resources for electrical planning

[Thomas Crawford]

Could anyone recommend a resource for planning the fanout from my subpanel on a detached shop? I have a handle on the code portion, where to tack it down, drilling through studs, etc etc. What I'm looking for is 'best practices' in the context of a vaulted ceiling, where to locate the subpanel, tips to minimize cost, etc. It's a basic 20x28, hip roof, vaulted ceiling.

Thanks in advance. Will hopefully be starting a thread soon with my shop build.

[Jim Becker]

Subpanel location would typically be "in the vicinity" of where the service enters the building since that reduces the amount of "really big wire" (technical term... ) that has to be used which further reduces cost. However, that may or may not necessarily be optimal from a practical standpoint for a shop setup in some cases, such as with the vaulted ceiling you mention since you don't have as much choice for hidden and/or direct pathways to get to various places in the shop. The floor plan of your shop will play a role, too. If you're going to keep the majority of your machinery in one location and use other locations for less electrically intensive work, then having the panel closer to the machinery area means less wire to get the circuits placed to support those tools. Depending on the number of circuits, that could favor a longer feeder vs more distribution wiring. One other thing relative to machinery...if you are able to plan up-front where the tools that will be somewhere in the middle will be, you can then plan for the supporting circuits to travel in the floor. That might mean in conduit embedded in concrete or under the floor in the case of a crawlspace or basement. There are so many things that can affect how best to wire things up and your actual shop design is going to affect them.

So help us help you...what are you thinking about relative to your shop footprint, arrangement and construction type? It will be a lot easier to help you accordingly.

[Thomas Crawford]

thanks Jim, I'll get some screenshots of my sketchup file.

[Thomas Crawford]

[Thomas Crawford]

[Jim Becker]

Thomas, for a shop of that size, it almost doesn't matter where the panel is, so most likely it will be close to where the service drop from the source enters the building. Do note that there needs to be space maintained in front of the panel by code, so that will affect anything of a "permanent" nature as well as you practically need to have ready access to it. Therefore, you'll want to spot it in a place that works best for that. The corner near the door might work for that.

That big tool with the green cover and colored "ball bearings" is interesting... LOL

[Thomas Crawford]

The shortest run for the "big wire" is 75'. Unfortunately its also where I want to put the sink, as its also the shortest run for plumbing. So I'm thinking the panel on one of the walls without windows. Looking at 80-100 amp current carrying capacity over 100'.

The pool table is a long story and it needs to be there. It will have a hard cover and can double as assembly/painting/finishing space.

The sawstop will be a 36" on a mobile base. I think the sketchup model is the 52", so mine will be touch narrower.

Dust collector likely a 3HP dust gorilla.

I already own the bandsaw and jointer/planer.

drill press and lathe would be future purchases.

Already have the 8' Roubo and dutch tool chest.

The only other thing not pictured would be a mini-split AC and heat pump combo.

[Thomas Crawford]

Thomas, for a shop of that size, it almost doesn't matter where the panel is, so most likely it will be close to where the service drop from the source enters the building. Do note that there needs to be space maintained in front of the panel by code, so that will affect anything of a "permanent" nature as well as you practically need to have ready access to it. Therefore, you'll want to spot it in a place that works best for that. The corner near the door might work for that.

That big tool with the green cover and colored "ball bearings" is interesting... LOL

So maybe the wall next to the window above where the J/P is? I'll have to check on the order of the foundation and flatwork, not sure if they were going to do that all at once.

[Jim Becker]

Yea, that would be ok as long as you can get to it. Don't have the tool sitting there when you go for your inspections.

[Peter Christensen]

If you have picked out the electrical contractor or are at least interviewing some you can ask where they recommend the service coming in to make their life easier and to minimize the cost of wire runs. If the panel is in the corner beside the lathe a lot of the wires can be run horizontally from the panel and fewer run over the top to the opposite wall whereas if you have it in the corner by the door almost everything has to be run up and over.

[Robert Engel]

If you have picked out the electrical contractor

This is the key. They know the code and it will save you a ton of time

[Jim Becker]

If you have picked out the electrical contractor or are at least interviewing some you can ask where they recommend the service coming in to make their life easier and to minimize the cost of wire runs. If the panel is in the corner beside the lathe a lot of the wires can be run horizontally from the panel and fewer run over the top to the opposite wall whereas if you have it in the corner by the door almost everything has to be run up and over.

I agree...and in this case, "up and over" isn't really an option since it's a vaulted ceiling. Everything needs to run in the walls or through the floor.

[Peter Christensen]

My shop roof is a scissor truss so vaulted. As expected the wiring for the lights have to go up there. It all depends on how it is going to be built and insulated and the OP hasn't said what the shop construction will comprise. Easy if wood framed and not if concrete block.

[Thomas Crawford]

I'm doing all the electrical myself. One reason I was considering the back wall was to minimize the amount of wires I'd have to put through the corners. Otherwise I was hoping to split some of it up and high and some near the floor.

I had not thought about running through the floor other than maybe putting a floor plug out in the middle where the TS is.

[Thomas Crawford]

My shop roof is a scissor truss so vaulted. As expected the wiring for the lights have to go up there. It all depends on how it is going to be built and insulated and the OP hasn't said what the shop construction will comprise. Easy if wood framed and not if concrete block.

Wood framed, spray foam insulation.