This technology could fundamentally change our relationship to electricity

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  • cpjcpj Senior Member Posts: 37,370 Senior Member
    tennmike said:
    cpj said:
    In my job I’ve never seen a 10%. Only 5
    Well, in some applications like yours, close enough ain't close enough! :D
    Actually it is! MOST panels will tolerate 15%! Which is a blessing and a curse. 
    Some let YOU pick the resistor value. Which is NICE when changing a panel. No hunting for the end  of line resistors. Which, took a couple of
    guys ALL DAY to find  the other day. They weren’t at the end of line, like they were SUPPOSED to be. 
    "I'm here for the guns, hunting, and skirt wearing men."
    Zee
  • hawk18hawk18 Senior Member Posts: 676 Senior Member
    I, luckily, never worked near a nuke plant, hence, less government oversight. Been in and out of the hydro units on the Umpquah, Rogue and Klamath rivers in Oregon and Northern Cal and much prefer low rpm. High speed turbines that are hydrogen cooled don't make me feel warm and fuzzy. As for color codes, I never used them that much outside the classroom. Don't regret it. 

    Hawk
  • tennmiketennmike Senior Member Posts: 22,278 Senior Member
    hawk18 said:
    I, luckily, never worked near a nuke plant, hence, less government oversight. Been in and out of the hydro units on the Umpquah, Rogue and Klamath rivers in Oregon and Northern Cal and much prefer low rpm. High speed turbines that are hydrogen cooled don't make me feel warm and fuzzy. As for color codes, I never used them that much outside the classroom. Don't regret it. 

    Hawk
    Hydrogen gas was used to keep the rotor cooled as it had less 'windage' than other gases. If that made you creep out, then what cooled the hydrogen gas would creep you out further. There was a big radiator in the top of the generator that used well strained water from the river flowing through it to cool the hydrogen gas. connecting tubes at each end, a WHOLE CRAPLOAD OF TUBES, were made of teflon tubing to prevent any problems with a short circuit of any kind. And the hydrogen pressure in the generator was kept at 10 psi minimum ABOVE the cooling water pressure so hydrogen gas would leak out rather than water leak in.

    Regarding the hydro plants, here's a bit of info that should give you a giggle. The Raccoon Mountain Pumped Storage hydro plant below Chattanooga uses an 'interesting' lubricant and sealing medium  for the pump/generator shaft setup. You'd probably never guess what it is; wet squishy horse manure in 50 lb. bags! Shovel it in and tighten down the gland around the shaft. Gives the generator floor a unique smell! It's biodegradable and considered a non pollutant.


    Non Sibi Sed Patriage (Not for self, but country)



  • hawk18hawk18 Senior Member Posts: 676 Senior Member
    Just re-read my earlier post and saw my mistake. Cooling the rotor instead of the turbine. We had several older plant step-up transformers cooled with water, always in plentiful supply. Amazing that a 50-60 year old transformer would still work with no water leaks. 
    Just got home from Spokane. Drove under bunches of 500kV lines coming from BPA's dams on the Columbia. And there was that one funky one with only two conductors. The 1000kV DC east/west  Intertie. 
    Sometime we should talk about main grid security from terrorists. 

    Hawk
  • tennmiketennmike Senior Member Posts: 22,278 Senior Member
    There IS NO GRID SECURITY from terrorists.............................The grid is bonehead simple to take down with nothing more than a .308 Win. and some FMJ ammo. Those ceramic insulators are strong, but brittle. Take down one phase and all three phases will be down as the breakers will open on a dead short on one. All that has to be done is shoot one of the insulators until it breaks; one to three shots will do it. On the BIG switchyard transformers there is an expansion tank on top with nitrogen as cover gas. The oil expands when the transformer heats up in operation and the excess goes to that tank. A hole in that tank will allow the oil/nitrogen gas to escape, depending on where the hole is, and the transformer protection circuitry will cause the downstream breaker to trip and take that phase off line, and that will cause the other two phases to be taken out also. The lines feeding that switchyard on those three phase lines will cause the feeder breakers feeding that switchyard to trip from high load imbalance, among other things. There are other things that can be done to take down the grid easily. Just depends on where the 'low hanging fruit' is as to switching equipment, and accessing it which is generally really easy.
    Non Sibi Sed Patriage (Not for self, but country)



  • zorbazorba Senior Member Posts: 15,987 Senior Member
    Loose lips sink ships... Just sayin'
    -Zorba, "The Veiled Male"

    Carry a 25 if it makes you feel good, but do not ever load it. If you load it, you may shoot it. If you shoot it, you may hit somebody, and if you hit somebody – and he finds out about it – he may be very angry with you. --Jeff Cooper
  • hawk18hawk18 Senior Member Posts: 676 Senior Member
    But, transformers and switch yards have people around. Transmission towers are often put together with bolts and 50 to 100 miles from civilization. A 12 inch crescent wrench and a cheater bar can do wonders. Three 500kV lines in the same corridor, topple the middle one into one of the others makes a big mess. 

    Hawk
  • tennmiketennmike Senior Member Posts: 22,278 Senior Member
    hawk18 said:
    But, transformers and switch yards have people around. Transmission towers are often put together with bolts and 50 to 100 miles from civilization. A 12 inch crescent wrench and a cheater bar can do wonders. Three 500kV lines in the same corridor, topple the middle one into one of the others makes a big mess. 

    Hawk
    You need to get out more. There are gobs and oddles of remote switchyards way out in the boonies controlled by orders sent over..................................wait for it................................................the internet! HA! Ain't nobody but turkey vultures and buzzards sitting on the transmission towers and pooping on the insulators. Speaking of which, saw a turkey vulture sitting on the end of the outside support structure of a 500Kv line at work. Right before they fly off they tend to 'dump ballast' and the insulators get pretty well coated. On this particular morning it had been foggy and the poop on the insulator had absorbed a lot of moisture. The turkey vulture pooped, the poop finally made the circuit, and the vulture got a 500Kv enema. Nothing but the sound reminiscent of a 5"/38 gun firing, and a LOT of feathers floating down to the ground. Some of his buddies were sitting close enough to get some of the blast from the arc and got blown up/fried. Tripped out one of the three outgoing 500Kv lines, too.

    On those remote switchyards, from my travels in the SW the border states have quite a few of those remote switchyards. You could cut off Southern California without even breaking a sweat.

    Find a good curve in the line, and a couple of wrenches on the outside legs of the tower will cause it to fall to the inside. Not a good place to be when stuff starts shorting out, though. That 161-500Kv to ground will light ya up!
    Non Sibi Sed Patriage (Not for self, but country)



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