Electrical - Is this legal to code?

[fred.flintstone]

Electrical - Is this legal to code?

I dug a trench from the garage to a toolshed, and put about 30 feet of

12-2 UF cable underground to the shed. Before filling the trench, I decided that maybe it would be best to put two of these cables in so I have two circuits in there, mainly because it gets so hot in there that I might put in a small air conditioner.

The first cable I installed was some UF cable that I got at an auction. It's unused cable, but apparently old stock. The reason is that it does not have a ground wire. The second cable is brand new, because I did not have enough of that old stuff to go twice. I did not realize there was no ground in that cable until I filled the trench, or I would have just bought all new cable.

Anyhow, I ran one cable to the left+rear of the shed, the other to the right+front. After I get it all stapled and into boxes is when I realized there is no ground on that one cable. Oddly enough they both look the same. They are gray and 12-2 UF. I did not know they even made gray without ground. I recall some old white UF that came without a ground years ago.

Anyhow, this is what I plan to do. Both cables are on a separate breaker at the source (garage). In the shed, I will ground the ground wire to the box from the cable that has a ground. On the second cable without the ground, I'll run a bare or green wire to the other circuit that has the ground wire. This will just be a bare copper wire (or green insulated) across the rafters to a box on the other circuit.

Electrically speaking, this is a completed ground, but I'm wondering if an inspector would allow such a connection?

My other option, seems to be to run both cables into one box, near where they enter the shed. That way, there is one ground wire to that box no matter what. Then run my outlets and lights all to that box, but use the hot and neutral wires as planned to have two circuits. This might make more sense but will need more materials to do.

By the way, this will not be inspected. This is rural property and they dont bother with small things like this. I'm only asking both for resale value (at which time there could be an inspection), and just to know how this would be viewed.

[John Grabowski]

*In your particular case I would go with your second option, bringing both cables into one junction box and using the one ground wire for all circuits.

It would have been better and probably cheaper to use PVC conduit and you could pull additional wires in the future if needed.

[RBM]

I agree with John Grabowski, option two. You shouldn't have used the non grounded cable, but option two effectively grounds the system

[Jack Legg]

Time to get your shovel back out and plant some 1-1/2" pvc.

[HeyBub]

Is an actual ground in the vicinity of the un-grounded outlet out of the question?

[trader4]

Yes, that would be a code violation. And I'd go with option #2 as suggested by John and RBM. It's not strictly code compliant, but it's close enough and safe so that I could sleep at nights. Running an exposed ground wire between boxes is just going to raise flags if it gets inspected, eg if he sells it some day.

[dpb]

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The answer to the question asked is 'No', it's not Code-compliant to share the ground between two circuits. In fact, I'm not sure if you're running a 240V circuit it's legal to run just 3-wire instead of 4 any longer altho I guess by your second option you only have two 120V circuits.

It's electrically grounded, yes, and in your situation probably not worth fooling with but if is inspected at some point it will likely be noted as a deficiency at that point. Whether that's a big problem them will depend on circumstances at that time, of course.

Had to put a 4-wire cable down the well last week after had to pull pump owing to in having dropped 'cuz a coupling had been cross-threaded time before and pipe broke. Fishing ruined the wire unavoidably so had to be replaced. Now for some absolutely incoherent reason they say a 4-wire cable is mandated by Code. So there's a fourth wire there w/ nothing to attach to and no purpose if if there were--it's a 240V load w/ no neutral current and an existing ground. The fourth wire is fully redundant. I suggested simply running another 3-wire and just going on but they apparently aren't even stocking it any longer and wasn't worth another trip going to town for for the difference for what would cost from outside supplier.

Just as an aside the small outbuildings here still have only 2-wire service. The barn and elevator are 3 because they do have some sizable loads, but never bothered (and never will) go to the trouble to add the third wire. It's been since REA arrived in '48 and hasn't been a problem yet; I don't see that it's going to be a problem tomorrow... :)

There's no question of selling until I'm out of the picture anyway, so what happens then won't be my worry...we're also outside of direct jurisdiction and out here folks buying farm property tend to not be too worried over the trivia of inspections as are the in-town house-buyers. If the well is good pretty much anything else is fixable.

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[DerbyDad03]

I know I'll be corrected if I'm wrong, but I'm going to throw this out anyway. In fact I'll word everything as a question, so I won't actually be wrong, just curious. ;-)

I believe that code requires a disconnect for out builidings that can be reached from the door. Since you are planning to have 2 separate circuits, do you need 2 disconnect switches? Are 2 disconnects allowed or should you have used 1 run to a disconnect panel and then splilt the circuits inside the shed? (A bit late for that, I would think)

Since one circuit comes into the shed at the left-rear, wouldn't you need to run a wire towards the front for the disconnect?

If so, how will that impact the running of your ground for the ungrounded circuit?

[gregz]

I had a heck of a time pushing 3 10 gauge runs and a data line through my pipe. It's good to oversize. Lubricant a necessity.

Greg

[gfretwell]

If these are "service conductors", you need a warning ribbon a foot above the conductors. (300.5(D)(3).

[dpb]

They're not.

By definition of service and service conductors in the NEC, service conductors must originate from an electrical utility source and end at the disconnecting means.

These are simply branch conductors; that they happen to be underground is immaterial to that.

