Running Electrical Wiring in Metal Building

[jbtx]

Our 30x30 workshop is going up as we speak. It's a metal building with R-Panels on the exterior, then 4" insulation behind the girts/purlins, followed by R-Panels 92" high on the interior of the shop.

The interior R-Panels are obviously installed on top of the girts/purlins, so I am wondering how to run the electrical wiring for the outlets. A recommendation was to have an outlet every 3 feet, but that seems to be overkill, so I'm going with placing them every 5 feet or even further apart.

Anyone have any suggestions on how to run the electrical using those panels? Once they are up, do I even have options running the wire behind the panels?

 

[Knight511]

I used T1-11 in my shop, so not exact but close enough. I installed 2x3s horizontally on the last layer of the frame (yours may need to be vertical). The 2x3s provided enough space to run my EMT (I used 1") between the T1-11 and the metal frame of the shop. I ran EMT because I used THHN wire (conduit is required), and I wanted the wire to have some protection as well (I wanted to use conduit regardless of wire, so I chose THHN because it is easy to work with in conduit).

 

[jbtx]

I used T1-11 in my shop, so not exact but close enough. I installed 2x3s horizontally on the last layer of the frame (yours may need to be vertical). The 2x3s provided enough space to run my EMT (I used 1") between the T1-11 and the metal frame of the shop. I ran EMT because I used THHN wire (conduit is required), and I wanted the wire to have some protection as well (I wanted to use conduit regardless of wire, so I chose THHN because it is easy to work with in conduit).

The contractor putting the metal building up is great to work with, so I'll see what he'll let me do putting 2x3s or 2x4s on before he installs the interior panels. I see what you are saying with running 1" EMT.

I also just looked at the schematic of an R-Panel and it seems that there is a vertical cavity that one of the raised sections of the panel creates. The one I looked at is 1 1/4", which seems like would be enough to run a 1" EMT down an outlet.

 

[readhead]

If you know where your panel will start it is very simple. Use 4S box's and MC cable. Get the box's close to the flat by the lap but leave some slack in the cable and screw the box to the girt that is hopefully at 4' above the floor. If there is no girt the box can be fastened right to the panel. The flat parts of the panel are 1' on center. Have the electrician on hand or do this step if you feel comfortable and locate the box in the low closest to the lap. Cut a hole for the box in the panel. Remember that slack you left in the MC cable? Now you can move the box to the hole and fasten everything together.

 

[alfredeneuman]

All conduits are subject to amp derating that more than 3 wires (More than 9 wires will trigger a 50%
reduction).
A clearance hole for 1" conduit is 1-3/8".
3/4" is 1-1/8".
1" is a PITA to work with
I'd suggest running 2 (or more) 3/4"

 

[cannuck]

I built my current 26 x 39 metal shop 38 years ago, and decided then to go with all surface mount with EMT. Very happy as I have done a few changes over the years that was easily accommodated by pulling back through existing conduit or just adding some new stuff. I have mostly steel structure so most clips are in 1/8 or 3/16 with self drilling, self tapping screws. When on aluminum inner skin, though nutserts work best for me.

 

[dcg9381]

I'm doing this now on an extension. We screw 3/4 ply (12" strips) into horizontal purlins, then run all the power through PVC conduit to boxes. We're running 2 circuits through 3/4" PVC and have 2 runs of PVC in parallel.

You can never have too many outlets..

 

[jbtx]

Everyone, this is such tremendous help and very much appreciated! The electrician has not come out yet to review, but there is so much here already that I think I have a solid plan in place.

 

[jbtx]

I'm doing this now on an extension. We screw 3/4 ply (12" strips) into horizontal purlins, then run all the power through PVC conduit to boxes. We're running 2 circuits through 3/4" PVC and have 2 runs of PVC in parallel.

You can never have too many outlets..

I think what you are saying is that you're running the conduit parallel on top of one of the horizontal 12" strips.

Are you putting the R-Panel siding in yourself? My dilemma is that between the contractor putting the panels in and the electrician, I'd have to have the prep-work coordinated. I'll give this a bit more thought and see how that could work for us. Appreciate the input!