Posted by Cydrome Leader on June 27, 2008, 6:59 pm
this sounds pretty accurate. The inrush current to even power on a small
distribution transformer is extremely high and would make any small
inverter just shut down thinking it was shorted out.
Posted by z on June 27, 2008, 10:11 pm
you guys are probably right.
I just remember several times during my wildland firefighting days seeing
down lines and hearing over the radio 'yeah they're not hot' and hoping
some asshole hadn't plugged in a generator somewhere down the line as we
began hitting the area with water.
Posted by Neon John on June 28, 2008, 1:55 pm
I'm a retired utility engineer and before that a lineman. IOW, a little
experience in this area.
A couple of comments.
ANY wire that you can't clearly see both ends of is considered hot until
rendered safe with grounds. As a lineman, I'd never touch even a downed guy
wire without my hot gloves on. If someone was telling you that a line was OK
because it wasn't hot, that person had a death wish for you. Even if the line
were dead at the moment, it could go hot at any second, either automatically
or because someone made a switching mistake.
Other comment: Water isn't conductive enough to present a shock hazard from a
fire hose or something similar even if the line is hot. It was a routine
practice to use fire hoses down live 500kV insulators at the power house
switch yard to remove crud buildup. I couldn't believe it the first time I
saw it but I learned that it is a routine procedure.
Now if you were using one of those back pack water bladders that the hotshots
use, different story. You don't want to "pee" on the power line!
John De Armond
See my website for my current email address
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
No one can be right all of the time but I'm getting close.
Posted by Solar Flare on July 1, 2008, 1:35 am
Better rethink that washing down 500kV insulators again.
Water is a good conductor of electricity unless it is absolutely pure.
The method used is pulsed water so there is no continuous path betwwen the
500kV line and the nozzle being held by the technician. They aren't "fire
Posted by z on July 1, 2008, 1:48 am
I've often wondered about 'wet water' -- its an additive we used in the
tanks. It kept the water from evaporating quite as fast and it would
stick and hold to plants better. Don't know if it made a huge difference
-- I think it was almost like a dishwashing liquid but no bubbles.
Wonder if current would travel through that better.
Always made me paranoid fighting fires around power lines. Some of those
large tower ones would glow red at night and begin stretching. Thats
when you had to boogie cos if they broke you'd get some nasty backlash