Electric service to barn

[fishpick]

Cliff_Johns - Copper?! I couldn't afford 2/0 copper! no it's al-u-min-e-um!

Sully2 - I know I don't need conduit the length of the run... BUT - it clay and stone... and we freeze deep up here... so sans conduit I would need a sand filled trench to keep the heaving rocks that perennially migrate to the surface from pinching or poking the line. Conduit is cheaper and "easier" than sand... because I'm not pulling through it - I'm sliding it down the cable and gluing in place. Ohh - thanks on the HD tip - I'll look tomorrow!

podagrower - we apparently have 2 options in the code here... option 1 is my way - a 3 wire bundle that's 2 hots and a neutral - then have 2 grounding rods... option 2 is a 4 wire pull (more money) - that would be 2 hots a neutral and a ground... then drive 1 grounding rod out there... For my money 2 grounding rods is a lot cheaper.

 

[Eric_Phillips]

Fishpick- Does that all hold true if you have another metallic connection between the two buildings like a phone line? If you do have the second connection I thought you had to run the ground from the main panel. I could be wrong. By the way are you out east of Rochester?

LBrown59- I am going to use #2 wire out to the barn.

 

[Farwell]

podagrower,
Run the ground wire. I wish I had the 4th wire to my out buildings but the wire was already buried when I bought the place.

 

[fishpick]

Eric_Phillips - Yesss - sir... 315 calling! I dunno about the "other metallic connections part... I'll have to ask around.

Farwell - why? A ground it the ground a world around... what's the benefit of fighting another large wire for the length of the run - and paying more for it...

Of course - Eric_Phillips may have answered that - if the code is other connections will require a ground back to the house - that would explain why they make 3 and 4 wire stuff in the first place!

 

[6sunset6]

You MUST run a separate ground wire in the conduit out to the barn. In addition you must float the neutral buss in the barn panel. This means you do not put in the screw that ties the neutral buss to the pan. You will probably have to buy a separate ground buss bar (not expensive) to tie the ground distribution wires to. In a main panel the ground and neutral are on the same buss.
The reason for this is that the ground system wants be a tree with no loops in, to avoid stray currents. Also the ground system in the barn has to be at the same potential as the ground in the house and going through rods in the earth does not do it, but you still need the rods . 2 six feet apart is also correct.
I think you can use the panel you mentioned but be careful not to overload the distribution breaker in the house panel. If you put a 100 amp main breaker in the barn panel you will never be able to do that.

 

[mudcat]

250-32 NEC.

 

[podagrower]

Fish, one more small point. Most resedential panels have a limit on how much current you can draw from the "fingers" of the bus (where the breaker actually attaches). Most are limited to 140 amps for any two "fingers". This means wherever you install the 100 amp breaker, the breaker(s) on the opposite side should total less than 40 amps. Two 20 amp circuits, no problem, one 60 amp double pole to feed your furnace, possible trouble.

 

[Sully2]

Two 20 amp circuits, no problem, one 60 amp double pole to feed your furnace, possible trouble.

A 60 amp-220V breaker needed for a "furnace"???

 

[DWW68]

Fishpick
You may already know this or it does not pertain to your application, but it is often over looked and a pain in the @$$ to change when the inspector fails you because you do not have them.

If your conduit is comming out of the house and or barn is not below frost or above grade before it goes below the ground, you will need expansion joints installed. These are basicly a slip joint that will allow the conduit to heave with the frost with out creating any damage. If the ground moves, so will the conduit. The house or barn will not move. End resault is the conduit will most likely snap where it enters the house.

Just thought that I would mention it in case you over looked it.
Dan

 

[mudcat]

A 60 amp-220V breaker needed for a "furnace"???

It is a southern thing.

 

[fishpick]

6sunset6 - OK - so let me spit back what I think you are saying... From the main panel in the house - I run 4 wire out to the barn... 2 hot, one neutral, one ground... but in the house since neutral and ground are "the same" - they are basically connecting to the big blocks you use to hook big wires onto the small bars...
Then - out in the barn - the ground will go to the "ground" bar - where there will also be a copper line running in from the 2 ground rods... and all grounding lines for barn circuits run there... then the neutral runs to a "floating" and insulated from the panel neutral bar... where the neutrals run...
Attached to the post is a diagram - is that right?

mudcat - Code Basics confuses me - one sounds like one thing - the other something different... meaning - 3 wire vs 4 wire between house and barn... The first 250-32(b)(2) reference (Grounded neutral conductors serving another building from a main building) sounds like what I'm talking about... but the other one does too...

podagrower - The 100 A breaker is on the main in the house - the sub also has a 100A main - nothing in the sub can draw more than 100A - so it will never draw more than 100A on the main in the house.

