Help with EMT

[01Bullitt82]

Hello Everyone, ive been looking through the journal and have learned alot. First time poster, though. I just had a 30x45x12 steel building built. I want to run EMT for my power. The problem im face is that the vertical columns on the 45' sides have double columns, and the horizontal braces are only signal. Also the front and rear 30' sides are single columan. What would be the best place to mount my boxes with the least amount of bends? while maximuming space. I currently have the boxes mounted with magnets, just to see what i was working with. If i put them on the horizontal brace, i feel like its a lot of bends to go around all the double columns. If I mount to the front of the double columans, the conduit is straight but then im losing 2.5-5" of space between the conduit and wall. I would preciate any advice from anyone who has dealt with this before. Picture for reference.

 

[LXCam]

Looks like you just need to get proficient at bending saddles. Or go vertical and into another box support in the ceiling space with a run paralleling your wall but you’d need to support that box as well.

Saddles aren’t that hard. Do you know the 30 degree rule for bending an offset?

 

[sparky 1971]

I would, and do, run the EMT high, right below the kicker braces from the wall to the ceiling. Set a box wherever you want a receptacle and run a conduit down the post to that box. It will take more conduit but be faster and look a whole lot better than having 500 offsets.

 

[matt_i]

There is also a tee (and LB and other related conduit bodies) which are made with a smooth bore for direct adaptation to EMT this no male thread adapter is needed. Not hanging out everywhere but would save some work and other parts if you are putting in quite a few tees.

The handbook which comes with the hand bender has everything you need although it takes a mild amount of study. There are 3 marks on the bender radius, notch, star and arrow to assist with lining up the various bending methods. When you lose the handbook you just look up the instructions online a few years from now.

 

[JohnX14]

I would, and do, run the EMT high, right below the kicker braces from the wall to the ceiling. Set a box wherever you want a receptacle and run a conduit down the post to that box. It will take more conduit but be faster and look a whole lot better than having 500 offsets.

I like running the EMT high and dropping down for a number of reasons. That's how I'd do it too.

 

[LXCam]

Now that I'm not on my phone and can see the framing. I'd use bracket boxes on the side of the columns then up to a T or another box mounted to the truss. The use these for meeting your strapping requirements.

https://www.zoro.com/nvent-caddy-hanger-conduit-emt-pipe-use-12-in-34-in-steel-electro-galvanized-812mb18a/i/G2918115/?utm_source=google&utm_medium=surfaces&utm_campaign=shopping feed&utm_content=free google shopping clicks&campaignid=23605674842&productid=G2918115&v=&gclsrc=aw.ds&gad_source=1&gad_campaignid=23605674842&gbraid=0AAAAADw3hZdh5mXPAxT-TJ42Edsz8sNCT&gclid=Cj0KCQjwnIDUBhDrARIsAJDGwSuvVh7xOYDsm4UvNkQ41f_fQDSJqfTwegb62jafJN5GT0babe6lK3MaAvuFEALw_wcB

 

[dscheidt]

Bending saddles isn’t hard. Don’t let fear of them lead you to a layout that you don’t want. You will be living with it for a long time.

Figure out where you want boxes, then figure out how to pipe them up, using the least material.

Vertical drops will likely use more pipe, more boxes, and more wire. How much depends on the layout. It would take me longer if I was working off a ladder, but it might be faster for you.

 

[01Bullitt82]

All good suggestions, thank you. I did think about running it high and dropping down but that seemed like alot of conduit and wire. If I make bends thats about 8 columns to go around on each side. I guess I just need to decide on if I want to use more material and save time or use less and take more time.

 

[matt_i]

The top "trunk line" is a fairly future proofed solution if you have enough diameter in the trunk. Yes this costs more now but you have the wireway 95% built for any future needs. Without sufficient diameter a person would have to start from the (sub) panel again running wireway. A building like that isn't very conducive to NM.

 

[01Bullitt82]

I planned on running 3/4 conduit, is that big enough for a "trunk line" if I go that route?

 

[Dagny]

If you put more than 3 current carrying conductors you have to derate them so don't get all excited about running everything in one pipe.

 

[dscheidt]

If you put more than 3 current carrying conductors you have to derate them so don't get all excited about running everything in one pipe.

yes, but you derate them from table 310.16, which for most situations means THHN 10 awg and smaller carries what you expect it to be from 240 whatever.

 

[WildBill]

I also vote for running above and dropping down, that's what I did and it was fast, easy, and easy to add stuff afterwards. I also put boxes up for light receptacles and drop cords etc along the main trunk at every other roof truss. A duplex switched receptacle and a duplex always on in a double extra deep box at each location. I ran cords from them along the ceiling framing to LED strips and light fixtures, the LED strips are using one of the always on as they are app controlled. Has worked out really nice. If you look around you can buy bulk amounts of boxes for way less than Home Depot, I think I got mine from Ebay.

 

[rabidsquirrel]

If you put more than 3 current carrying conductors you have to derate them so don't get all excited about running everything in one pipe.

That's still nine 12 awg current carrying conductors though...

 

[mm08822]

If you put more than 3 current carrying conductors you have to derate them so don't get all excited about running everything in one pipe.

7-9 CCC's requires derating to 70%. Using the 90C column for cu thhn derating let's #14 be ocp'd at 15a, #12 at 20a, #10 at 30a.

Above 9 CCC's is when it starts to impact ocp value.

I'd worry more about box fill.

 

[mm08822]

I also vote for running above and dropping down, that's what I did and it was fast, easy, and easy to add stuff afterwards. I also put boxes up for light receptacles and drop cords etc along the main trunk at every other roof truss. A duplex switched receptacle and a duplex always on in a double extra deep box at each location. I ran cords from them along the ceiling framing to LED strips and light fixtures, the LED strips are using one of the always on as they are app controlled. Has worked out really nice. If you look around you can buy bulk amounts of boxes for way less than Home Depot, I think I got mine from Ebay.

Ceiling recepts even for lighting requires gfci protection.

Ceiling outlets that get hard-wired to do not.

 

[01Bullitt82]

You guys are talking over my head now. Lol. I do have a electrician to help me with the technial stuff, but I was trying to get a head start on the lay out. The plan was to have 4 outlet on each side wall, three on the back wall and 3 in the middle of the trusses for the 6 high bay lights to plug into. I thought when a led light goes out it would easier to replace it by unplugging it and pluging a new one in.

 

[cannuck]

If you have enough room over the diagonal braces to me this is screaming for cable trays. Personally, I would have 120V 20A outlets on every column, plus 240s as needed.