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-   -   NEC uses building size?????? (http://www.diychatroom.com/f18/nec-uses-building-size-24535/)

hhiibel 07-31-2008 01:48 PM

NEC uses building size??????
 
My county uses the NEC. I don't know it because I'm not a professional. I've tapped an unused 240V/50amp breaker in my house and done a long run to a stable I'm constructing. Inspector visited before construction, saw the wire in the ground and said OK.

Inspector came out a few days ago. He said: due to the size of my building it doesn't pass because at least 60 amps is required for a building that size. Right now, all I have is a contractor panel on a pole in the ground. I haven't started the wiring in the stable. I planned on needing 120V/60amps. I haven't spoken to the inspector. I wasn't there. The panel is 240V. I don't know what amperage/volt he measured. The three phase wiring is visible at the pole. I calculated I'd see about 240V/30amps due to drop(actually calc said 36amps). I haven't measured.

Here's my question: Does the NEC put forth Amp requirements based on building size? If so, does this take building use into consideration? If so, what use/classification is my building?

My building is a single story, 96'x42' stable. 12 stalls. 2 rooms(tack/feed). Cement floor aisle way and rooms. Dirt floors in stalls. No hot water. No bathroom. Like I said 120V/60amps would more than cover what I planned.

The rooms are fully enclosed 12'x15' each.

Thanks.

Howard.

chris75 07-31-2008 02:56 PM

Quote:

Originally Posted by hhiibel (Post 144665)



Here's my question: Does the NEC put forth Amp requirements based on building size? If so, does this take building use into consideration? If so, what use/classification is my building?



Howard.

No, its based in the load the building requires... The inspector is flat out wrong...

hhiibel 07-31-2008 03:02 PM

I just looked at the 2005 NEC
 
what I found was table 20-102(i think that's the number) about non-dwelling farm building load calc. This table could be interpreted as saying the minimum load is set at 240V/60amps.

Chris,

It sounds like you're interpreting this table to be just the calc descibed. I wasn't positive about how to interpret the additional wording about 60 amps.

Thanks.

Howard.

hhiibel 07-31-2008 03:10 PM

I've been correct...
 
...my workmate whom visited the local bookstore with me during lunch has corrected me. It's table 22.102.

-howard

Stubbie 07-31-2008 05:48 PM

My guess is the inspector is confusing the requirement for the building disconnect to the size of the feeder. Reference NEC 225.39 the feeder... disconnecting means shall have a rating of not less than the calculated load as determined in art. 220 by the appropriate section. If there are more 2 branch circuits to supply the stable's needs then the disconnect needs to be rated 60 amps. This is not a requirement for the feeder ampacity however. In the end the disconnect cannot be rated less than the load to be served.

The inspector IMO is wrong if he is saying building size determines minimum feeder size.

Feeder conductor size to outbuildings such as barns, stables , shops etc is determined in art 220 Part III.

hhiibel 07-31-2008 06:34 PM

Keep em coming. I talk via phone to the inspector tomorrow.
 
Thanks Stubbie.

...this guy is it for the whole county. The only electrical inspector. Maybe, I'm mistaken but I'm entering into this on the assumption: whether he's correct or not, his word is it. Being that he's made this mistake, I'm assuming there's a purpose behind it. Meaning I don't think he's a dumb****, I think he's got an agenda. Call me paranoid.

Any Weld County, Colorado electricians out there? What's the story on County Inspector John Roberts?

Keep the posts coming. I'm desparate because I just signed a contract of sale and I can't afford to lose this deal. I'm thinking I'll be eating the $1500 spent so far and forking out the bucks to bring in power from the road. And what will this guy say next?

-howard

hhiibel 07-31-2008 07:13 PM

added some pics of barn
 
take a look. I've done some work since but the pics pretty well represent what it is.

-howard.

theatretch85 07-31-2008 08:10 PM

Could you show us some pictures of the power setup? Panel wiring and configuration. If it makes you feel any better, the farm I was at this last weekend I wired up for a ton of temporary power drops, only to find out in the main panel there was a 12/2 with ground UF cable that was serving 2 120 volt loads on the other end, needless to say the bare ground was the neutral/ground for this stable and was quite a shocking experience when I found that out. Its no where near wired properly the way its currently wired.

hhiibel 07-31-2008 08:42 PM

Not sure if I have pics.....
 
I'll try to dig up some pics.
I can't run out and take a pic because I've had to move out of state to earn a living.

In the meantime maybe some more details will suffice.

Here's the setup in total.
A 240V/50amp circuit was identified at the house panel (constructed 2005) and tapped as the source for the stable. This circuit was intented for a welder in the garage. I don't weld so what the hey - let's use it.

We (an electrician and I) sized for 240V/30amps delivered at the stable. He ordered the materials. I rented a trencher.

Electrician connected at the house and dropped the line in the trench. And wired into a beat up construction panel on a post that he supplied and I previously put in the ground. The construction panel is nothing to write home about. It has a covered four plug outlet I used for my power tools. Above the outlet is some sorta 6" round port hole thing with a clear front. It looks to have a big wire coming in from the left, connecting to what I guess to be a fuse in the middle and a big wire leading out to the right. Where the wires come from or where they go I don't know. Imagine looking in a port hole. Out the bottom of all this is a 2" round grey plastic conduit with the leads that he connected the lines to. It's been like this for about 12 months.