DWW68 - overlooked - now - not so much - added to the list of things to do... and it also explains why the existing conduit the previous guy put in is snapped right off at the house!

 

[6sunset6]

You got it .

 

[6sunset6]

Oh yeah the confusing part is grounded conductor the neutral and grounding conductor the bare or green one.
I am not sure but I don't know if you can get 4 wire direct burial . I put my stuff in conduit deep probably 5' when all was said and done. I used triplex which is direct burial but cheaper than anything else and then added a ground . Ay least cheaper for me at the time. If you are using aluminum, and there is nothing wrong with it for mains, you need to use something called NoCORODE I think. It's a paste that you wire brush onto all suraces of the aluminum cable where it goes into the compression connectors. Keeps aluminum oxide from forming. Torque wrench is good to use also. I think there are labels on everything for the correct torque. Boy, it has been a long time since I have done this kind of work. One more post and I will have to head for the code book.

 

[whodat90]

FWIW, before they brought the power out to my barn I was backfeeding the panel through an extension cord from the house. (10ga 75' RV cord) Worked just fine till we put in two ground rods for the barn's panel, then it tripped the GFI the extension cord was plugged intoat the house. The GFI was sensitive enough to note the difference between the house ground and the ground rods for the barn. So yes, a ground is a ground the world round, but the GFI wasn't fooled.

 

[fishpick]

Gonna be doing this in a couple weeks - question - can I also run water in the same trench as electric in NYS - Wayne County?

And I'm guessing it needs to be below the 48" frost line...

SO - is the right way to put the water in the trench to drill a hole in the block foundation and feed the pipe through - then mortar back around the pipe?

 

[LBrown59]

*SO - is the right way to put the water in the trench to drill a hole in the block foundation and feed the pipe through - then mortar back around the pipe?

*Put something on each side of the wall and you will not have to tunnel under the wall if you ever need to repair or replace.
__________________
I just got done doing that very thing a few minutes ago on the garage wall that I had ran electric and phone lines through.

 

[Farwell]

Fishpick,
Putting anything else in the trench with the electric is not recommended and probably violates all of the codes, national and local with the possible exception of communication lines.
My frost line in Mid Michigan is 42 inches and is the recommended depth for water lines but I do not know what the depth for electric conduit, I usually bury my electric at around 24 inches.
This is what I have understood the national code to say, if you run the three wires to your barn it is okay, but the ground and neutral are bonded in the barn box and ground rods are necessary. If this is the way you wire your barn you will want to avoid anything that may be attached to the house grounding system, telephone lines, cable TV lines, water lines, etc.

 

[fishpick]

if you run the three wires to your barn it is okay, but the ground and neutral are bonded in the barn box and ground rods are necessary.

Here's what I'm planning - as per this discussion...

http://www.tractorbynet.com/forums/...1d1180903741-electric-service-barn-wiring.jpg

4 wires - floating neutral in the barn box.

Just trying to figure out of I can get the water out there with the electric too!

 

[Savagepike]

I would highly recommend that if you're powering the barn off of your existing house service, you upgrade to a 320amp service to be safe. You can get this done for free (at least where I live) if you do the following... Go ahead and run cable out to your barn like you would do anyway. Just make sure you're not going to have voltage drop problems with the length/cable size, (buried cable doesn't handle as many amps as open or exposed does). Get everything in your barn wired up and completed. Then call your local electric utility and tell them that due to your barn now having power (key term: welders), your existing service in no longer adequate. This will most likely get you a free service upgrade and depending on your situation, an upgraded transformer to carry the additional current and prevent flicker.

 

[Farwell]

Fishpick,
The way you described your wiring plan is the recommended way.
I do not recommend putting water in the same trench as the electrical and I doubt that anyone else will.