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Bad "Buss Duct" Closes Federal Complex for a Week

posted by azrael on Monday July 28 2014, @08:50PM   
from the impromptu-vacation dept.

McGruber writes:

In Atlanta, an electrical problem in a "Buss Duct" has caused the Sam Nunn Atlanta Federal Center to be closed for at least a week. 5,000 federal employees work at the center.

While many might view this as another example of The Infrastructure Crisis in the USA, it may also be another example of mismanagement at the General Service Administration (GSA), landlord for the complex.

The GSA has had many scandals and has been the subject of several Congressional Hearings, including an August 1, 2012 hearing titled "GSA: A Review of Agency Mismanagement and Wasteful Spending - Part 2". That hearing followed an $823,000 GSA employee conference in Las Vegas and a one-day-long $250,000 GSA employee conference in Crystal City, Virginia.

The closed Atlanta complex is named for Samuel Augustus "Sam" Nunn, Jr., who served for 24 years as a United States Senator from Georgia and whose daughter is the current Democratic Party nominee for a Georgia Senate seat.

• Re:A bad ... what? Re:A bad ... what? (Score: 2) by mrider on Tuesday July 29 2014, @02:37AM

  by mrider (3252) on Tuesday July 29 2014, @02:37AM (#74853)

  "Bus Duct" (with one "s") (see one manufacturer's home page) [eaton.com] is an alternative way to distribute electricity (alternative to "wire"). The idea is that you have an enclosed container with isolated electrically conductive bars (or bus bars) as opposed to running wire. This has a number of advantages:

  1. In multi-story buildings (think high rise), one has to worry about the weight of wire. A conductor large enough to handle large amounts of current is very heavy, and if you were to run it vertically more than a short distance, the weight of the wire would be a factor. You'd have to put in junction boxes periodically and clamp the wire - otherwise it would tend to want to fall back down through the conduit. The bus bar is periodically mounted via insulators to the back of the outer containing raceway, so it is self-supporting.
  2. When you have "wire" as your conductor, then tapping off turns into a cluster fuck in short order. Basically you either cut the wire and splice it back together along with any additional wires you tap in (less common), or else you strip a section of insulation and place the tap wire against that spot and use a split bolt [google.com] to join the wires. There are also a few products like the Kupl-Tap connector [lawsonproducts.com]. But regardless, it turns into a spaghetti mess pretty quickly.
  3. Wire is more subject to loosening from movement. Large current spikes can cause wire to jump somewhat (not a lot, but some). This movement can cause the connection to loosen over time. It's not uncommon to pay electricians to turn off the power and re-torque the lugs where the wire terminates. While bus bar is subject to the same stresses, the connections are going to be with bolts and split washers (or other similar mechanisms), and won't have nearly the tendency to loosen with time.
  4. Bus is made to more exacting specifications. Wire is more of an ad hoc solution, and so there are more opportunities for installers to do something wrong than with bus bar. With bus bar, you just line up the holes, use the supplied nuts/bolts/washers/whatever, and torque to specifications.

   

  We'll probably never hear what actually went wrong, although it would be interesting to find out. Bus is HIGHLY reliable. I would expect that there was some sort of work or changes in the building not too far in the past. Otherwise, it wouldn't be surprising to see the bus duct in use 50 years from now.

  --
  

  Doctor: "Do you hear voices?"

  Me: "Only when my bluetooth is charged."

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• Re:A bad ... what? Re:A bad ... what? (Score: 2) by VLM on Tuesday July 29 2014, @11:52AM

  by VLM (445) on Tuesday July 29 2014, @11:52AM (#74956)

  "Bus is HIGHLY reliable."

  But when you do manage to break it, its an unholy nightmare to track. Shorts are actually pretty convenient because you can see the damage, the problem is finding opens.

  Its like ripping out and reinstalling HVAC ducts to find a lost kitten. Its about that much work.

  I've never worked in a CO or data center using this tech but everyone likes to talk about it. Obviously 48VDC conductors are a bit larger than 440-3ph conductors for the same power level. I mostly worked in small long distance facilities (like less than an acre) so its possible this stuff is all over local loop serving centers (the building your home phone is probably hooked up to unless there's a SLC hut but I digress)

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  • Re:A bad ... what? (Score: 2) by mrider on Tuesday July 29 2014, @01:29PM

    by mrider (3252) on Tuesday July 29 2014, @01:29PM (#74994)

    Yeah. Finding intermittent opens are even more fun, because they can be at any joint. But that's pretty uncommon.

    --
    

    Doctor: "Do you hear voices?"

    Me: "Only when my bluetooth is charged."

    Parent