shop wiring using metal trough

[realbignutz]

hello, i have built a 60x70 shop and want to run wire on the outside of metal interior walls, now i am in mn. and am wondering can i just lay stranded or solid core in a metal trough mounted on the wall or would it have to be bx in the trough or would it just be cheaper to run wire in metal conduit? it is a farm shop so hopefuly wouldn't be considered a commericial building. any ideas or suggestion would be great.

 

[Modern Jess]

Can you clarify what you mean by "outside of metal interior walls"? I'm having trouble parsing that statement.

 

[Charles (in GA)]

Can you clarify what you mean by "outside of metal interior walls"? I'm having trouble parsing that statement.

He means a "gutter" installed on the inside walls of the building that the wires lay in. Raceway.

Big problem with anything open, is that it allows critters to access the wiring and eat at it, dirt to collect, etc. It needs to be in conduit, or other raceway, enclosed in any case.

Charles

 

[Modern Jess]

It was the "outside of interior walls" that I was having a problem with. In other words, outside outside? Seems like, in retrospect, he means the inside of the shop, not the outside.

That said, wall-mounted raceway is very much a viable solution, although spendy. I agree it has to be covered, though.

I'm currently installing Wiremold 4000 on the interior of my shop. Here you can see a bit of it covered, and a bit more (in the distance) that isn't (yet) covered.

 

[realbignutz]

hey thanks that is what i am talking about. i did some checking also and it is spendy compared to conduit. i think i will run bigger conduit. thanks for the replys

 

[W-Cummins]

hey thanks that is what i am talking about. i did some checking also and it is spendy compared to conduit. i think i will run bigger conduit. thanks for the replys

You can't just use larger conduit to replace wireway as you will quickly run into a nasty derating problem ( over 3 current carrying conductors ). So for a few circuits your ok but it quickly becomes a problem. What they (NEC) really should do is say at a specific fill ratio you do not have to derate. So if you ran say 20, 12 gauge wires in 3" conduit no derating would be required....

William....

 

[W-Cummins]

yeah,i think so,So if you ran say 20, 12 gauge wires in 3" conduit no derating would be required

Well, now all you need to do is to convince the NEC code writing committee to change the current code to allow this!

William....

 

[Fast Orange]

Wiremold is a bit on the costly side-
Why not run 4x4 metal trough with prepunched KOs ? It's somewhat cheaper than the wiremold,but gives you a very flexible wiring method. When you need to add or change a circuit, simply remove some covers,knock out the KO ,mount the new box and pull and terminate the wiring-no pipe to run -quick,easy and cheap to do ,once the trough is there.
The trough may not be as pretty as the wiremold,but it's alot easier to work with....