[BC] 110 V DC

[Jeffrey Kopp]

>>[Peter/Robert:] >My utility, one of the largest in the country, had an average
>>voltage of 127.5, this which was for a nominal 120 volt system.

>My UPS has a front-panel voltage meter, which varies between 117 and 120
>volts. I have never seen anything higher than 121 volts. I am on Pacific
>Gas & Electric in the Bay Area.

Seattle City Light used to (1980s, might still) run hot (low to mid 130s) in town, due to some arcane detail I am now fuzzy on (something like an early-design infrastructure with long distances between substations) to maintain acceptable voltage at the far ends. I remember being quite puzzled by this when I stuck a new VOM in a light socket. I doubted the meter, but later learned the reason when it was explained in the papers after people noticed their motors and light bulbs were not lasting as long as they were supposed to.

I remember reading in the late 70s about several thousand hapless New Yorkers who still had DC service because the buildings they lived in were never rewired for AC and Edison was obliged to continue providing DC to them. The tenants had to be creative, buying DC appliances like refrigerators from overseas. There was then but a sole model of TV set that would operate on 110V DC (an Emerson, I think), the inadvertent result of a design choice made in its power supply. I was surprised to read in this thread it wasn't until last year DC service could be discontinued in that city.

During a cold snap in 1977 clocks gained about 30 seconds over a week in New England; to maintain voltage they had to run the generators (and thereby the grid) overspeed for a long enough stretch that they were were unable to correct the error. Instead they just announced it in the press a couple weeks later. I was surprised by this as I'd grown up in BPA-land (the largest unit of synchronized power on the planet) where one thing we could always count on was 60 hz.