On Sun, 22 Nov 2009 10:55:37 +0000, Andy Burns wrote:

My supply voltage tends to be at the high end, my UPSs spend about 8
hours a day here in "trim" mode

When I first got my UPS it instantly went into trim mode I thought it
was fault until I measured the supply voltage. I then logged the
voltage for a while then rang the REC, they came round agreed the
high voltage and adjusted the taping on our transformer. The
frequency of incandescent light bulbs going pop dropped from one a
month to one a year or longer.

From your plot 254v is above the upper tolerance of 230v +10% or
253v. Complain and get that average down to at least 240v, you
actuall have a pretty stable suppy at +/- 4v, ours is nearer +/- 10v.

--
Cheers
Dave.