Conduit within temporary outdoor enclosure

[Alwayslearningelec]

Ok, we are going to have a pretty big( 30x20x15) temporary weatherproof walk-in enclosure built to house our switch gear and tranformers. I am just thinking of ideas, since this is a design build, to possibly save. Do the feeders within this enclosure need to be in conduit? I would imagine so but just checking. This is for a temp service. Thanks.

 

[RICK NAPIER]

If it would of been rquired if a permanant installation it would still be required 590.2 Except specifically modified in this article, all other requirements of this code for permanant wiring shall apply to temporary wiring.

 

[Alwayslearningelec]

If it would of been rquired if a permanant installation it would still be required 590.2 Except specifically modified in this article, all other requirements of this code for permanant wiring shall apply to temporary wiring.

Thanks Rick, I'll check it out.

 

[Alwayslearningelec]

It says NM or NMC cable shall be permitted to be used in any dwelling, building or structure etc.

Does this apply to my feeders within the enclosure mentioned above?

 

[markstg]

You may consider running cable tray. All feeders such as switchgear to MCC, MCC to transformer and panelboards are in cable tray. Some conduit drops do occur.

 

[Alwayslearningelec]

What about the NM and NMC? The cable tray is an option. Is that allowed per code? We will be gogin from switchboard to xfrms to distribution boards. I am talking about all those feeders. Thanks Mark.

 

[mkgrady]

If this temp building is going on a slab you might consider running all cables in a trench that would run under the switchgear. If the switchgear/transformer is free standing with typical open bottoms it might make the job simple. Based on your other posts I assume many of these cables will leave the building underground an go to riser poles. Using a trench might make that simple. I doubt using NM would be acceptable as it seems it would be subject to physical damage

 

[Alwayslearningelec]

If this temp building is going on a slab you might consider running all cables in a trench that would run under the switchgear. If the switchgear/transformer is free standing with typical open bottoms it might make the job simple. Based on your other posts I assume many of these cables will leave the building underground an go to riser poles. Using a trench might make that simple. I doubt using NM would be acceptable as it seems it would be subject to physical damage

So direct burial cables I assume? But then then what would have sleeves so when they pour our slab we would then run our cables through them?? I eould imagine some ofn the cables might be exposed a bit when coming up through the sleeves into our gear. THanks very much for the insight. I REALLY do appreciate it. There is nothing like gettinh electrical installation help from an electrician. You would be surprised how many people in the "office" are not knowledgable about some aspects of installation becuase they have not done it.

 

[markstg]

What about the NM and NMC? The cable tray is an option. Is that allowed per code? We will be gogin from switchboard to xfrms to distribution boards. I am talking about all those feeders. Thanks Mark.

You would use TC (Tray Cable).

 

[Alwayslearningelec]

You would use TC (Tray Cable).

Thanks....

 

[Alwayslearningelec]

You would use TC (Tray Cable).

So TC cable has to be used when we put it in tray??? Thanks.

 

[mkgrady]

So direct burial cables I assume? But then then what would have sleeves so when they pour our slab we would then run our cables through them?? I eould imagine some ofn the cables might be exposed a bit when coming up through the sleeves into our gear. THanks very much for the insight. I REALLY do appreciate it. There is nothing like gettinh electrical installation help from an electrician. You would be surprised how many people in the "office" are not knowledgable about some aspects of installation becuase they have not done it.

I would think any cable suitable for wet location would be good. THWN, XHHW. It won't be buried in dirt if you run conduits underground from the trench to the riser pole(s).

I don't think you need to have sleeves to go from a trench to the open space under the gear. The gear with open bottom is sitting on top of the open trench. Whereever the trench is not covered by gear you can make metal covers.

 

[markstg]

So TC cable has to be used when we put it in tray??? Thanks.

I'm not up on the exact wire size, but NEC allows 1/C cables above a certain size to be installed in cable tray. I've done this for 5KV cable. But then that makes you use conduit drops, whereas TC cable you can come right out the tray to equipment if the Cable tray is routed above the equipment. I've seen chase nipples used to enter the equipment, but prefer CGB's, seems it gives the TC cable better suppport than just hanging out tray and going into gear.

 

[Alwayslearningelec]

Ok, just reaching out once again although I recieved good feedback before. HAs anyone has distribution gear, transformers etc. in an outddor temporary enclosure before? Did you use pipe and wire to for the feeds. Seems impractical to support large conduits in an enclosure like this( 20x30). But this is a setup that I am sure is rare. Thanks