Wiring of Subpanel and HD Instructions

I am wiring an out building with 220/220 and have the 60 Amp breaker to install inside the house breaker box using 6 ga wire leading to the outbldg. The HD electrical aisle rep indicates that I should connect the neutral in the outbldg to the ground. I think I need to connect the ground to the "house ground" leaving neutral alone. In essense, I think I should use 4 wires from the house to the bldg, 2 110v lines to get 220v, a neutral and a ground to the main panel. Am I correct or am I short circuiting myself? Thanks

 

with a 4 wire system the N and the G are seperate in the sub, but you need to add ground rod to the equipment ground bar at the outbuilding.

 

Either answer could be correct, depending on the situation.

The big question is: "do you have any metal connections between the two buildings? (water line, gas line, etc.)

 

No, there are no metal connections/pipes or anything else metalic between the main hour and the outbuilding. I live in the country and have total electric. Hope this answers your question.

 

If you use 4 wire you do not bond, if you are using 3 wire you do, you indicated you were going to use 4 which I think is a good idea even if there are no interconnecting parts, never know when someone buries a water line or phones, then there is no worry.

 

You indicate "bond" and I am not sure exactly what that means. Does that mean join the ground somehow? Thanks

 

The word "Bond" refers to a specific type of connections at the Service equiptments which is solid connections between Grounding elements.

For your Bonding application, you will "Bond" together at the panel the metal of the enclosure, the Grounding Electrode Conductor, the Equiptment Grounding Conductor in the Feeder circuit, and all Branch-Circuit EGC's.

The Grounded Feeder Conductor (Neutral) is isolated from all Grounding/Grounded points.

Good Luck & Enjoy the Experience!!!!!!!!

 

For my bonding experience, I wired the outbuilding today. I have 110/220. I connected the neutral to ground and hope I did right.
Did I do good?

 

If you ran three conductors without a grounding wire and without metal conduit between the buildings, then you did good. If you ran a grounding wire or metal conduit between the buildings, then you did bad.

 

Well...I ran four wires. Two were 110 for the 220 and the other one was neutral and yet another neutral. Total of 4. Does that make sense? I sure hope I did right worked with the wiring all day until I was exhausted. The neutral and grounds in the sub box are connectd but it did confuse me because I was connecting the wires I thought for sure I'd have a short.

 

No actually it doesn't make much sense. Two neutrals?

 

John, there were two bars on either side of the main breaker box. In each of these two bars were neutral and ground. I would have run four wires anyway but someone on this thread told me if I ran 4 wires it was better. If i can get by with 3 wires, so much the better because I pulled it through 3/4" PVC and it should have been at least 1". (rough) I was thinking ground, neutral, 110 and 110 for a total of 4. Should I remove one of the neutrals? Thanks

 

Are both of these neutrals insulated wires? Copper or aluminum? What color? What gauge? Same information please for the hot wires.

 

All wires are insulated. Both of the hot wires are 6 gauge, one of the neutrals is 6 gauge and the other a black 8 gauge. They are copper and the colors are white except for the one black. (because I bought a reel of wire -less cost than if I had HD run each color and cut. Also, I do have the circuit breaker turned off in the main box inside the house. Hope this helps. I'd sure like to pull that black neutral out and just have the 3 6 ga wires.

 

Yes, please pull out that black wire.

 

Thanks! I'll do it first thing in the AM. Should I post back?

 

Far better if the "4th. wire" remained in the Feeder circuit to be connected as an Equitment Grounding Conductor.

Art 250.32 (Detached Structures) (B) (1) reads-----"An Equiptment Grounding Conductor shall be run with the supply (Feeder) conductors-------"

An Equiptment Grounding Coductor can be perceived as a "2nd. Neutral" for conducting a Fault-current "back to the source" which is where the circuit-breaker is connected. The purpose is to "trip" the circuit-breaker ASAP if an Un-grounded Circuit Condutor makes contact with the metal surfaces and frames of connected loads. This requires a conductive path of near-Zero resistance to conduct a large Fault-Current that opens the circuit immediately by "tripping" the C-B.

If the metal surface of a kitchen couter-top appliance such as a toaster was connected to a EGC, the EGC would serve as a "2nd Neutral" for conducting a Fault-current to where the C-B is connected should the Un-grounded Circuit Condutor make contact with the metal surface of the toaster.

A "dead-short" between the Un-grounded Circuit Conductor (Black wire) and a properly connected EGC would be almost similiar to a "dead-short" between the Black & White circuit-conductors.

 

I'm inclined to agree that keeping the fourth wire is the best plan here. But, you'll have to remove the jumper between the ground and neutral bars in the sub paneland terminate all neutrals on one bar (the one that is insulated from the panel enclosure) and all of the grounds on the other bar (the one that is attached or bonded to the panel enclosure.)

If you opt to use three wires, you'll have to drive ground rods for the sub panel.

