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44kv
08-23-2006, 06:37 PM
on my way home today i was looking at the local co-op here (energy unitied) and i have always wondered why is the neutral always above the high side of the tx's? do you ever have any problems with that saftey wise?

Patriot
08-23-2006, 07:18 PM
Above the high side? It is usually just above the secondary lugs. On a 45 degree, 4" below the neutral. I think that is REA spec, 7" down on a deadend, and 4" on a tangent. It has been a few years, but that is how I remember.

Linemanblood
08-24-2006, 12:34 AM
I think it all started years ago with the REA's setting short poles which is why they cram everything together trying to save money on short poles since its supposed to be nonprofit outfit

thrasher
08-24-2006, 08:11 AM
There are a couple of reasons for mounting the neutral near the top of the transformer tank. The main one is that it doesn't matter whether the pole has a trans or not the neutral never moves from the day it was built. From a safety viewpoint the tank of the transformer is grounded so my question is does that create a problem for you investor types with several square feet of grounded steel above the neutral. The other reason for the neutral never moving is it simplifies the spec book and makes it easier to train groundmen to frame a pole on the ground. And yes it does mean that sometimes we can get away with a five foot shorter pole than the investor type specs.

44kv
08-26-2006, 06:01 PM
ive never had a problem with the tx above the neutral everything hot is above the high side everything grounded is below the high side. on co-op i just seen that high side stinger running right be side ( not 5 inchs from ) the neutral. just was wondering about that.

DuFuss
08-26-2006, 06:42 PM
I believe the spec is 7 1/2 below. I'm not totally certain on that. I do 8 inches unless it's a three phase pole with a cross arm then I go 11. Clears up the lightning arrestor if it's a porcelain 25kv (19?). Wished everyone would do pollys, they are much shorter and have no trouble clearing up on any crossarm braces.

wudwlkr
08-28-2006, 07:19 AM
Current RUS (Co-op) specifications for single phase transformer installations call for the neutral to be even with the bottom of the transformer lid when mounted on a tangent pole and 3 inches above the lid on a dead end pole. RUS spec sheet G1.1G.

mrgrowl791
08-30-2006, 08:09 PM
Top pot bolt is bored 12" down from the neutral tangent or dead-end.