Hi everyone,

I'm new to the forum but I've been lurking for a while, trying to figure things out on my own. But at the end of the day I'm a novice and figured I might have some luck asking my specific questions.

I'm trying to layout the wiring for my 1880s 36x46 barn. The previous owners brought a 100 amp sub panel (only 8 circuits) out there which they used to power some electric heaters and and a couple of lights that are no longer in use. The rest of the lights (there are only about 5 total, yes it's very dark in there) are actually on a circuit being run from the basement of my house. So my plan is to start over and try to to run everything in the barn from the barn panel.

Right now I'm only concerned with the first floor, and I've attached a 3d model I made along with a floor plan. Here's a little legend for the floor plan:

Blue dot: receptacle
Yellow dot: standard light fixture
Red dot: light switch
Green zone: the lights within this zone should be controlled by the switch it's attached to

Here are my primary questions:
1. How would you lay out the circuits for this first floor? I was thinking of using two for receptacles and two for lighting. If that makes sense, how would you group them together?
2. Wiring will have to be exposed, as it's all basically studs and siding. Is it okay to use Romex (that's how it is currently done) or do I have to use conduit? It will not be a living space and there will not be any animals in it, but down the road I will have a workshop in there with a small retail space.
3. Will 8 circuits be enough to cover the first and second floor?

I'm sure there are a lot of people who are going to say I should hire an electrician, and I probably will, but at this point I'm trying to educate myself about what is the best way to handle what I'm trying to do.

Thanks!

P.S. If that diagram doesn't make any sense, I can try to clarify or I can make a new one.

 

Welcome to the forums. Could you post a picture of the inside of your sub panel? And of the cover label? Generally you want lighting separate from receptacles. Any wiring you do must be protected, so any romex you run should be inside the stud bays. If this is not possible, the conduit would be required and you would run individual THWN wires through it, not romex. The number of circuits for lighting will depend on your potential total wattage. Are you using fluorescent, High capacity discharge, etc?

Planning a potential retail space, you may as well get the obligatory permit for this work. Plan ahead for all contingencies of receptacle use and do the placement now rather than later.

 

Commercial wiring will bring additional requirements. You will most likely have to meet minimum lighting levels and energy saving standards, provide exit lights as required by your local codes, provide emergency egress lighting, exterior lighting at exits, sign lighting circuit, display window circuit etc. Checking with a local contractor could be helpful as to the requirements in your area.

 

Thanks for the replys! Here are the pictures of the panel. Any advice you can give on how to divide up the circuits would be really great!

 

With only 13 fixtures, one 15A circuit should be able to handle all of the lights. Two 20A circuits for the 13 receptacles sounds about right for those.

Looking at your panel, it looks like it has 7 breaker spaces and that possibly two of them are taken up by a 240V breaker. Also, the panel label seems to be saying that only 6 of the spaces are available. Is that right or am I missing something?

It may be fine to use Type NM wiring (aka "Romex"), depending on the code adopted where you are. However, it is not OK to run Type NM on the surface of walls, unprotected, where it is exposed to physical damage.

You can use EMT conduit to protect it or to carry individual wires. You can use surface conduit such as Wiremold, with individual conductors. You can build wiring chases out of wood to cover and protect Type NM cables. There are a lot of options.

 

The panel will accept 6 full size single poles or 6 single pole tandems for up to 12 120 volt circuits.

 

Thanks for the responses! That information was really helpful, but it brings up a couple of more questions for me:

1. Out of curiosity, why are the first and last spots on the panel not available?
2. What's the easiest way to wire "zones" of lights on one circuit? There's probably an explanation out there, but I can't figure out how to search for it. What I mean by "zone" is, I would like to have a bunch of regular switches, but each one only controls a few lights at a time... in the photo I tried to represent this by the green areas. Can you do that on one circuit?
3. If the wires are inside the exposed stud bays is that considered protected? What about if they're 8-9 feet up and out of reach?

Thanks again!

 

You will probably be able to figure that out after you open the panel. One guess is that that's where the feeders connect.

Yes. Run the feed from the panel to each switch location in turn - a daisy chain. Feed the lights for each area in a chain from the switch for that area.

Individual conductors can never be left exposed. If you're asking about Type NM cables, the answer is no.In most jurisdictions, yes. Check with your local permit office.

 

Thanks so much for those answers, I think I'm finally starting to get a grasp on this!

A couple of more questions...

1. Since posting this I've added about 10 more lights to the design and I'm going to redo the upstairs wiring as well. There's also a bathroom and hot water heater that need power. At this point I'll be using up most if not all of the available circuits if I do not use tandem switches. Planning for the future, would it make sense to switch to a larger panel, perhaps one with 20 circuits? I was thinking something like this one?
2. When you say daisy chain, do you mean that I would use a pigtail at the switch to start that section of lights?
3. It would be ideal to have a switch upstairs that could shut off all of the downstairs lights... is that possible? How would something like that work?

Thanks again for all of the patience and answers!