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[dpb]

On 8/3/2012 9:06 AM, DerbyDad03 wrote: ...

Yes, Code does say there does need to be a disconnect for each branch circuit at the nearest point where it enters the building rather than by the door, necessarily. Since there are more than one of those points (apparently) in this installation, Code says there's to be a plaquard at each location denoting all the other(s).

It does allow for residential outbuildings to use a a snap switch (or a set of 3-way or 4-way snap switches) as the disconnecting means for garages and outbuildings on residential property without having a ?service equipment? rating.

So, his cheapest out that is at least reasonably close would be to wire his inlet into a double box and feed the receptacle from the switch and then if he is going to have another outlet feed it from that outlet.

It all goes to show one ought to do the planning _before_ the construction... :)

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[fred.flintstone]

So you're saying that by code that I need a switch or breaker in the shed that I ran the wires to?

Each circuit has a 20A breaker in the garage. Isn't that enough?

It would be senseless to put another 20A breaker for each circuit in the shed. After all, since both are 20A (in shed and in garage), which one would trip if there was a short or overload?

The thought does occur to put a double 20A breaker in the garage, thus supplying 240V to the shed (240 is not needed), and then put another 20A breaker on each 120V line in the shed. But once again, we're back to the same issue. Both buildings have a 20A breaker, so which one will trip? Since the wire is 12 gauge, I cant put a larger breaker in the garage (such as a 25 or 30A)......

I suppose I could put in one of those old double fuse boxes with a pull down lever to disconnect, and put in 30A fuses, since the wires are actually protected by the 20A breakers.

Yet, all of this seems senseless. If a breaker trips, I have to walk about 35 feet to the garage. I know a guy who lives in a 60 foot long trailer home, and his breaker panel is in the back bedroom. If he's on the other end of the trailer, he has to walk nearly 60 feet to go to the breaker panel. That's almost twice as far as walking to my garage.

The idea of using plain light switches on each of the 2 circuits is simple enough to wire, but they would need to be some heavy duty switches. Plain light switches are not designed for heavy loads. This is a tool shed, there are power saws and other larger motors that need to start up. If I put in an air cond. or use an electric space heater in winter both of those are heavy loads. Those switches would need to be able to handle that current along with the heavy starting current when a motor starts up.

[RBM]

You asked what's legal. The NEC allows you to run a single cable, one or two circuit to the out building without having to install a grounding electrode system. OK, so you've sort of Rubed two circuits

Disconnects aren't necessarily for overload protection. Sometimes they're just required as a safety device

For two 20 amp circuits you can use "Plain light switches" as disconnects. You just get ones rated for 20 amp.

[dpb]

What he said... :)

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No, I don't believe that's kosher. I'd have to look it up to find section but don't think that's approved.

But again it's a _local_ disconnect requirement not for overload protection. That some other application has a longer walk doesn't change the Code reqm't on your situation...

Again, the issue isn't actual electrical safety in this point as it is that you asked about what Code says and what would happen if it were inspected some point in the future.

You might as well while doing something do it near what would meet Code at least w/o major modifications if that's something that is likely.

They need to be 20A on a 20A circuit...that's readily available.

The limiting factor on switch ratings is load switching and these aren't intended to be used for switching the loads; they're there simply as a (inexpensive alternative to more expensive) local disconnect. In an area w/ a shop they could also serve a small safety factor if are any grandchildren, etc., of being able to cut the power tool power at a single location might be a benefit...

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[bud--]

Yes, that is the requirement (225.31)

I didn't remember that other than for services but it is 225.37. I would try to put both UF runs into a single box with a double pole switch or 2 single pole switches. Along with a 2 pole feed breaker, that hides that there are 2 separate branch circuits and that one ground is missing.

You can only run a single circuit, which can be an Edison circuit (otherwise use a feeder) (225.30). In addition to the ground, that is another problem with the plan. As RBM so eloquently said "you've sort of Rubed two circuits".

'Ordinary' wall switches are designed to be used at their rated current. They can be used at 80% of their rating to switch motors (404.14-A-3). A

20A switch is good enough. It can switch a motor rated 16A. I might use a spec grade switch. (That is for a switch rated AC only, which is probably all you can find anyway. An AC/DC rated switch is a little different.)

Receptacles need to be GFCI protected.

[dpb]

On 8/4/2012 11:52 AM, bud-- wrote: ...

Which is true, but the point here isn't that they're going to be switching loads anyways...there are switches on the tools for that.

That's the one I tend to choose to ignore... :)

[dpb]

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He has 5 wires, total...one 12/2 w/G another 12/2 w/o

Rather than all that which isn't compliant either (not supposed to have multiple cables making up one circuit) he might as well just use the one

3-wire from a double-pole supply breaker and go to a box in the outbuilding and then from there the internal circuits. He can have both that way (assuming he uses an appropriate box, of course). He'll still be limited to the overall capacity of the 12 AWG wire but sounds like pretty small loads any way.

What he loses is that at the moment he does have two 20A circuits.

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[krw]

Why?

[RBM]

Because the failure rate is too high. I see no point to having things like sump pumps protected by GF devices. IMO a properly grounded, dedicated single receptacle should suffice, but the Nec no longer has any exceptions for GF locations