Inspector came out looked at the depth of the line and said OK. I buried the line and the requisite warning tape. I filled in the trench except for the remainder from the construction panel post to the building because I've yet to wire the building. So, to date, no wiring in the stable, no panel in the stable, no disconnect. Just a temp construction post with a 4 socket plug at about 30 feet from the building. And the remaining line coiled up and sitting on the ground.

Thanks.

-howard.

CowboyAndy 08-01-2008 06:50 AM

I would ask the inspector for a code refrence on it.

jrclen 08-01-2008 09:04 AM

Quote:

Originally Posted by hhiibel (Post 144734)
Here's the setup in total.
A 240V/50amp circuit was identified at the house panel (constructed 2005) and tapped as the source for the stable. This circuit was intented for a welder in the garage. I don't weld so what the hey - let's use it.

We (an electrician and I) sized for 240V/30amps delivered at the stable. He ordered the materials. I rented a trencher.

I'm a little confused. In the first paragraph it sounds like you are using a 50 amp circuit breaker to protect your new feeder. In the second paragraph you mention 30 amps. Are you connecting a #10 wire to the circuit breaker?

What is the wire size in the trench? What will you be using as a disconnect at the stable? A panel with a main breaker?

hhiibel 08-01-2008 11:22 AM

clarification...hopefully
 
Yes, I'll ask for a code reference.

I'm not sure what's at the house side. I think the electrician left the 240/50amp breaker at that end. The wire size I can't recall. It's big. It's copper. I think the run is 680 ft. At the time, using the equations I found on the web, I expected to see 36-37 amps at the stable. I haven't measured it. There is no disconnect at the stable end. There will be when the wiring is complete. Currently there is no wiring in the stable. All that's at the stable end is a construction post with a four plug outlet which is 30ft from the stable.

Another thing that's coming to mind, isn't there some sorta maximum allowed drop? I think we were just about at it.

Thanks.

Howard.

hhiibel 08-01-2008 07:51 PM

no call yet...
 
inspector hasn't called.

but maybe the issue is there's a 50amp breaker at the house end and his test ran up the amps and threw it before he saw 60amps and that means it doesn't meet the 60amp disconnect requirement. Hey, I'm just guessing. I don't even know what a disconnect is. I'm figuring it's a manual lever. Nah, he wouldn't have conducted a test like that. Such a test sounds dangerous - no one home, stress a remote line from the house. Nope he wouldn't do that.

-howard.

jrclen 08-02-2008 09:19 AM

Quote:

Originally Posted by hhiibel (Post 145029)
inspector hasn't called.

but maybe the issue is there's a 50amp breaker at the house end and his test ran up the amps and threw it before he saw 60amps and that means it doesn't meet the 60amp disconnect requirement. Hey, I'm just guessing. I don't even know what a disconnect is. I'm figuring it's a manual lever. Nah, he wouldn't have conducted a test like that. Such a test sounds dangerous - no one home, stress a remote line from the house. Nope he wouldn't do that.

-howard.

You are correct. There is no such test. A disconnect is a means for disconnecting, or turning off, the electricity. A circuit breaker can serve as a disconnect. Your 50 amp breaker in the house is the "over current protection device" for the feeder (wire) in the trench. At the stable end you need a disconnect. A 60 (or 100) amp circuit breaker in the panel in the stable will be that disconnect. That breaker can be bigger than the 50 because it is functioning only as a disconnect and not as a OCPD. The 50 protects the circuit against overload and short circuit.

Unless there is a state or local code requiring it, there is no rule telling you how much electricity you must install to a stable. That is determined by the load expected. You could very well install a single 20 amp circuit to the stable if the load was say some lights and a receptacle outlet. I think there is a misunderstanding in what the inspector actually said. Or meant. Asking him is the only way to resolve this. He might have simply had a problem with your temporary box.

Let us know what you find out. Call him again.

Something else you might want to know is about voltage drop. You don't get current drop on a long run of wire, you get voltage drop on the wire. So for any given load (amps) your voltage will be reduced. We try to limit that voltage drop to 5% at the end (where the outlet is).

http://www.electrician2.com/calculat...culatoradv.htm

Scroll down to a handy calculator. Pay attention to wire size and type, circuit voltage, temperature, distance, and estimated actual load.

hhiibel 08-08-2008 12:19 PM

Hi, I've spoken with the inspector. He seems willing to work with me. I wasn't able to pin him down on the minimum amps required by code, partly because I liked what I was hearing and I didn't want to press him. Hearing that I wasn't planning on needing more that 60amps 120V, he said he could work with that. He's suggesting a pole in the ground with a 100amp cutoff and an equipment ground. Then run two 120V lines into the stable. So, I'll be getting a new permit and I can feel confident that what I've done will work for the next owner. My wire is #2 alum. It's 3 wires so from the above site, I'm guessing its 208V 3wire 3phase? The one way run is 680ft. Just as I had calculated before, at 35amps, I'm just at the 5% drop. I'm expecting that 35amps becomes 70amps of 120V. Correct?


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