 

Who knows what panel is there or how its configured. Could be both actual neutral bars in it or one may actually be an equipment ground bar. This is a job that should obviously have an inspection.

 

You are not allowed to use a black wire for the EGC. When you pull out the black wire, you could use it to pull through a bare or green for the EGC. You can use #10 for the EGC, so it will be easier to get through. I agree that this would be an excellent thing to do (but only if you separate the neutral and ground in the out building).

You need ground rods whether or not you have fourth wire (the EGC). One cannot replace the need for the other.

 

Green marking tape is the solution, and #8 is preferable to #10.

Good Luck!!!!!!!!!!!1

 

I have a Challenger Breaker in the garage and Homeline in the outbuilding. I used 6 gauge wire (3). One moderator said 4 is best and another told me to take out the 4th (Blk) which i did this AM. I do not have a ground rod in the outbldg. 2 110v lines are going out from the inside box to the HOM, then, I have bonded the ground and neutral together in the HOM and have been running a compressor and chop saw this AM. I know just because I can run power tools that doesn't necessarily mean I have wired anything right. I am going to install GFI's on the last leg of wiring within the outbldg. What do you think? Do I need to put in that grounding rod? I've been researching various posts on Doityouself and one moderator told someone that the ground in the house is adequate....thanks !

 

Remarking of an EGC that is #6 or smaller would be a code violation. See 2002 NEC article 250.119.

 

pop, can you point us to the thread (threadid number would be good) of the thread you read where it was stated that grounding rods would not be required? I'd like to see in what context that advice was given.

GFCI on each of the outbuilding receptacle circuits is good. In fact, required.

As you said, many things that work are not safe. I agree with sberry that you should have this job inspected by the city inspector for your own protection.

 

John, I don't know the thread number since it's been several months that I've read the post. It's hard to prove something when one cannot back it up by something. I'm sorry. I'll have an electrician inspect the building before I hardboard the walls.
Thanks for the help

 

Papa, despite how it may appear there is really no difference of opinion here among the respondants. 1. if there is no interconnecting metal 3 wire is legal with bonded panel. 4 wire is legal with interconnecting metal parts or without, either way. Its often prefferable in case someone adds something such as a gas line, phone line or metal water line in the future, its covered, its a done deal. When using 4 wire you need to actually add a ground bar kit that screws directly to the panel case, it does not come with a new homeline panel. What you were looking at if both bars insulated from the can were actually 2 neutral bars, they are connected together and are 2 pcs just for convinience of routing wires. When you add bond screw it connects the neutral bar to the panel case, hence the bond. You must do this with 3 wire and not with 4. Because you seemed confused John suggested just yanking the 4th wire which brought this into compliance and you already had it bonded anyway and the wire was colored against the code requirement of not remarking wires smaller than 6 (it was an 8) it was sized right, just the wrong color. Now, either way, 3 wire or 4 you still need at least one ground rod connected by a minimum of number 8 wire, green or bare.

 

Thanks, I'm putting in the PVC lines tomorrow and I plan on a ground rod. I thought of rebar as some builders use but copper will last.

 

Not to confuse the original poster, this is a question directed to another party, with no bearing on your install.

John, if an outbuilding were fed with a sub-panel, four wire feeder, and the building had a continuous metal path of sort, why would you need to drive ground rods? For all intents and purposes it is one building at that point. If I put a sub panel on the second floor of my home, does it also need a ground rod? If so, where do you buy rods that long?

 

The grounding wire between buildings is an Equipment Grounding Conductor (EGC).

Grounding rods and the Grounding Electrode Conductor (GEC) are part of the Grounding Electrode System.

These two grounding systems serve completely different functions. There is no reason at all that one could serve the purpose of the other. The grounding rods are necessary because the space betwen the buildings provides a spot for lightning to strike.

The grounding rods are primarily for lightning protection. The EGC is primarily for personal and fire protection. True that they are connected to the same place in the panel, and they both have the word "Grounding" in their names, but these two things are all they have in common.

 

I sure appreciate the way you kind folks are helping me do this project. I took the black wire out so now I don't have the lightning protection right? Also, am I to understand that the ground inthe outbldg is to be entirely seperate from the neutral?
That is, NO neutrals are to be connected to the ground only ground wiring. Thanks

 

No.

Without an Equipment Grounding Conductor between the buildings, you must connect all of the grounding and neutral wires in the outbuilding to each other and to the neutral wire from the house. Otherwise, your grounding in the outbuilding is completely ineffective. If a ground fault occurs in the outbuilding, you need the fault current to be able to flow through the neutral connection back to the house. Otherwise, the breaker will not trip and somebody may die.

Yes, you need grounding rods for lightning protection (and to comply with code).

 

I understand . ALL the ground wiring and neutrals will be connected in the outbuilding. I'm sure glad I don't have to fish that black wire through again. Thanks John, I think I have all bases covered.