Feeding two 3-phase loads from a single pole?

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Steve-R

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What are the options & considerations necessary to take a new 3-phase feed from an existing pole that is already feeding one 3-phase load? I.e., one building is being fed 3-phase 12,470 from a pole, if you want to take a 2nd 3-phase feed from the same pole to a new padmount, what would standard practice dictate? Add a pole with separate fused cutouts for the new building? Add a crossarm to the pole if there is enough space? I know the NESC has clearance requirements between devices, what other considerations are there?

Could the existing cutouts be replaced with a cutout that would allow two connections on the load side (i.e., does such a cutout exist)? I don't see anything like that from Cooper but I'm still learning.
 
I would add a second pole to feed the new padmount. Putting two overhead to underground transitions on one pole is messy and extremely difficult to work. And that is if you can get the proper clearances in terms of safety and reliability. Just my opinion.
 
At the plant where I work we just backed up a pole and had the POCO connect there. A little more wire and conduit for the underground run, but cheaper than a new pole and easier for them. We were also going in a different direction than the original feed.
 
Unfortunately we can't back up a pole without boring under a road...this is the only pole on the correct side of the road.

wirenut1980 said:
I would add a second pole to feed the new padmount. Putting two overhead to underground transitions on one pole is messy and extremely difficult to work. And that is if you can get the proper clearances in terms of safety and reliability. Just my opinion.
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Thanks...opinions are exactly what I'm looking for here. You make some good points.

The existing feed is temporary and would be removed probably 18 months after the new feed was added. Would that change your thoughts?
 
Hard to say without seeing a picture of the pole and existing installation and which side the transitions would take place in relation to each other on the pole. Would you post something for us to look at? I would probably still not be comfortable with it, but maybe if there were stipulations that any work done there would be not be done live or something like that, and also have the understanding that reliability might take a hit in that 18 month period.

Speaking of which, who would be responsible for constructing and maintaining? You might run your scenario by them.
 
How far is the new load from the existing pole? or existing XF? Is the existing XF a loop with elbow arrestors inside, or was it built as a radial? For a temporary installation, I have added the new wire beside the old wire and ran one jumper from the cutouts to both terminations per phase. Are you looking to put each wire in a conduit by itself? or run three wires in one conduit? If the existing XF is close to the added load and it is built loop fed, you can run the new cable from one pot to the next.
 
Slack Span?

Slack Span?

If the pole is a dead end with down guy, having one riser on one set of fuses is about the limit. However, if the overhead line is slack spanned, you might be able to install fuses and riser on opposite sides of the same pole. I have also seen 12 foot fuse arm with six fused cutouts and two risers on the same side; not pretty but it works. If the transformers are internally fused, the option of loop feeding from one to the other exists. If the transformers are large or require the overhead fuses, loop feed is not possible.
 
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