12KV Overhead Distribution

[steve66]

It looks like I will be designing a few thousand feet of overhead 12KV distribution.

New territory for me - I've done some underground, but around here the utility normally takes care of any overhead runs.

Obviously the NEC has some code requirements, but is there anywhere I can find standard specs or details for overhead distribution?

Just thinking in advance, I'm going to have to specify poles, conductors, cross arms, insulators, and grounded shield lines.

I'm assuming the poles will be direct bury wood. I'll also have to figure out the pole height, strength, and burial depth.

There will be several drops to underground distribution, so I'll probably have to specify taps and cutout switches also.

 

[mivey]

It looks like I will be designing a few thousand feet of overhead 12KV distribution.

New territory for me - I've done some underground, but around here the utility normally takes care of any overhead runs.

Obviously the NEC has some code requirements, but is there anywhere I can find standard specs or details for overhead distribution?

Just thinking in advance, I'm going to have to specify poles, conductors, cross arms, insulators, and grounded shield lines.

I'm assuming the poles will be direct bury wood. I'll also have to figure out the pole height, strength, and burial depth.

There will be several drops to underground distribution, so I'll probably have to specify taps and cutout switches also.

If you plan to do this DIY without experience (I would not recommend and would consider it irresponsible) then a good site to self-learn as much as you can would be: www.rd.usda.gov/publications/regulations-guidelines/bulletins/electric.

I recommend using a consultant but to each his own.

 

[wbdvt]

The other source more commonly used for utilities is the NESC, National Electric Safety Code IEEE C2-2012. If you haven't done this before I would agree with the previous poster. There are many factors to consider when doing line design. Some but not all are clearances, spans, conductor sag, conductor weight, ice and wind loading factors, angles with guying or push poles, conductor tension, pole class, etc.

I think you may want to contract out as the line crew building it will need a well designed plan to stake out and install poles, dress the poles, then pull and tension the conductor.

 

[bob]

It looks like I will be designing a few thousand feet of overhead 12KV distribution.

New territory for me - I've done some underground, but around here the utility normally takes care of any overhead runs.

Obviously the NEC has some code requirements, but is there anywhere I can find standard specs or details for overhead distribution?

Just thinking in advance, I'm going to have to specify poles, conductors, cross arms, insulators, and grounded shield lines.

I'm assuming the poles will be direct bury wood. I'll also have to figure out the pole height, strength, and burial depth.

There will be several drops to underground distribution, so I'll probably have to specify taps and cutout switches also.

Google 12KV Overhead Distribution DWGS

https://www.google.com/search?sourc...bution+DWGS#q=rus+specifications+and+drawings

General Requirements:

2 phase 15 kv fiberglass arm with pin insulators 15 kv instead of wood crossarm
1 pole cap pin with 15 kv pin insulator
no over head shield required. However, have seen middle phase used as a shield with ltg arresters installed and grounded on 25 kv system.
40 ft pole installed 6 - 6 1/2 ft deep
Depending on how long the tap is and if it is clear of trees, cutout switch may be omitted.
Fused cutout switch installed on UG riser pole. Must determine fuse size to coordinate with breaker and load.
Wire size will determine span length due to sag.
Suggest you consider #2 acsr conductor depending on load.

Hope this helps.
Bob

 

[Iron_Ben]

It looks like I will be designing a few thousand feet of overhead 12KV distribution.

New territory for me - I've done some underground, but around here the utility normally takes care of any overhead runs.

As a former poco guy, I agree with the first two responses you got. It's not rocket science, that's for sure, but if you're coming into this cold as you say, there's no way you'll be able to produce a first class set of plans. You might be able to cobble something together that can be made to work by a good line crew with some major changes in the field. Or maybe not. It's a risk I wouldn't take, stamping and signing something that I wasn't fully competent in and confident of. Though I've seen other engineers do it of course.

You might think in terms of getting some help from a utility engineer with line design experience. A couple of hours with such a guy would be well worth the few hundred he might charge.

And as for the NESC, we used it a lot. It was our bible in a sense. But it's even less of a design guide than the "not-intended-to-be-a-design-guide" NEC. Much less.

 

[bob]

[
QUOTE=Iron_Ben;1707975]You might think in terms of getting some help from a utility engineer with line design experience. A couple of hours with such a guy would be well worth the few hundred he might charge.
QUOTE]

He just did. 35 years worth. Free.

All you ever needed.
http://www.hubbellpowersystems.com/applications/distribution/ check the 2 phase bracket at the top of the pole.

 

[bob]

https://www.gdsassociates.com/downloads/

Down load dwgs

 

[mivey]

The other source more commonly used for utilities is the NESC, National Electric Safety Code IEEE C2-2012.

These are performance requirements but don't give you much help in how to design.

 

[steve66]

If you plan to do this DIY without experience (I would not recommend and would consider it irresponsible) then a good site to self-learn as much as you can would be: www.rd.usda.gov/publications/regulations-guidelines/bulletins/electric.

I recommend using a consultant but to each his own.

That's really between the Dept. of Professional Regulation and myself.

What I think is irresponsible is you thinking you can judge my capabilities based on a 6 sentence internet post.

I think I may send you a nice little private message and tell you what I think of you based on your 2 sentence reply, and your use of the term "DIY".

I have seen lots of posts from electricians and engineers that obviously had no clue, and were in way over their head. I don't hesitate to suggest that they get help, but I have never called anyone "irresponsible", nor would I call an engineer or an electrician a "DYI". :rant:

Some people are here to share and learn, and some are just here to inflate their own ego.

 

[steve66]

[
QUOTE=Iron_Ben;1707975]You might think in terms of getting some help from a utility engineer with line design experience. A couple of hours with such a guy would be well worth the few hundred he might charge.
QUOTE]

He just did. 35 years worth. Free.

All you ever needed.
http://www.hubbellpowersystems.com/applications/distribution/ check the 2 phase bracket at the top of the pole.

Thanks for the input Bob. I had forgotten about that poster.

 

[mivey]

What I think is irresponsible is you thinking you can judge my capabilities based on a 6 sentence internet post.

No judgment, just believing what you posted. How about reading what you posted from a remote perspective and think about what you were proposing sounded like.

I will be designing.
...
New territory for me
...
I'm going to have to specify poles, conductors, cross arms, insulators, and grounded shield lines.
...
I'll also have to figure out the pole height, strength, and burial depth.
...
I'll probably have to specify taps and cutout switches also.

I think I may send you a nice little private message and tell you what I think of you based on your 2 sentence reply, and your use of the term "DIY".

If that is what you think you need to do, then help yourself.

I have seen lots of posts from electricians and engineers that obviously had no clue, and were in way over their head. I don't hesitate to suggest that they get help, but I have never called anyone "irresponsible", nor would I call an engineer or an electrician a "DIY". :rant:

Yet this forum's moderators have put engineers on this site in a DIY box before. Whether or not you were involved I do not remember but I'll take your word that you would not.

Some people are here to share and learn, and some are just here to inflate their own ego.

I offered help to you and told you where to find good info. Take it however you like.

Sorry to get your knickers in a bunch but I don't always take time to be P.C. I would not expect someone of your history here to be so tender. Hope it was just one of those days. Best to you.