40X60 Electrical Plan

[AuroraSC]

I'm just finishing up on my 40x60x14 pole barn construction and will be commencing the electrical work shortly.

My hope with this thread is to make sure I make good choices and spend time and money wisely. Suggestions or recommendations welcome.

The slab has (2) 1-1/4" conduit for main power and (1) 1" conduit for low voltage needs. I will only be utilizing (1) of the power conduits initially. The other is for expansion purposes.

I'll be bringing in Cat6 for internet and security.

As for running the wire in the shop, my electrician friend is helping me out on the weekends. He is pushing me to run MC wire, whereas a friends dad says to run hard conduit. What is a good way to make that decision?

125A Breaker from Main Panel (In Home Garage)
https://www.amazon.com/gp/product/B002KGFTXU/?tag=atomicindus08-20

3GA Wire (From Elec Supply)

200A Square D Shop Panel
https://www.amazon.com/dp/B00NO2533U/?tag=atomicindus08-20

Leviton 20A Dual Receps
https://www.westsidewholesale.com/leviton-16352-e.html

Leviton 50A Receps
https://www.amazon.com/gp/product/B00004YUNT/?tag=atomicindus08-20

GreenTek 110W High Bay LED's
https://greenlightdepot.com/collect...0w-with-lens-and-w-o-lens?variant=36041819012

Cat6 Cable
https://www.monoprice.com/product?p_id=8103

 

[Stuff]

Your electrician friend seems to be confused. 3 gauge copper is only good for 100 amps.
MC provides minimal protection and bends/looks messy. EMT is a lot more work.

 

[polexican23]

i dont know how your electrical inspector is, but if i could do it all over i would have do the very minimal electrical to get final. once the permit is over, then go nuts.

 

[alfredeneuman]

By Code, you're only allowed a single feed (the panel) to an outbuilding such as a pole barn, so the conduit to be used for future power needs is a no-go

 

[colomboj]

If you run conduit you can always pull the wire out and pull in bigger wire if the need should arise. Personally I ran PVC under slab to each and every outlet so I can make any of them into anything I want at any time. It's also incredibly cheap to do PVC under slab so more money for beer and tools!

As previously stated #3 is only good for 115 amps Table 310.15(b)(16) so that 125 amp breaker is a no go.

I don't understand the purpose of the second conduit thing. You could always pull a sub panel off the shop panel if you needed more space. If you're trying to get more ampacity for some future stuff I would strongly encourage you to just do it right the first time and run some larger wire 4/0 4/0 4/0 URD is stupid cheap and can be thrown right into a trench along with a #2 for ground and you have 200 amp rated wire... albeit it's aluminum. Also 200 amp panel on a 100 amp breaker... if your plan is to just run another set of wires and make it a 200 amp service at a latter time... think again. 310.10(H)(1) requires those feeders to be 1/0 or larger before you can parallel them.

Also Cat 6... You probably don't need it Cat5e is plenty good for the average home user, and if you're running it underground I would suggest a flooded core cable, and to put surge suppressors on both ends to prevent equipment damage.

I'm not a fan of HO panels I prefer QO but at least it's square d!

 

[colomboj]

i dont know how your electrical inspector is, but if i could do it all over i would have do the very minimal electrical to get final. once the permit is over, then go nuts.

Even the stuff you do after the final is supposed to be inspected. Failing to do so could lead to some fines, and your insurance company dropping you like a alcoholic boyfriend...

 

[alfredeneuman]

As previously stated #3 is only good for 115 amps Table 310.15(b)(16) so that 125 amp breaker is a no go.

That figure is from the 90 degree temperature column, which is used only for derating purposes.
The terminations on the breaker and the panel determine the ampacity which are 75 degrees, thus 100 Amps is the correct figure.

 

[AuroraSC]

If you run conduit you can always pull the wire out and pull in bigger wire if the need should arise. Personally I ran PVC under slab to each and every outlet so I can make any of them into anything I want at any time. It's also incredibly cheap to do PVC under slab so more money for beer and tools!

As previously stated #3 is only good for 115 amps Table 310.15(b)(16) so that 125 amp breaker is a no go.

