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Mains voltage glitches in the NW UK today (25/10/2009)

J

Johnny B Good

Jan 1, 1970
0
Has anyone else been experiencing mains dropouts today? Not just this
afternoon and limited to the NW, but elsewhwere and right now (now being
17:47 GMT)?

I came home about 4pm GMT today after a visit to my brother and noticed
brief dropouts courtesy of the lighting. My wife asked me what the
beeping noise from the basement was which I hadn't noticed until she'd
mentioned it.

The beeping, of course, was from the 2KVA UPS in the basement (as well
as from the smaller 500VA unit in the office upstairs). I'd initially
assumed it was just a bad contact in the lighting circuit in the
downstairs shower room which is currently being refurbished but it
seems, according to my wife, a more general problem that has been
afflicting properties further along our road to the extent of being the
probable cause of house alarms being set off this morning.

I'm currently monitoring the mains using a laptop to record the mains
via a modified ac output wallwart transformer and CoolEdit Pro. The
fluorescent fitting in the office is particularly good at registering
(latching) these brief dropouts of half to one cycle (the longest
observed has been about 3 or 4 full cycles) by completely extinguishing
and requiring the use of its starter switch to restart it which gives
anywhere from a half to a couple of seconds blackout.

I'd guess we're seeing an average of 2 to 5 dropouts per minute but it
seems more like about 1 every 5 to 10 seconds as I type this. As I've
mentioned, these are just the briefest of dropouts anywhere from about a
quarter cycle to a full cycle. There was a real doozy of an extended
dropout just now of around half a dozen cycles or more. The dropouts
aren't producing a "flatline". I'm seeing what looks like a very noisy
half or one third peak voltage during these events (when I manage to
catch a glimpse of CoolEdit's rolling display).

The dropouts seem very suggestive of those experienced during extreme
galeforce weather conditions when the overhead lines suffer extreme
galloping to the point of transiently shorting out. The strange thing
is, we're not experiencing any such weather locally (Wirral peninsular)
hence my question.

I'm currently observing via my office window the local streetlighting
and some house lighting responding to these droputs so, at the moment,
am only certain that it's not a wiring problem on our consumer unit.

If all three phases from the substation are being equally effected, it
seems unlikely to be a substation fault and more likely to be a more
widespread one. I have yet to step out into our road to make more
detailed observations (ie answer the question "Is it one in every three,
or all properties suffering this mains disturbence? ;-).
 
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