Pole barn advice - siding done, power in

[Blue85]

Seems like it takes me forever to finish anything...

I have windows put in - had to cut and re-frame of course. Just 2 in the back wall so both sides can eventually be lean-to's, but I still get a bit of natural light and ventillation. Soffits and fascia done on both sides and siding done on 1 side, but started on the 3 others. Need more ladder...

Everything I read says the old carport was built wrong. Direct buried posts with no bases and not below the frost line. What I'm thinking for the lean-to is get a gas-borer to dig 18" diameter holes about 4' down and use the carboard tubes to pour footings for my posts, using brackets (6x6 posts are above ground). If rock prevents me from boring that deep, then so be it. Attach to rock as possible and send it. Then attach 2 rows of horizontal 2x6 lumber along the side of the building for future bracket/joist attachment (top and bottom of joist) and install siding around those. The carport roof pitch was steeper than the new building, so the plan is to angle the joists up via longer brackets at the bottom.

This also lets me get the building 100% sided before snow comes whether the lean-to is built or not. Power is probably higher priority than the lean-to extension. Everything is pretty much inside right now anyway.

 

[82355]

I wonder how deep I would have to dig to hit rock?'

Martin

 

[ktmoutfront]

In Colorado, I went down 5 feet. 38 holes for 2 barns. Found one 8" rock. Had to pour 12" thick footings in the bottom.

 

[82355]

My neighbor is mining clay out of the dry corner of his field. He is down 50' - 60' or more.

Pictures of the car port?

Martin

 

[Blue85]

The car port is gone and new building in it's place. I'm repurposing those materials to build the lean-to.

 

[82355]

Ah, that makes more sense. I thought you were adding lean tos (lean twos?), to an already improperly built car port. I might have to go back and re read the thread.

Martin

 

[Blue85]

 

[Blue85]

This sticker represents a lot of effort, but now I have power!

Digging the trench was something like 12 hours of ditch witch, shovels, chisels and sledges to go 65'. Some of the rocks had to be split up and torn out. This resulted in a 2-pass approach with the trencher, which just kept sinking. The key was to line the work area with 2x12s. It was all like 30 second passes, then clearing rocks by hand.





I went with a 90A breaker because the ratings are mixed on whether or not you can run 100A service through 2AWG AL. I pulled the bar out of this panel so that ground and neutral are only tied together in the house panel (sadly it makes the wiring more of a hassle having to hit both sides). Sank 2 ground rods outside. I've got a couple of outlets in and will just string some lights in the rafters for now.

 

[CyberSniper]

What made you keep the GE panel instead of going with a SquareD QO?

Just remember you can't have a subpanel on a subpanel when doing your bonding. It's a PITA and largely written because most electricians today don't know how electricity works.

Why do you have two neutrals? When you put that fourth conductor in the conduit you technically have to derate anyway and IIRC it's 80%. So if you had 90C conductors of 2awg that were rated at 100 amps you are now at 80amps. If you have 75C conductors it'd be 80% of 90a which is 70a.

Allowable Ampacities of Insulated Aluminum or CopperClad Aluminum Conductors On American Wire Group

Browse Allowable Ampacities of Insulated Aluminum or CopperClad Aluminum Conductors in the American Wire Group catalog including

wire.buyawg.com

 

[Blue85]

What made you keep the GE panel instead of going with a SquareD QO?

Just remember you can't have a subpanel on a subpanel when doing your bonding. It's a PITA and largely written because most electricians today don't know how electricity works.

Why do you have two neutrals? When you put that fourth conductor in the conduit you technically have to derate anyway and IIRC it's 80%. So if you had 90C conductors of 2awg that were rated at 100 amps you are now at 80amps. If you have 75C conductors it'd be 80% of 90a which is 70a.

Allowable Ampacities of Insulated Aluminum or CopperClad Aluminum Conductors On American Wire Group

Browse Allowable Ampacities of Insulated Aluminum or CopperClad Aluminum Conductors in the American Wire Group catalog including

wire.buyawg.com

I'm confused on a lot here. First of all, there is only one neutral. How do you count two? This is a subpanel off the main panel, so you can't tie N and G together here. If you're de-rating based on # of conductors you only count the current carrying ones (as stated in the link you posted.) Current on the ground is theoretically 0, so the 4th conductor has no impact. Neutral only flows the difference between loads on the two legs, so the sum on all 3 can't exceed 180A. The wire is rated for 100A.

 

[CyberSniper]

I see five wires? The bare ground doesn't count as a conductor.

 

[Blue85]

I knew I shouldn't have posted pictures for internet naysayers...

The bare conductor is obviously to the ground rods. The striped one is 4AWG - ground to the house. The fat ones are obviously L-L-N. This is all required.

 

[CyberSniper]

How does the bare ground leave the conduit if it isn't going all the way back to the house?

They may blow a gasket when inspecting it. The people here would expect you to run your earth ground separately.

They may make you move the ground bar to the panel where the pre-threaded screw holes are there to the left.

Electrically, what you did is fine. The 2010+ NEC is made for parts changers that think the reason why you can't kink wires is because the electrons will flow erratically.

