Separate circuits or sub panel?

[bullnerd]

Hopefully this is my last electronical question!

I am eventually going to have some electrical devices in a lean-to behind my shop.

I'm guessing, at least, Compressor, dust collector, mini-split AC, And I'm probably forgetting something. Oh maybe a phase converter depending.

Would it be better to run EMT with individual circuits, or run a separate sub panel?

I have a fairly empty 200 amp main, approx. 40' away at the front of the building.

Thanks guys couldn't have done it without you. Well I could, but I probably would have gotten shocked even more than I did.

 

[wyliesdiesels]

you could price out the cost difference between individual circuits and putting in a sub.

It may be cheaper to put a sub then run circuits off of that.

 

[bullnerd]

I have a lot of 12ga stranded already.

Can you take a WAG at what wire I would need to run for a sub?

Probably be a 3hp or so.

 

[75gmck25]

Assuming I understand the code correctly (maybe not), you can run one 20 amp MWBC circuit (with a 12/3 you get two 20 amp ciruits), or you can run larger gauge wire and install a subpanel. You are not allowed to run multiple individual circuits from your main panel to a detached building.

As far as wiring options for a subpanel, you need to price out your choices for wet rated wire, which I assume you will run in conduit. Many folks use 2-2-2-4 AL MHF just because its easy to find and relatively inexpensive. You probably don't need that big a wire, but when you compare the prices to 6/3 copper or other larger gauge alternatives in copper, it might be very similar. If you buy the right wire you don't have to run it in conduit, but it just seems to make sense in case you want to change something later.

Bruce

 

[slow]

Other factor to consider, is how many of those devices you wish to add need a disconnect? having a sub panel within line of sight may prevent the extra cost of disconnects.

 

[pattenp]

…. You are not allowed to run multiple individual circuits from your main panel to a detached building.

Bruce

I'm thinking he's wanting to run circuits from a panel that's in the shop to a lean-to attached to the back of the shop, so it's not a detached building. That's what I was thinking...Maybe, maybe not???

 

[strutaeng]

I'm thinking he's wanting to run circuits from a panel that's in the shop to a lean-to attached to the back of the shop, so it's not a detached building. That's what I was thinking...Maybe, maybe not???

That's what I was thinking too.

If you already have #12 stranded, then it's just the cost of 40' of EMT and misc. elbows, etc!

I think the cost of running circuits is in the copper? Seems like a no-brainer if you already have the wire laying around, no?

How much wire do you have? Enough to run (4) 20A circuits?

 

[sberry]

A compressor of any size will need a piped wire of 10. I just talked a guy in to a sub, partly cause he was gonna run out of spaces and its a decent building, tall too. It was 85 ft minimum wire across it, I figured buy 1 cable and be done going across it forever. It also saved the disconnect cost for a couple machines. I been using a 12 space from Homeline, 36$ I think and 3.50 a single pole breaker. You can get 2 2 4 6 for the cost of a number 10 copper.
There are no doors on that wall, can wire sideways at any time. The 12 space is in a bigger box than the 6 or 8.

 

[bullnerd]

Yes, lean-to, not separate building. Basically outlets/disconnect on back, outside wall of metal building.

I have a lot, I think 250', I'd have to look, of 12 wire.

The compressor I'm looking at says it can run on a 20.

The reason I ask is because I want to get the insulation done in the attic and this is the last thing that may have to run up there before I screw the cover back on.

If I run EMT, I will go inside, If I run a larger wire to a sub, I will probably go through the attic.

Anything special breaker-wise to in the main panel to run a sub?

 

[wyliesdiesels]

Yes, lean-to, not separate building. Basically outlets/disconnect on back, outside wall of metal building.

I have a lot, I think 250', I'd have to look, of 12 wire.

The compressor I'm looking at says it can run on a 20.

The reason I ask is because I want to get the insulation done in the attic and this is the last thing that may have to run up there before I screw the cover back on.

