Old electrical wiring to outbuildings

I bought an old farmhouse last year and I'm finally getting around to fixing up some of the out buildings. The two that I'm working on now each have power that comes from the main breaker panel in the house. Each building has it's own fuse box with wiring extending from that. Now on to the problem.
In the main breaker panel there are two seperate 30 Amp breakers that each have a very large wire coming out of them. They aren't connected like a double pole and aren't next to each other like a double pole breaker. The two wires run into a single cable along with another large wire wired to the neutral bus. The label on the cable is "E32071 (UL) 3 CDRS AWG 6 TYPE SE CABLE STYLE U TYPE XHHW CDRS 600V". Now, the cable goes out of the house and through the air to the first building (Building A). Outside Building A there are severla wired wired and taped together. One of the hot wires runs into bulding A and the other wire splits into building A and also heads off to the other building (Building B). Inside building A there is a fuse box and the hot and neutral wires run to the normal connections. The other hot wire and the split from the netural run through the air to building B where the neutral and other hot wire run into a fuse box and throughout the building.
Now for the question. I would like to replace the wires in the air from A to B and replace the fuse boxes with a circuit panel. What I'm considering is running both hots and the neutral into a 6 circuit panel inside Building A and then running 1 circuit in A and 3 circuits over to B through some underground conduit. The other issue that I see is that currently at the splice outside building A the heavy wire is spliced to some smaller old wire, it looks like around 10 gauge, that runs from the outside into the building. I'm guessing that if I splice the heavy wire coming from the house to a line into Building A I need to keep it the same guage, right?
Sorry for the long explanation, but I wanted to try and explain the situation better. If a picture would help, I can sketch one quick and post it to my website. Any thoughts that you have would be great.
Thanks, Nate Baxley
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Nate Baxley wrote:

Step one is to normalize the arrangement of the supply. Best practice would be for the two thirty ampere breakers to be replaced with a double pole breaker. In some panels the two breakers could be a double unit and yet appear to be separate. Rearranging breakers in a panel must be carefully done in order to avoid causing problems elsewhere while trying to solve the problem on which you are focused.

I'm going to guess that the installation will be done in an area were the US National Electric Code is the standard for installations. You cannot run multiple branch circuits from one building to another. Each building must be supplied by a single branch circuit or feeder unless the second circuit has totally different voltage characteristics or it is an emergency circuit etc.
I'm guessing that you plan to run the new circuit underground. One way to do this would be to place a splice box at the end of the first underground raceway. You then run the feeder inside to the building disconnecting means from the splices. The other leg of the feeder would be run to the next building's disconnecting means and it would supply a second feeder supplied breaker panel.
The other possibility would be to route the feeder to the building that needs the three circuits. You could then run the single circuit to the other building. -- Tom H

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Several people have gotten a laugh out of my wiring job. I have a new breaker panel in my barn, with all new wiring. The problem is that I have a shed about 50 feet away, and I wanted a light in there, since I mix my horse feed in there, and often feed after dark in winter. The shed is below a hill, about ten feet higher than the barn, and the hill starts right next to the barn, goes upward, and back down to the shed..
I placed several T-posts up the hill, and used the porcelain insulators used for electric fences to clamp some 12-2 UF cable to these T-posts. This wire comes off the edge of that barn roof, and shoots right up the hill, so the wire is actually about 12 feet overhead at the barn, and the same at the shed end, because the hill is in between them.
I'm sure it's not legal according to the code, but I'm not too worried about it. All it's for is a light, and I put an outlet in there too, mostly just in case I need to use a power tool in there.
wrote:

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Thanks Tom, OK, I want to make sure I understand what you're telling me. My explanation of running the main feed from the house to Building A isn't a problem, it's the part about running the 3 circuits from A to B, right? The problem is that A is physically between the house and B. So I'd have to run under or through A to a circuit breaker in B and then run a single circuit back, probably through the same conduit, to A. Would that work? Does that make sense?
On your other comment about grounding, are you saying that I need to have a ground wire that runs back to the main circuit breaker in the house? What about installing a grounding rod a the new circuit breaker? Would that aleviate the "stray currents" problem?
Thanks for your very informative post. I look forward to your reply. Nate

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Nate Baxley wrote:

You can run under A but not through it. You then run a single branch circuit to building A. You might want to consider running a separate branch circuit to building A from the main panel in the house and run the feeder to building B. You can run those in the same conduit as long as the feeder conductors do not enter building A. Having both circuits run through the same pull box on the outside of building A is OK.
Read my reply to someone else on the grounding issue. Grounding will be required at the building that has a panel in it. You run a four wire feeder, terminate the neutral to an insulated neutral buss bar in the panel, terminate the Equipment Grounding (bonding) Conductor (EGC) to the bonded buss bar in the building B panel, install a grounding electrode system at building B, connect the Grounding Electrode Conductor (GEC) to the bonded buss bar in the building B panel.
If there are no metallic pathways between the two buildings you are not required to run an EGC with the feeder. You are required to have a grounding electrode system at each building that has more than a single branch circuit run to it.
If you do not run an EGC with the feeder than you must bond the neutral buss bar to the building B building disconnecting means enclosure, i.e. to the building B panel cabinet.
The building B panel must be marked as suitable for use as service equipment. If the building B panel will contain more than six breakers either now or in the future you must provide a building disconnecting means in the form of a main breaker or in a disconnect ahead of the building B panel that is located on or in building B.
The stray current problem is caused by running a three wire feeder rather than a four wire feeder with a separate EGC. Since you have to bond the grounded current carrying conductor to ground at each building if you do not run a separate EGC with the feeder the neutral currents will be divided between the neutral conductor and the earth. This can cause a step potential across the surface of the earth between the two buildings to which some livestock are extremely sensitive.
Once again the best practice is a four wire feeder even though the code allows a three wire feeder in the absence of other conductive pathways between the buildings.
No matter which feeder you run you must build a grounding electrode system at each building that is supplied by more than one branch circuit. -- Tom H
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wrote:

I have livestock, and never understood this. What do you mean by "step potential"?
I have a main pull out fuse box on my transformer pole, and from there, it feeds to each large building, using overhead triplex. Each of these large buildings has their own breaker box, with their owm main disconnect. Each has their own grounding system and each has the bond screw installed. The only buildings that do not have their own breaker box are small sheds, and those only have a 110 line feed from the barn, and are just for a few lights. So, I think I am safe. However, I want to better understand this "step potential".
PS. I learned a nasty lesson the other day. I have electric fences. I was filling the livestock water tank, and decided to take a drink from the hose. I put the hose up to my lips, and the water stream touched the fence. DAMN THAT STUNG !!!! It's one thing to touch an electric fence, and I do it often, but getting it in the mouth was nasty. I never thought it would travel thru water (except salt water). Guess I was wrong.
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snipped-for-privacy@nospam.com wrote:

Step potential is the difference in voltage on the surface of the earth across the length of the subjects stride or step. In livestock it is possible to have a stand potential since they have their feet a yard or more apart when standing. If any of the neutral current flows through the earth instead of through the neutral of your triplex, and on ground laden with animal waste it will, there is a voltage drop between the animals front and back feet that can cause a measurable flow of current through the animal. Some stock are more sensitive to this than others. Losses of thirty percent or more of production have been reported in dairy herds. Any Qualified electrician can check for this by checking for current flow on each Grounding Electrode Conductor (GEC) and voltage drop between the various grounding electrode systems. The cure for any problem on your farm may be as simple as running quadplex from the yard pole to each building and isolating the neutral in each buildings panel by removing the bonding screw and installing a separate Equipment Grounding Conductor (EGC) buss bar in each panels enclosure to terminate all EGCs and the GEC for that building. By doing that the neutral will only be bonded to earth ground at the yard pole service equipment. With the neutral bonded to earth ground only at one point you eliminate any current flow between the grounding electrodes at each building as long as there are no ground faults on the farms electrical system. That will eliminate step potential as long as there is no problem with the power companies multi grounded neutral (MGN) causing utility neutral current flow through the farm. -- Tom H
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Nate Baxley wrote:

If the US NEC applies you will need to install a grounding electrode system at each building. Best practice would be to use four wire feeders with separate Equipment Grounding (bonding) Conductors and Grounded Current Carrying Conductor (neutral). By doing so you will avoid the very real possibility that there will be stray currents running around the property. Such currents can cause discomfort and ill health in live stock and the risk of electric shock to both animals and humans. -- Tom H
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Tom you mentioned grounding electrode system and a 4 wire feed. Could you clearify that a bit? Did you mean that you should bring the ground with the feeders to each building ? When you said grounding electrode I hope you didn't mean ground rods for each building ? There should only be a grouding electrode at the main panel then a 4 wire feed to the sub panel with the ground and neutral terminating on thier own busses (neutral bus being isolated from ground) Do you agree or amI missing something? Bill
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... ... wrote:

I'm afraid your missing something.
I'm not suggesting that he should use a grounding electrode system as a substitute for an Equipment Grounding Conductor. I'm not even suggesting a three wire feeder with the neutral bonded to ground at each building disconnecting means, though in the absence of other metallic pathways between the buildings that is a permissible practice. What I am suggesting is the use of a four wire feeder that includes an Equipment Grounding (bonding) Conductor (EGC) with that EGC bonded to a Grounding Electrode System at each building disconnecting means. You are correct in pointing out that the best practice is to maintain the Grounded Current Carrying Conductor aloof from Ground at any place other than the service disconnecting means. Be aware, however that the US NEC specifically permits you to wire each separate building as if it were a separate service providing there are no other metallic pathways between the buildings.
The US NEC requires a Grounding Electrode System at each building unless that building is served only by a single branch circuit. So in the OPs case his building A would not need a Grounding Electrode System as he only needs one branch circuit in there. Trouble is he plans to run the feeder there first. If he can run the feeder to the building that he is calling building B then he can run the single branch circuit that he needs in building A from either the house or building B and he would not be required to build a grounding electrode system at building A. If he does run the feeder to building A then he will not need a Grounding Electrode System there because it will be served only by a single branch circuit. The applicable section of the US NEC is copied below.
250.32 Two or More Buildings or Structures Supplied from a Common Service. (A) Grounding Electrode. Where two or more buildings or structures are supplied from a common ac service by a feeder(s) or branch circuit(s), the grounding electrode(s) required in Part III of this article at each building or structure shall be connected in the manner specified in 250.32(B) or (C). Where there are no existing grounding electrodes, the grounding electrode(s) required in Part III of this article shall be installed. Exception: A grounding electrode at separate buildings or structures shall not be required where only one branch circuit supplies the building or structure and the branch circuit includes an equipment grounding conductor for grounding the conductive noncurrent-carrying parts of all equipment. (copyright 2002 the National Fire Protection Association)
It is worth noticing that this section stands alone and is not modified by other sections. Any building that contains over current protective devices has to have a grounding electrode system.
I hope that clears up any confusion. -- Tom H
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Nate Baxley wrote:

I've been reading all this, and I almost understand it. I would put a 4-space breaker box in "A" and use a 30A 2-pole breaker to supply the feeder to building B. I would be tempted to reuse one of your fuseboxes for the service panel in "A" and use two 30A fuses to feed "B". Put a shiny new 6-space breaker panel in "B" for its 3 circuits and a little room for expansion. Both "A" and "B" need ground electrodes. Back at the house, replace the two 30A 1-pole breakers with a 40A or 50A 2-pole breaker. Be careful when you move breakers around to keep everything on its original leg or "phase".
I would probably reuse the existing aerial wire from the house to "A", and bury 4 new wires from "A" to "B". It would be better to run 4-conductor cable from the house to "A", but 3-conductor is allowed and I'm a cheapskate. (Did I mention I would try to reuse one of the fuse boxes?)
Have you though about putting a pole at the corner of "A" and using it as a distribution point to "A" and "B"?
Farm wiring is a lot of fun. Just keep in mind that cattle are *very* sensitive to voltage gradients and leakage currents. Pay a lot of attention to grounding.
Bob
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Bob, Thanks for the reply. So if I hear you correctly, I need to put a circuit panel in A, and use a double pole breaker there to send another feeder into another circuit panel in B. I can just use a grounding wire into the ground for each panel, but I still need to run a 4 wire feeder cable from A to B. That sound correct? As for moving the breakers around and upping them to 40 Amps on the main breaker in the house, is that really neccesary? Not to question, but what makes it necesary to move them together and up the ampage? The main reason I ask is that the breaker box is a mess (obviously been added to by some people in a hurry) and I'm dreading haveing to unplug breakers and reroute wires around that box. If it's something that needs to be done, I'll do it but I was just curious as to the reasons.
We currently don't have any cattle, but I'll bone up on my grounding skills before I get into this too much.
Thanks again, Nate Baxley
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OK Nate - you've got your answers, reasons, reasonings, code quotes, etc. Now shutup and get off the internet and do the damn work.
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Nate Baxley wrote:

There are quite a few correct ways to do it; some better than others.
"A" and "B" should each have only one feeder circuit coming in. It doesn't matter whether B's panel is fed from A or from the house. Feeding B off of A's panel sounds simplest to me, although someone else mentioned a tap in an underground juncion box that sounded interesting... but I'd hate to have to dig it up again later and try to find the box if it needed service.
Every building should have a ground.
If you run 4 wires from the house to A, you have to run 4 wires from A to B. If you run 3 wires from the house to A I think you *could* run just 3 wires from A to B, but I wouldn't recommend it.

I depends on how right you want to do it. The mess you have now will work, but it doesn't provide a common trip (if one side overloads and trip it opens the other breaker too, and if you manually turn off one breaker the other is also turned off.) And there's no need to up the breaker size, but you can if you want -- the existing wires can handle it. I mentioned a 40A breaker because I thought you would be buying a new 2-pole breaker anyway to get the feeder circuit into one switch with a common trip.
If you reuse the existing wires, (overhead wires, right? I don't remember) you can start at the outbuildings and get them working first. You can redo the house breaker box later when you get around to it -- which can be postponed indefinitely.
If the breaker box in the house was made by Federal Pacific or Zinsco, I wouldn't open it up either until I was ready to replace it completely (which would be pretty high on my todo list)

Best regards, Bob <-- not an electrician
P.S. I just had another idea. You can run 3 insulated wires in a metal conduit from the panel in A to the point where the wires connect from the house. If you ever decide you want 4 wires from the house instead of 3, you can replace the old triplex cable with quadraplex; connect the bare messenger wire to the metal conduit with an appropriate clamp or grounding bushing, and you won't have to pull another wire into the panel. (you will have to seperate the ground from the neutral inside the panel.)
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