Some interesting comments there about instrument accuracy.
On the service where I couldn't obtain a meaningful Ze reading, I'm not quite sure where the transformer is located. There's the usual "middle of town" xfmr feeding the 3-ph network along the High Street, but that's about 200 yards away. I would have expected a slightly higher Ze if it's coming from there.
However, there is a new xfmr located right across the street, put there when a new supermarket was built two or three years ago. The service entrance I was measuring from is right by the front of the shop, and the xfmr is literally about 20 ft. away across the road. I'd always assumed it was only feeding the supermarket, but perhaps the units in the shopping center were also transferred to it to ease the load on the High St. sub-station. There might even be another xfmr somewhere around the back of the complex that I haven't noticed. I'll have to take a closer look.