If I run EMT, I will go inside, If I run a larger wire to a sub, I will probably go through the attic.

Anything special breaker-wise to in the main panel to run a sub?

whats the HP rating on the comp?

 

[bullnerd]

Leeson, 3hp.

Im guessing it would make sense to plan for the future and be able to handle 5hp?

 

[alfredeneuman]

Keep in mind that any more than 9-#12 current carrying wires in 1 conduit, because of the derating factor, will cause the #12s to use a 15A breaker instead of a 20A.

 

[sberry]

Also,,, 250 ft of wire may seem like a lot but it will go fast just on the ends. (Its not much.

 

[bullnerd]

OK, I finally took a look, I have 500' of 12 and 500' of 14. Only used a small amount of 14 on the lights.

AC-240
compressor-240
dust collector-120
Spare?- ?

Can I just run the 12 I have for 2 240 circuits and buy a small roll of 10 for the compressor circuit?

If I was going to run a sub panel, What wire would you suggest? (this would go through attic)

 

[mike93lx]

I would just run 2-2-2-4 AL SER, assuming it is all interior and not somewhere subject to damage. Put in a 12-20 space panel and breaker it at 90A or less.

around me, the wire is 1.50/ft. 4-4-4-6 is only 0.27/ft cheaper, so I don't think it's worth going smaller

I would not run a bunch of separate circuits just to use up wire...that's a waste. There will be a use for it at some point, or you can sell it. All that conduit, fittings, and labor will add up quickly too.

 

[bullnerd]

Thanks Mike,

I wasn't going to run the wire just to use it up. Just because I have it. But if I need to buy heavier wire for the compressor anyway, its not worth it.

I have a large conduit going from the panel to the ceiling,(pic) then open through the attic to the other end of the building, then I can go down through the wall or out and down through conduit on the outer wall.

How do I hook this into the main panel? Is there a special breaker for the larger wire?

Whats a 12-20? This is the same as SBerry was talking about right?

Would this work? I think my main is homeline.

https://www.homedepot.com/p/Square-...Main-Lug-Load-Center-HOM612L100RBCP/100143240

 

[mike93lx]

Just meant a panel with at least 12 circuits, but I would shoot for something around 20.

I would not use what you linked, too small IMO. This is more like what I would use. Your friend has shared a link to a Home Depot product they think you would be interested in seeing:

Square D Homeline 100 Amp 20-Space 40-Circuit Indoor Main Breaker Plug-On Neutral Load Center with Cover - Value Pack
https://www.homedepot.com/p/Square-...th-Cover-Value-Pack-HOM2040M100PCVP/204836397

If you have conduit, you can run individual conductors, I think Al XHHW, but check that.

You just use a regular breaker at the main panel. Check the wire manufacturer's specs to see if you need anti oxidant paste (assuming you are using Al wire)

 

[bullnerd]

Sub panel will be outside, but under a roof.

Conduit in my pic only goes through the metal ceiling and ends about 2" up, doesnt run the whole distance.

I don't really need 12 circuits. 4 would probably work, 6 would be better. 2-240 and 1 or 2 120 outlets.

 

[sberry]

12 cost about 15$ more than 6 or 10$ more than 8 and is in a bigger box.

 

[mike93lx]

Sub panel will be outside, but under a roof.

Conduit in my pic only goes through the metal ceiling and ends about 2" up, doesnt run the whole distance.

I don't really need 12 circuits. 4 would probably work, 6 would be better. 2-240 and 1 or 2 120 outlets.

Make sure you get an outdoor rated panel.

Get whatever panel size you want, I just try to plan for the unknown

 

[UglySign]

I don't really need 12 circuits. 4 would probably work, 6 would be better. 2-240 and 1 or 2 120 outlets.

I said the same thing once only to find out I nee....

 

[bullnerd]

This will be outside under a lean to, only thing back there will be ac, compressor and dust collector.