new padmount service

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infinity said:
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How did the brown phase suddenly move from next to the yellow to next to the neutral?
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It looks as if they pulled the conductors in according to the yellow stamped X1,X2,.X3 right to left on the back of the can.Then they were swapd (in the vault) to make rotation or consistanty.
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As long as the phases are kept in close proximity with one another, I am wondering why it matters that the phases were swapped. By the way, have you noticed that you have lightning protection on the primary side of the loop feed transformer? :smile:
 
charlie said:
As long as the phases are kept in close proximity with one another, I am wondering why it matters that the phases were swapped. By the way, have you noticed that you have lightning protection on the primary side of the loop feed transformer? :smile:
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Charlie it is common for our company to put the incoming feeder on the H1A,H1B,H1C and the LA's on the H2A,H2B,H2C as in the picture. What seems uncommon is the use of concentric neutral cable on a delta primary, unless its a poorly terminated wire shield cable.

Rick
 
RUWired said:
. . . What seems uncommon is the use of concentric neutral cable on a delta primary, . .
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We do it all the time. The concentric neutrals are tied to our MGN and they are landed on the transformer ground ring (#2 Br Cu that rings the HV & LV compartments and hits the ground pad and ground rod, X0 is also tied to it.) Everything in the transformer is landed on that ground ring including the LA tails. :)
 
The lightning protection is a new requirment, and yes they are concentric neutrals. the phaseing in side is left to right brown orange yellow ABC so switching in the vault makes sense.
 
CIECO said:
Don?t ask me why but this utility supplies Y Y transformers. The picture is not from this install, But it is the same Y Y config.

View attachment 3030
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Almost every utility owned transformer in this area are wye-wye (in fact most are YG-YG) construction. You pay dearly for anything that isn't, and even then you may not get what you want.
 
I think 4 LB'S going thru wall would been just as easy. Do think its safe enough but question the brick. We must think of what could happen if we do get a short. Brick might just go flying.
 
iwire said:
I will add that the steel uni-strut clips are another violation considering this is an isolated phase installation. 300.3(B)(1) Exception / 300.20(B).

That is a very observant catch. But I'm wondering at what point does the PVC isolate the conductors from the Metal Strut Straps and Strut so that
it is not an issue. Who makes that determination? Its not like the conductors are passing through a completely Metal surrounding, The PVC is between the conductor and the metal.
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jap said:
iwire said:
I will add that the steel uni-strut clips are another violation considering this is an isolated phase installation. 300.3(B)(1) Exception / 300.20(B).

That is a very observant catch. But I'm wondering at what point does the PVC isolate the conductors from the Metal Strut Straps and Strut so that
it is not an issue. Who makes that determination? Its not like the conductors are passing through a completely Metal surrounding, The PVC is between the conductor and the metal.
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The PVC between the metal straps and strut will have little or no effect on inductive heating since the metal still separates the phase and neutral conductors. Change the strut to aluminum or fiberglass and the problem diminishes.
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I never thought about it that way.That's very interesting, Thanks.
 
I will tell you from my experience the kendorf and or the straps do not get hot even with a large load. You would have problems with a metal box, conduit or fittings. I have seen big problems with bushings.
 
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A company I used to work for ran a large temp feeder using PVC someone decided 'It's temp, lets run it isolated phase without following the rules.' :roll:

The customer called into the office when they smelled melting plastic because the strut clips where getting so hot they where melting the PVC conduits.

This was not good as the feeder was running equipment in a television station. :D Shutting it down was not an easy option.
 
CEICO,

Good thread, it's good to see how things are done elsewhere in the country. I've worked

20 years in the north east and 20 in the south west and the methods are like night and day.
 
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