I don't understand the purpose of the second conduit thing. You could always pull a sub panel off the shop panel if you needed more space. If you're trying to get more ampacity for some future stuff I would strongly encourage you to just do it right the first time and run some larger wire 4/0 4/0 4/0 URD is stupid cheap and can be thrown right into a trench along with a #2 for ground and you have 200 amp rated wire... albeit it's aluminum. Also 200 amp panel on a 100 amp breaker... if your plan is to just run another set of wires and make it a 200 amp service at a latter time... think again. 310.10(H)(1) requires those feeders to be 1/0 or larger before you can parallel them.

Also Cat 6... You probably don't need it Cat5e is plenty good for the average home user, and if you're running it underground I would suggest a flooded core cable, and to put surge suppressors on both ends to prevent equipment damage.

I'm not a fan of HO panels I prefer QO but at least it's square d!

I'm glad that I made the post. I'm an engineer by trade, but of the mechanical variety not the electrical. Electrons and I have had our share of ups and downs over the years.

Wire Sizing - Per the document you referenced, I would need to run #1 wire using the 75° C column for 125A service. If memory serves earlier on he had mentioned using #1/0 wire which seems like it might be slightly overkill based on the chart. The wire has not been purchased yet, so I will clarify.

Additional Conduit Stub - The intent for the additional large conduit was to allow me to add another 125A breaker to the other panel in my garage (I have (2) 225A Eaton CH Panels in the home garage that are each approx half full). This would allow me to run an additional homerun from the garage to the shop for an additional 125A worth of service.

The 125A breaker from the main garage has been conveyed as the easiest and most cost effective solution for powering the shop. If you feel this is an error, please explain. I'll be re-reading your post and trying to discern it more clearly as you may have already tried to do so and I didn't' follow.

Shop Breaker Panel - As far as the shop panel goes, it seemed like a cost effective solution and was on the shelf for purchase at Lowes. If you feel there is a better solution available I'm open to other alternatives.

Cat 6 - It's overkill, but it was $30 dollars more for 1000ft so I went with it.

 

[colomboj]

That figure is from the 90 degree temperature column, which is used only for derating purposes.
The terminations on the breaker and the panel determine the ampacity which are 75 degrees, thus 100 Amps is the correct figure.

Since when has the 90 degree column only been used for derating? That's news to me.

And yeah lugs are all rated at 75 but that's none to do with the conductor size.

 

[colomboj]

Wire Sizing - Per the document you referenced, I would need to run #1 wire using the 75° C column for 125A service. If memory serves earlier on he had mentioned using #1/0 wire which seems like it might be slightly overkill based on the chart. The wire has not been purchased yet, so I will clarify.

Depends on the type of wire you are using. We use THHN and THHW for most of our work unless there is some other specific environmental factor we need to account for. Using that would require a #2, but that said you can always go bigger, but never smaller. Also you are going to run into an issue if you use #1's in an 1 1/4" conduit, conduit fill limits you to 3 #1's (Table C.10) and you have four wires to pull down that pipe. Even with #2 you're going to want to lube that wire good and plenty and prepare for a battle.

Additional Conduit Stub - The intent for the additional large conduit was to allow me to add another 125A breaker to the other panel in my garage (I have (2) 225A Eaton CH Panels in the home garage that are each approx half full). This would allow me to run an additional homerun from the garage to the shop for an additional 125A worth of service.

Do you have GEO thermal heat or something because it's not typical for a house to have two panels like that unless one of them is full, or there is a separate heating panel with a second meter for reduced billing. If that's the case, and you are going to run a second panel for heat in the shop to get that reduced billing it makes all the sense in the world to do it.

Otherwise I have never ran into any case where running two 125amp feeders was a less expensive option than running one 200amp. Twice the equipment, twice the pipe, twice the labor. I look at it from a professional contractor view and see nothing but money spent for no gain.

Maybe you don't even need that second panel... not that I'm one to dissuade someone from having more power, but if you're not running a semi pro machine shop, and just doing the hobby thing you probably don't need that much power anyways. If it's a hobby shop, like most, you are probably not running multiple pieces of machinery at the same time. So maybe that first 125 is all you need.

The 125A breaker from the main garage has been conveyed as the easiest and most cost effective solution for powering the shop. If you feel this is an error, please explain. I'll be re-reading your post and trying to discern it more clearly as you may have already tried to do so and I didn't' follow.

The 125 amp thing is fine, the thing that makes me scratch my brains is that you want to install all of it twice over.

Shop Breaker Panel - As far as the shop panel goes, it seemed like a cost effective solution and was on the shelf for purchase at Lowes. If you feel there is a better solution available I'm open to other alternatives.

