Thanks. it was a really sunny day yesterday (although it didn't even reach 40*F out) Today is just as sunny and it's about 53*F out now. We're getting some rain this coming week though and it's supposed to be in the 60's Monday and Tuesday!
Well I am absolutely not an expert in mid-voltage systems, but doesn't that bigger box look like a capacitor bank? Unless they are oil-isolated breakers. I always thought the lines were usually shut off using cutoffs.
It's a recloser, Ive installed these before. They are high voltage circuit breakers.
Cutouts are also used but these are used to re-energize the line after a fault. They are very helpful at isolating faults and quickly able to locate them and also can provide protection for linemen working on the energized primary. As for a cutouts prospective, It's more practical to have the line automatically reclose into a cleared fault then have to send a linemen out to refuse the cutout. Here we mainly use cutouts on side taps or transformers but we do have a few midspan cutouts in the system.
There are many versions of reclosers such as voltage switches, midpoint, sectionalizing, and radial.
How do they put the high-voltage lines so close to each other? I mean all the wires, and all of them are attached with a single metal piece, I have seen lots of lines like that, and I don't understand it.
How do they do it? How can they put the wires so close together and connect them? I bet with insulation but it doesn't look like much insulation..
The spacers are not metal, they are made of polymer and are insulated. The wire is also cover with a "guard". I've actually have gone to call outs where a branch has fallen on a wire and the lines were touching and nothing ever flashed over. This is a very common installation used by Mikes utility National Grid.
Is this setup more expensive than the normal setup? I have seen this in Denver, but it's not very common. I have also seen setups like this in kentucky, around Elizabethtown, and I bet they are prominent in a lot of places.
It's actually more difficult in my view to work on it energized since the lines are so close together. It's also much more difficult to put back up if it's been interrupted. As for cost, I think it is more expensive since you have to add a messenger wire to support the lines and I'm sure the spacers cost to.
Here the 11kV overheads are being replaced with ABC, as this has thick insulation so tree shorting is not so much of a problem. as well the cores are protected better, and have steel support wires as part of the conductors. A plus is they are easily identified in the scrapyards, unless you melt the aluminium down and cut the high tensile steel wire up into bits. Easier to install as you only have a single cable to pull, and do not need crossbars and such, just a slip on hanger per pole and line taps where needed.
I think the main reason they like this set-up is becuase they don't have to replace wooden crossbars (this pole is an acception as usually the poles with Hendrix Construction here don't have crossbars). Most poles with this style look like this
I like the good old crossbars. We had a few snap in two when Irene hit though. It happened on the main roads too so the neighborhood was in the dark for almost two days. Those big trees do a number on anything old. It appears all the lights around here survived though. I even saw a pole that snapped in two and the M-250R2 was fine! The refractor broke though so it has a FP lens now and tilts way up. It's on a nice sturdy 6' tapered E arm.
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Cutouts are also used but these are used to re-energize the line after a fault. They are very helpful at isolating faults and quickly able to locate them and also can provide protection for linemen working on the energized primary. As for a cutouts prospective, It's more practical to have the line automatically reclose into a cleared fault then have to send a linemen out to refuse the cutout. Here we mainly use cutouts on side taps or transformers but we do have a few midspan cutouts in the system.
There are many versions of reclosers such as voltage switches, midpoint, sectionalizing, and radial.
How do they do it? How can they put the wires so close together and connect them? I bet with insulation but it doesn't look like much insulation..
I guess this setup is safer?