especially with 240 volt rated elements on a 208 system. If POCO regulation were stuck on highest tap this think would maybe see about 235 volts max instead of a normal around 212-216.
Megger and knowing how to use it will probably find OP's problem pretty quickly.
It’s an extremely dated network in this city’s downtown area most of the time we see service in this area struggle to even get 208 so it was out of the ordinary to have such high voltage per phase . It took utilities a few days to get it taken care of . I was more concerned about the 120 V single pole circuits throughout the building itself especially the freezers and coolers which have a lot of low-voltage components on them so fortunately we got there early enough in the morning a few months ago to catch the problem which was when we burned up one of our battery chargers just by plugging it in and immediately diagnosed the situation called utility unplugged everything fortunately the business was not open yet to the public. But we seem to be OK now we bounce between 208 and 215 V which is better than what it used to be, which was between 202 and 207 V . Ultimately, the problem was internal in the water heater itself. Apparently when we had our cold snap a while back one of the copper lines that went to the pecks was corrupted and water was running over the top of the water heater. We recommended that they relocate those water heaters sometime ago they are not in the best environment it’s a room that access is the pit of the alley where an old street elevator still remains but is inactive it dates back to the 1930s due to this there is an exceeded amount of moisture in wafting cold air that enters this area.
