DrWho? wrote:
Just an inquisitive question. My UPS seemed to go mental last night/this morning (around midnight Sat Oct 1st) flicking between battery and mains repeatedly for a few hours.. But no flickering lights or anything..
Im wondering if anyone else had something similar? Im assuming it may have been the power company doing something weird re: daylight savings?
Assuming the UPS or batteries are not at fault then a loose wire in the power network will do that, certainly if there is a breeze.
Had the same problem turned out the pole connection was loose. Took allot of convincing to get the fault fixed as well as it was not effecting the lights etc.
See if it does the same thing next time you have some wind.
After 20 years of being in the electrical industry myself, I would be more inclined to go with Gavin's and Chris's views, even though I mentioned the ripple control system. (I have heard UPSes react to the ripple control signal - but not for two hours). I have graphed a couple of UPSes around the University Campus and seen the mains frequency jump around between 49.5 and 50.5 Hz at this time of the night which is why I brought up frequency excursions, but this time of the day is a very popular time for WEL to do Network Maintainence on the 11/33KV lines. With the 230/400V incoming supply, typically it is noticable with lights dimming, etc, especially when you turn on large loads such as your oven. Loose neutral wire is a bit more of a gotcha, but with heavy loads, it's pretty obvious (that is why I mentioned the lights dimming when the oven is turned on). Also it wasn't windy on Saturday night, I just checked my weather station graphs. It sounds to me like it was a one off incident which went away after two hours, which is why I haven't considered the mains to the house or the UPS itself. Kyle, if it happens again, then let us know.