 

[76zimmer]

Inspector in my area required the ground to be run to the main panel in the house, and not have an additional ground wire to ground rod. I thought that strange, but he said its so the ground only has one source that goes directly to the panel where power is coming from.

 

[Blue85]

100' of ground wire won't handle a lightning strike due to the inductance. If your outbuilding panel is close enough to the house ground rods, those suffice (IIRC, @76zimmer has the barn only paces from the house).

Obviously, you can't touch a grounded chassis in both places at the same time, but during nearby lightning strikes you could have a potential difference from your floor/dirt to the potential of all grounded boxes and tools in the building (due to the voltage gradient in the earth).

 

[76zimmer]

I dont think its code, but maybe you’ll be good w that.

 

[CyberSniper]

In the olden days when people bonded their neutral to ground everywhere you'd have ground rods everywhere.

Then one day someone decided to prevent bad grounds from causing floating neutrals, it was common to drag your ground all the way back to the main panel. This is so you didn't have weird floating neutral and ground where you'd see 4-5v of transients. Solve the problem, and greatly reduced the chance of a human getting poked and made it so ground fault interrupters weren't so flaky.

Lightning doesn't give a shit about the conductor. It'll find the path to the earth on a 14awg wire and plasma itself the whole way. The idea of putting your ground to earth in the same conduit as your power wires, with the plan of protecting property and humans, is flawed. The lightning rides outside of the conductor, and the 600v of insulation rating is nothing. This is all because the average electrician today is nothing but a parts changer that follows rules.

Personally, I drag 4 insulated conductors with the intended ground being one smaller between the main panel and any subpanel if it is in conduit. I then put a whole separate ground plane that is bonded on the same ground bar in the subpanel using bare wire rated for the whole panel. Many inspectors will disagree with the separate ground plane because that is what they are told by the big book of stupid prevention.

Around here, and the two counties near me, the inspector will fail you if you put a wire in a conduit between a main panel and a subpanel that leaves the conduit.

 

[Blue85]

Lightning doesn't give a shit about the conductor.

Nonsense. Lightning is a high frequency transient. Surely you understand inductance and resistance. Yes, some current will flow over 100' of 14AWG, but that's not the point of the GES. The bulk of the current goes down the path of least impedance.

The idea of putting your ground to earth in the same conduit as your power wires, with the plan of protecting property and humans, is flawed.
Around here, and the two counties near me, the inspector will fail you if you put a wire in a conduit between a main panel and a subpanel that leaves the conduit.

Back up the assumption train. The bare wire is not routed with the 4 main conductors. They go separate paths just outside of the sub-panel.

250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s).

(A) Grounding Electrode. Building(s) or structure(s) supplied by feeder(s) or branch circuit(s) shall have a grounding electrode or grounding electrode system installed in accordance with Part III of Article 250. The grounding electrode conductor(s) shall be connected in accordance with 250.32(B) or (C). Where there is no existing grounding electrode, the grounding electrode(s) required in 250.50 shall be installed. Exception: A grounding electrode shall not be required where only a single branch circuit, including a multiwire branch circuit, supplies the building or structure and the branch circuit includes an equipment grounding conductor for grounding the normally non–current-carrying metal parts of equipment.

(B) Grounded Systems.

(2.1) Supplied by a Feeder or Branch Circuit. An equipment grounding conductor, as described in 250.118, shall be run with the supply conductors and be connected to the building or structure disconnecting means and to the grounding electrode(s). The equipment grounding conductor shall be used for grounding or bonding of equipment, structures, or frames required to be grounded or bonded. The equipment grounding conductor shall be sized in accordance with 250.122.​

Obviously, the load center in the outbuilding makes the line in question a feeder. If this line went directly to outlets, it would be a branch circuit and no additional ground required (per Article (D)).

 

[Fastereddie]

I’m just following along to absorb info.
I just figured lightning is like the honey badger. It’s gonna go where it wants lol!

 

[CyberSniper]

Nonsense. Lightning is a high frequency transient. Surely you understand inductance and resistance. Yes, some current will flow over 100' of 14AWG, but that's not the point of the GES. The bulk of the current goes down the path of least impedance.

Well, technically lightning is a high frequency dc pulse that looks more like a square wave (rapid rise). Like KHz to 10MHz. So skin effect matters and that is why when you see lightning rods with their wires it's usually stranded of 14awg strands around a core that is essentially hollow. It's also why most wire after 4/0 starts becoming "hollow". Skin effect depth where the weight of the copper versus the current carrying of that copper is about 3/8" at 60hz. Lightning takes the path of least everything and basically once it starts down a path it keeps going and will burn out a conductor and leave carbon trails everywhere.

If you want to see bigly wires I have a bunch in my office.

Back up the assumption train. The bare wire is not routed with the 4 main conductors. They go separate paths just outside of the sub-panel.

What I'm saying is that most localities are expecting nothing entering or leaving a conduit on a feeder between its source and destination. You have the bare wire in the conduit at least part of the way, no? Now by NEC you can even have feeder and branch in the same conduit, and if it's a metallic conduit then they can share the conduit as the ground. So to me, I see no reason why you would put the ground inside the conduit at all if you're just going to break it out a few feet away to find your grounding rods. Because now the inspector is going to wonder what the heck is going on.