There were but they didn't seem to help. There was even a supergrid pylon much taller and less than 100m away but it still hit our roof.
But the building to building potential difference also did a lot of damage as only one was struck. You can't really do much about that since all the current has to go somewhere when it reaches the ground.
AIUI a lightning conductor's primary purpose is not to conduct the lightning strike to earth, but to discharge the cloud above it in an attempt to stop the lightning in the first place. I believe there's a significant current flowing in a lightning conductor some time before a strike happens. If there is a lightning flash, it means the conductor has failed in its primary purpose.
But I can't believe that's why lightning conductors were used in the beginning; they must have been actually intended to conduct the lightning and prevent damage to the church tower or whatever, even if in those days no-one realised the true action.
One cause can be a disconnected neutral, which causes the voltage on the least loaded phase to rise (and the most loaded phase to drop). Worse case, that gets you ~400V. That could destroy the input stage of a switched mode PSU designed for 240VAC.
About 17 years ago, there was a power surge at home, which did for the ethernet port on an Sun Ultra 5 workstation. I don't know the nature of it, but it was due to a high voltage fault and the electricity company instantly offered to get the computer repaired. In the event, my employer just gave me another one and I don't think they bothered claiming back from Southern Electric.
My thoughts too
Two good points.
computers
I've had that, more of "melt-down" though. Tower case mother board on edge, for some unknown reason CPU power regulators got so hot they slid down the board...
I'm reasonably sure that will an "off-line" UPS. ie the mains is normally fed straight through or via a simple 1:1 transformer with a bit of filtering. Not sure if the Back-UPS models can also boost/buck the mains via altering transformer taps, might be a Smart-UPS feature. The invertor side only fires up to provide power when the mains fails.
An "on-line" UPS powers the kit via the batteries and invertor secion all the time. The incoming mains just feeds a hefty charger with enough umph to charge the batteries whilst they are being drained by the invertor.
Only an on-line UPS truely separates the suported kit from the mains.
It's donr once a month at UK hospitals.
I read somewhere that bamboo makes first class scaffolding. In Hong Kong they build skyscrapers with it.
Agree with the rest of what you say though.
Another Dave
Plus:
Strong, light, tough, flexible (so it shares load well), remains elastic at high bending strains.
Minus:
More difficult to join (I believe it is normally tied rather than clamped)
I was using a UPS - its output "surged".
20 years ago, in Lithuania, they were using larch poles. Any metal scaff tended to "walk" overnight. >
In article , Terry Casey scribeth thus
LOL!....
I Often wonder about this dual mains feed in a data centre after all where do they manage to get two separate off differing transformers from and differing HV feeds?.
Unless someone has the idea that different phases are different feeds?..
Mind you some SMPS's do cope with a very wide mains input variation these days..
Standard practice there..
Well broadcast site's do cope very well but they are well protected agin Jove's bolts.
Wasn't there a lot of lighting around the channel area on Friday night?..
In article , Chris Hogg scribeth thus
The idea is to "shunt" the discharge around whatever it is your trying to protect.
Messers Furse & Co did a very good online book on the subject once..
En el artículo , Martin Brown escribió:
Report on the so-called "power surge" in the Grauniad:
"Experts have questioned British Airways? claim that this weekend's catastrophic IT failure was down to a 'power surge', as the company's chief executive has claimed"
I was sceptical from the word go. Cruz is probably more familiar with cashing in his stock options and awarding himself fat bonuses than the subtleties of running a data centre.
Give enough money to your local DNO and they will provide diversity power.
Something like BA's data centre I'd expect to have at least two diversly routed 11 kV feeds from different Primary subsations (33 kV
There are documents on the web that decribe the power arrangements for football stadiums, that may host the larger competitions. Search for "fifa lighting power supply"
Maybe a toe-rag stealing the surge protection gear from the substation.
From the replies, it seems that a power surge is a nothing more than very short duration voltage spike caused by a lightning strike. I had wondered if that was all it was, or whether some massive bit of electrical gear like a carbon-arc furnace in a steel works suddenly shutting down might cause it, but as no-one mentioned anything like that, I guess I'm wrong.
Steel works! We are talking about the home counties :-)
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