Since you have a breaker in the main panel already the most cost effective solution is to use a main lug panel. You would need to go all the way back to the main panel should there be a main fault, of course this is already the case since you have a 200 amp breaker downstream of a 125 amp. The only thing it is useful for is to act as a disconnect, and it's perfectly reasonable to use it for that purpose alone.

 

[colomboj]

Also one last thing there... I noticed you put all your 50amp outlets fairly far away from the panel on the layout there. I would put the panel and the large equipment closer together or maybe add a sub panel by the equipment. That would reduce the amount of wire, and conduit, you need to run to the equipment. Labor and wire are the most expensive parts of the installation so the less of both you use the more money you have for beer and tools!

 

[colomboj]

By Code, you're only allowed a single feed (the panel) to an outbuilding such as a pole barn, so the conduit to be used for future power needs is a no-go

You are only allowed one service, unless you meet some exceptions, but this isn't a service. It is for all intensive purposes a branch circuit feeding a sub panel.

 

[Stuff]

Depends on the type of wire you are using. We use THHN and THHW for most of our work unless there is some other specific environmental factor we need to account for. Using that would require a #2, but that said you can always go bigger, but never smaller.

#2 cu would only be if for a service at 125a. This is for a feeder so needs to be 1
awg.

 

[Stuff]

You are only allowed one service, unless you meet some exceptions, but this isn't a service. It is for all intensive purposes a branch circuit feeding a sub panel.

Feeders to other buildings/structures also have restriction of only one feeder.

*** all codes are local in the end ***

 

[AuroraSC]

Depends on the type of wire you are using. We use THHN and THHW for most of our work unless there is some other specific environmental factor we need to account for. Using that would require a #2, but that said you can always go bigger, but never smaller. Also you are going to run into an issue if you use #1's in an 1 1/4" conduit, conduit fill limits you to 3 #1's (Table C.10) and you have four wires to pull down that pipe. Even with #2 you're going to want to lube that wire good and plenty and prepare for a battle.


Do you have GEO thermal heat or something because it's not typical for a house to have two panels like that unless one of them is full, or there is a separate heating panel with a second meter for reduced billing. If that's the case, and you are going to run a second panel for heat in the shop to get that reduced billing it makes all the sense in the world to do it.

Otherwise I have never ran into any case where running two 125amp feeders was a less expensive option than running one 200amp. Twice the equipment, twice the pipe, twice the labor. I look at it from a professional contractor view and see nothing but money spent for no gain.

Maybe you don't even need that second panel... not that I'm one to dissuade someone from having more power, but if you're not running a semi pro machine shop, and just doing the hobby thing you probably don't need that much power anyways. If it's a hobby shop, like most, you are probably not running multiple pieces of machinery at the same time. So maybe that first 125 is all you need.


The 125 amp thing is fine, the thing that makes me scratch my brains is that you want to install all of it twice over.


Since you have a breaker in the main panel already the most cost effective solution is to use a main lug panel. You would need to go all the way back to the main panel should there be a main fault, of course this is already the case since you have a 200 amp breaker downstream of a 125 amp. The only thing it is useful for is to act as a disconnect, and it's perfectly reasonable to use it for that purpose alone.

I had initially suggested that I wanted to run 200A worth of service to the building. He said it would be more cost effective to just do the largest panel breaker and use that as the feed line (hence the 125A). I'm a fan of overkill, but from talking with him it sounded like it would be hundreds if not a thousand dollars more to go 200A instead of 125A. When running the trench and tubing to the house I asked if it was a good idea to run an extra conduit for future use, and he seemed to think it was a good idea. I then had the thought of just doing (2) of the 125A breaker runs. We didn't discuss the cost impact of it versus just doing the 200A at that point.

The house does have (2) main boxes. I had talked about an interest in a shop and/or geothermal when building the home which drove them to upgrade to two panels.

In a quick look for a lug panel (also called a sub-panel if I'm following correctly) they appear to be the same price or possibly higher for the higher circuit options. If the money is the same it sounds like either a main breaker or main lug could work so I may just stick with the breaker box. I do think I want to add in the sub-panel near the rear of the building to service those welder outlets. This was something I had discussed previously and forgot to add to the drawing.

 

[n20junkie]

1.25 conduit? You really should have put at least 2” conduit in. Pulling anything service cable size through that will ****.