Blackouts

[dj-gabriele]

Hello everybody!
I was wondering how often blackouts happen in your area, be them the 5 minutes long interruptions or those large scale disruption that leave you in the dark for half a day.
Last time I experienced one was in 2003 when the Italian nationwide black-out happened because of a fallen powerline from Switzerland that cut off most of the power transmitted at that time. I remember the inconvenience as we couldn't even flush the toilet nor use A/C in the summer heat! Land line telephones on the other hand hopefully never stopped working!
Luckily since then not a single one ever happened.
I had blackouts only when our meter became overloaded and the breaker tripped because we had too many appliances connected, problem solved when we upgraded our service (but still limited to 6kW)

 

[cfz2882]

i had a 1 1/2 day blackout about 7yrs ago-snow +ice storm brought down power lines
one gas wall heater was not dependent on electricity so kept working.had a couple
car batteries charged so used those to power 12v lights and TV.Was worried about
my aquarium fish getting too cold but they survived.

 

[whirlcool]

We live in a semi-rural area so the power here is somewhat unreliable. We can expect at least 10 on and off flickers per week with a power outage of at least 1 hour once per month. Last time it was 6.5 hours. I called the power company to ask why and she said a farmer hit a power pole with his tractor taking it down.

We also get lots of power surges. Enough so the television will go full brightness for about 15 seconds or so. We had one so bad the microwave turned on for about 10 seconds one time. So everything we have is on a surge protector or UPS unit. The power company only gives you the excuse that our power system is old (1920's old) and that we are due for an upgrade in 2014. In the meantime this area is quickly developing from what it was when we first moved here about 6 years ago. Fix or six new subdivisions have opened with another 4 or 5 breaking ground.
Personally, I think the system we have is old AND wasn't designed to handle the power they are pulling from it with all the new development.

 

[DADoES]

 
Blackouts of noticeable/affecting duration, rarely as a matter of normal course.  I'm on the same supply circuit as one of the schools so the local power company makes an effort to maintain stability.  There were a couple incidents of late-afternoon rolling blackouts during the summer due to power shortages on the state grid.  I didn't notice any but other areas of town, and other cities across the state, did.

Per my computer backup battery logs there was a "blackout" on 11/21 of enough duration to trigger the battery for a couple seconds.  A couple line noise incidents last night.

 

[petek]

Not very often here in town, a couple of storm related ones this past summer in our neighborhood when a branch somewhere must have knocked down a line. The power co. is very quick in getting things back. However my niece 35 miles out lost theirs for a few days when a tornado brought down a few of the big big transmission lines.

 

[ronhic]

Blackouts are rare here in Canberra. Lights may flick once or twice a year, but the power rarely goes out. If I had to put a number on it, maybe once every 10 years or so for a few hours.

 

[cornutt]

Power at my house was out for about 4-1/2 days after the April 27 tornado outbreak.

 

[arbilab]

In Austin TX over 18 years my power was out probably a total of one hour. Including when the substation transformer exploded in the middle of the night but that was still only 30min.

In midcities DFW, my power was out 6 hours (3 x 2hr) the first two months I was here. In perfectly clear calm weather. I chased it to low-management level at the utility and never did get an answer why.

Though it didn't go out last winter when several generating stations froze and some areas had rolling blackouts, it's continued the 2-hr outage thing for no apparent reason the whole time I've been here. Sometimes as often as 3 times in one week and again this is when weather is clear, calm, mild. Pretty sorry performance and no explanation available or apparent.

 

[iheartmaytag]

Picture this. . .Wichita. . . 2005

We had the perfect storm of freezing rain for about two days.  The temps stayed just right where the rain was liquid as it fell but froze instantly when it touched the surface.  This ice began coating everything including trees and power lines.  The result was wide spread power outages.  Trees were falling, power lines were sagging.  We were lucky, blessed as some call it.  We lived in a mobile home court and were in the newer portion where the power lines were under ground.  The neighbors just across the street were not as fortunate and when a tree gave the entire park, save those of us in the back which had a different feed, were out of power.  The temps remained low for a week, but the power took up to two weeks to return in some parts of the city.  The next day only two of the forty employees where I work were able to make it in.  I wasn't one of them, didn't even try.

