousands of residences. Not to mention, this is the accumulation of knowledge from over a century of data collection.
You either believe in the numbers, or you trust your instincts based on your personal experience. The best practices in electrical, plumbing, the building of earthquake-resistent structures, weatherproofing, insulation, etc. are derived from the experiences of millions of people, just as are the best practices in medicine. You collect the data and analyze the results, and when you get a safer outcome, you change the NEC, the building code, etc.
Certainly, the world is replete with people who would disregard what the numbers say, and do their own thing. I'm not one of them. If I am in the market for a new home and I see obvious amatuer construction, or plumbing, or electrical work, I'm going to ask for an inspection. I will consider the cost of bringing the structure up to code in whatever bid I make. If I am building a new home and decide to exceed the minimum worksmanship and safety standards required, I'll do so. My money, my decision.
The matter of grounds and electrical systems are a whole topic in itself. In fact, most destructive currents enter a structure
through the ground conductors themselves. Amazing things happen with lightning.
I once specified the computer room power in a room approximately halfway up the tapered black Chicago skyscraper known as the "John Hancock Center":
This is a buiding constructed of massive steel structural beams and steel plate/poured concrete floors, then clad in glass. There are "equipment spaces" every 10 floors in the building, which means that when you cool a computer room, you will run copper plumbing as much as 5 floors up or down, to the nearest equipment space. The massive A/C compressors were connected to the evaporator units in the computer room, where they blew cold air under the raised "plenum" floor. You could alter the distribution of cold air by locating perforated floor tiles near your equipment, a typical sort of arrangement where equipment is reconfigured frequently.
You would not think that a computer that was located hundreds of feet from any building exterior, in the center of a steel structural skeleton of massive steel beams and girders, would ever experience lightning damage. But ours was gutted by lightning and I was sent by my irritated boss to do a post mortem. The lightning had struck the top of the tower and was conducting itself down towards the Earth, when it encountered those A/C compressors, which were interconnected to the computer room with 3" diameter copper pipes, brazed together in one continuous piece. Of course, copper has lower electrical resistence than steel, most of the current flowed down the piping and into the computer room, where it was bonded to my carefully specified 1" by 1/8" super-heavy duty copper straps that formed the equipment grounds. Crispy critter computers was the result, and the HVAC guys got the blame, for not installing "dielectric unions" in the cooling loops to break the circuit.
In residences as well, the path taken by destructive lightning currents is most often the grounding system itself. The two ground rods mentioned above is the former "best practice". The new "best practice" is to drive a ground rod every 6' around the building, and interconnect them with a copperweld cable loop buried about 6" below ground. The idea being, make a low resistence path for lightning striking the ground anywhere nearby, so that it flows AROUND the residence and NOT THROUGH IT. The single connection between the circuit breaker panel and the ground rod system remains at the main panel, and ALL other external connections, including water and communications, are nearby the electric service and connected at the same point to ground. If you have solar panels or antennas on the roof, you ground everything to the "main building ground" at that same point where your electric service enters.
As you may have guessed, I also have that EE degree, and had practiced EE for 36 years when I retired in 2015. But I am still an IEEE member and still bound by the code of ethics to give good advice. The other EE mentioned above by Outcast_Searcher seemingly has similar ethics.