Question about voltage in U.S. house built in 1890

[amyk]

I suppose the ground rods at each of our homes as well as the connection to our city iron water pipes (how's the electrolysis on those pipes I wonder) is forming the return? Is this typical of the U.S. power grid?? Seems like a poor way to do a power return and I wonder if it also leads to an early demise of the city water pipes??

It's AC. If it was DC, even the ground rods would also corrode away rapidly.

https://en.wikipedia.org/wiki/Single-wire_earth_return

[chrisclarke]

My house in Cape Town, South Africa was built in 1900 and renovated in 1949

The gent who renovated was the City Electrical Engineer.  In 1949 they used ungalvanised steel pipes.  About 2/3 of them have gone rusty, some areas completely corroded away.

I bought the house as a deceased estate in 1984 and have been replacing the cloth and rubber cable with PVC and/or "Flat twin and earth" or "Surfix" which is also a 3-core cable but with an aluminium shield as well.  Its a 230VAC mains and the cable is 2.5mm diameter

In 2020 the electrician replaced the outside earth rod which is a 2 metre x 25mm copper rod, with 2 rods, each 15m apart

At the other end of the house, which is 35m away, I also fitted an "earth mat" to ensure a completely quiet and safe earth.

[themadhippy]

hope you bonded the rods and earth mat together

[CatalinaWOW]

Wiring and electrical codes were initially quite local, and thus based on local conditions.  An adequate earth return can be quite different. An area with sandy soil that is heavily contaminated by sea water and an area with almost solid granite and what little water there is is quite pure.  Also it has only been a little over a century since electrical distribution got started and many things about corrosion have been learned in the meantime.  So everyone should be cautious about applying their expectations in a new location.  What was done historically may be quite different than what you have found previously in a different location.  Even without throwing in the long history of DIY bodges.  I have done many things knowing that they will not last forever.  Sometimes I intended to do a better job later, sometimes I knew it would last as long as I would be using it.  When I remember I warn future users/owners of these temporary fixes, but my memory is no better than most so some escapes have occurred.