 

We had several neighbors that just walked away from their homes and left them as water pipes started to burst.  My boss lives out in the rural area had a generator, because he was used to unreliable power.  There were several people that tried to stay warm using charcoal or other unsafe means and paid the price. 

 

Since moving to our house four years ago we have had some power interruptions, none lasting more than a few hours.  Not to say that there haven't been storms that have knocked out parts of the county, but we have been lucky.  When we were looking for our house I wanted a fireplace for emergency heat if needed.  We ended up with a gas insert instead, but it's still there if we should ever have another winter of '05. 

Wichita Ice Storm, 2005

 

[countryguy]

I live in the country and power outages are quite frequent. I just had one on Sat. afternoon for about 1/2 hour. Fortunately I have a whole house stand by generator installed so I just wait the 30 seconds until it kicks in and then I have full power to the house again. Very handy, especially on Sat. when I had nuts & bolts baking in the oven when the power went out.

Gary

 

[whirlykenmore78]

Power going out.

Here in Prior Lake (suburban Minneapolis) the power don't go out enough to be any great problem. Maybe for a couple hours here and there. Usually a transformer blows up or someone tries teaching the car how to fly and hits a pole. Longest I can remeber was 11 hours. I do know people from elsewhere in the Twin Cities that have more and longer power outages.

 

[daveamkrayoguy]

POWER OUTAGES! DaveAMKrayoGuy writes:

I have to be glad my 'tricity never went out when my records were playing except once when it interrupted my Ad Ames WHO WILL ANSWER? album... Instead of waiting hours (luckily not days) for it to start again, I just removed the needle & put it away promising to hear it when the power went back on...

I have been lucky only recently to only have had the electricity go out for only a few seconds (although when it interrupted my Bobby Goldsboro HONEY: 23 GREATEST HITS w/ an additional 4 more songs burned on, I could at least start the CD over again, as I had just started it playing right where it left off)...

There was one power shortage where my block had electricity, while the next one was w/o it for days--almost A WEEK!

Imagine the irony, though: one time THAT block had electricity & my block went out while one house had all these flood lights, lamp posts on the lawn TWO freezers & a big power consuming side X side fridge, electric range, etc. ALL ON!

Lastly, in 2003 there was a power outage that I believe covered at least 5 or 6 states, including Michigan! Luckily I was in Florida & watched it on the news & called my mom to see how she was doing...

-- Dave

 

[tolivac]

Power in my area is pretty good-even during hurricanes.At the transmitter site years ago-had a scheduled "blackout" from CPL-they had to repress the oil in the 115Kv-4160V transformers in our substation.Was interesting to watch-the filter"press" was in one semi trailer-other semis hauling in transformer oil-took several trucks-this went on during the mid shift-at daybreak-the power was back on,CPL's crew left.

 

[arbilab]

Toli, our station (NBC TV OKC) had dual 7kV feeders and we had auto-transfer gear onsite. One studio feeder exploded underground and of course before they could fix that the other one failed. We were halfway through wiring the remote truck generator to essential systems when it came back on. Would have been futile but the transmitter feeder did NOT fail.

I loved the broadcast business, never knew what was going to happen. Eventually after I was gone a tornado took down the aux transmitter tower.

 

[cornutt]

"One studio feeder exploded underground and of course before they could fix that the other one failed. "

Amazing, isn't it? Get this: Some years ago I worked in a NASA facility that had the following:

* Two redundant 4160V feeds, coming from different directions and different parts of the TVA grid.
* A UPS system, capable of powering all of the computers and a few of the lights.
* A generator, capable of powering the entire building except for the A/C chillers (which had their own generator).

