attaching power cables on wall exterior

[al in wi]

what should i be considering?

I need to run 15 motor feeder cables along a wall exterior. I do have a lot of special circumstances. I would like to avoid a cable tray, cantilevered from the wall. This just seem to attrack bird's nest. also harder to replace cables.

So I am thinking of attaching them, stacked on top...maybe XX inches apart. Basically there is a motor every 50ft outside...so the feeder goes up and then goes horizontal, where more cables are. All the way to the end until all 15 of them enter the building.

I am thinking of using an MC cable or TC-type that is wet rated as well as sunlight/outdoor rated.

looking at the wall, you would see unitstruts and the cables are strapped to it, on one top of the other. (picture a musical staff)

any thing i am missing? or should be considering?

 

[eric9822]

Have you considered something like this?

http://www.pwindustries.com/products/centerspine/wsdt.php

 

[al in wi]

thanks ffor the link to the pwindustries

yes, i was thinking of that too. and i can group the feeders (3-4 feeders) per wall mount.

that could also alleviate my fear of heat dissipation. i was a bit concerned that if i stack the cables, without ample space in between, flush against the wall...i would experience some additive heat

this looks like a good start, thanks

anything/anyone else?

 

[benaround]

Al,

Have you thought about using 'bus duct' ?

 

[tkb]

How about these from Arlington.
http://www.arlcatalog.com/Flex/Steel Cable Hangers.htm

 

[LarryFine]

Okay, since nobody asked: Al, what size loads and conductors are we talking about?

 

[al in wi]

larry, these are big 500hp motors. most likely ill end up with 500mcm, or smaller with a medium voltage motor.

the arlington product looks good, tkb. thanks.

im sure i can find ways of hanging them.
bus duct was considered but would be a cost disadvantage.

i was more concerned of limitations on stacking, especially if there is a need for a heat calculation

 

[cadpoint]

larry, these are big 500hp motors. most likely ill end up with 500mcm, or smaller with a medium voltage motor.

the arlington product looks good, tkb. thanks.

im sure i can find ways of hanging them.
bus duct was considered but would be a cost disadvantage.

i was more concerned of limitations on stacking, especially if there is a need for a heat calculation

I'm sure I'm missing something!

Could you have two distrubition panels verse one?

Why don't you go underground?

I don't think that you sized your wire run yet; Annex C your floating around 3 to 3.1/2",(depending on what your exact choice will be)

(15 x 3") + (2" x 13) = 71"
conductor + gap

The longest one is 750' away. (?) That's just the outside run?

I don't think the Arlington product is meant for that size.

 

[LarryFine]

larry, these are big 500hp motors. most likely ill end up with 500mcm, or smaller with a medium voltage motor.

I have the feeling it might be better to see if you can move the distribution equipment closer to the loads.

A long feeder or two might be more economical and easier than running that many long individual circuits.

 

[kingpb]

I think you need to stick with the cable tray, which for that many and size of motors is going to be the general accepted practice.

If the Owner is not concerned with bird nesting, then you shouldn't either. You could always suggest covers to cut down on that issue.

Moving the SWGR closer is a good recommendation, but probably not practical.

Individual conduits would be cost prohibitive, and you would still need to rack them.

Stick with cable tray.