One day I'm in the main computer room and everything goes out. I happened to be near where the power transfer remote panel was, and when I looked at it, it was totally dark. WTF? I wait a minute to see if the generator kicks in, but nothing. I managed to find my way to the dock door, where I could hear the generator running, but obviously not under load judging by the sound.

Here's what had happened:
1. The UPS was offline that day for scheduled battery maintenance.
2. It was very windy that day, and in the morning the wind had managed to short out part of the on-base grid that fed our secondary feed.
3. At lunchtime, the wind blew down a line feeding our primary feed.
4. The generator started up, but the transfer switch jammed.

We wound up using a recently-installed emergency bus, which was connected directly to the generator, to get power restored to the fire protection and the computers, and get a few lights on. This involved walking all around the building and pulling a bunch of manual transfer switches.

 

[arbilab]

Amazing. And that's NASA, not local NBC. If we look at most air transport disasters we find the same cascade type failure of systems thought redundant.

What amazed me was when Austin Electric got the entire system working again within a half hour after a 138kV transformer literally exploded. Manual transfer switches, can see them up the poles, borrowing from adjacent substations. But coordinating that through dispatch in 30 minutes, they had to have a plan before it happened. Hats off.

 

[tolivac]

At the transmitter site where I work-it has a 1.8Mw 4160V Cat generator as a backup-and for load mangement.During the summer-CPL has us run the generator for the day.If it fails--we have to shut down transmirtters as fast as possible.the load management penalty charge is VERY high.Then we have to call the Company that services our generator.And our generator has had problems-tripping when under heavy load-so we have to be careful in adding or shutting off transmitters.Run the transmitters at lower power.And a mystery-the utility breaker at our substation tripped-unknown why.We still want to know.And it could do it again.An the breaker has to be manually reset-linemans pole and FULL arc protection gear.The BANG of a stored energy medium voltage breaker can be scary-the spring mechanism is stronger than a bear trap!This was shown during the Powell electric breaker training- a video was shown-the mechansm breaking a 2x4!HANDS AWAY until the trip-close springs are decocked.

 

[cornutt]

Arbilab, we were lucky in that there was no mission in progress that day. (If there had been, they would not have scheduled the UPS maintenance.) We were puzzled about the transfer switch failure since the generator and switch were tested, under load, every week. When we looked into the procedure, we found out that when they did the generator test, they operated the transfer switch by hand; the motor drive was never testing. After that, we changed the procedure to have them do the transfer by pressing the button on the remote panel.

I can tell you an even better one. Circa 1995, the Mission Control Center at JSC -- the one you see on TV -- still had its original backup power installation from the 1960s. Since there no practical UPS systems back in the '60s, the way the did uninterrupted transfers was to have a gen set capable of being synchronized with the utility. The idea was that they never waited until a utility interruption actually occurred; whenever weather or some other condition posed the possibility of a utility outage, they went ahead and started the generators. Before transferring, the generators would sync to the utility feed. Then they'd close the generator switches and the generators would be in parallel with the utility feed, and then disconnect the utility. That way, they got uninterrupted transfer. When the period of threat ended, they'd do the process in reverse: bring the utility feed back on line, and then take the generators offline.

Well, one day during a Shuttle mission, weather came up. They started the generators, and... didn't notice that one of them had failed to sync. So when the generators were put on line, Bad Things Happened. Breakers tripped, stuff smoked, and all of the generators shut down, leaving the MCC blacked out. They were close to having to activate the emergency control center at Goddard (which, per the flight rules, would have meant immediate end of mission), when someone managed to get something rigged up and got the building back on the utility feed.

 

[arbilab]

I love the phrase "bad things happened". Just the phrase, not when they really happen. Geez, you'd think the switchgear would be smart enough to detect nonsync, but that's what you'd get for thinking. Or at least line/load isolation so one fault didn't crash the whole sumbish. It would have if *I'D* designed it. But then some budgethead would come along and say "Back off brain boy".