Inspector507
Super Member
6sunset6 said:
What part seems to be a violation of the NEC® ?
Electric service to barn
- Thread starter fishpick
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What part seems to be a violation of the NEC® ?
6sunset6
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I never heard of a farm meter but thats a good way to do it. I can see where the ground wire would not be required. It's sort of like another house on the transformer with it's own main panel. I think distance is the key. The second panel wants to be so far away that neutrals and grounds will never be in contact from one main to the other. But I have never seen that distance defined. What ever the inspector wants.
6sunset6
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I knew if I kept this up I would have to dig it out. NEC
Start with section 250-21a General comment to avoid current flow over grounding or grounded paths.
250-23 a explains that the premises service grounding electrode and the gounded service (neutral ) are tied together . It goes on to say that this connection shall not be made anywhere on the load side of the service disconnecting means. If you run a branch circuit out to the barn from this panel this means you cannot tie the nuetral to the ground anyplace else. That's why the screw that ties the neutral buss to the box it sits in is shipped loose. If its a main panel it goes in, if its a sub panel ,even in a barn it stays out. It is also the reason boxes have tapped holes to allow installation of separate groundbuss'.
There are many other sections that say ,in different ways that you must have grounding electrodes( long bars)
250-53 b could e confusing except that the box in the barn is NOT a service disconnect. I think this is the key. The Farm meter pan with two sets of lugs make the box in the barn a service and then the neutral buss is grounded there.
Start with section 250-21a General comment to avoid current flow over grounding or grounded paths.
250-23 a explains that the premises service grounding electrode and the gounded service (neutral ) are tied together . It goes on to say that this connection shall not be made anywhere on the load side of the service disconnecting means. If you run a branch circuit out to the barn from this panel this means you cannot tie the nuetral to the ground anyplace else. That's why the screw that ties the neutral buss to the box it sits in is shipped loose. If its a main panel it goes in, if its a sub panel ,even in a barn it stays out. It is also the reason boxes have tapped holes to allow installation of separate groundbuss'.
There are many other sections that say ,in different ways that you must have grounding electrodes( long bars)
250-53 b could e confusing except that the box in the barn is NOT a service disconnect. I think this is the key. The Farm meter pan with two sets of lugs make the box in the barn a service and then the neutral buss is grounded there.
Inspector507
Super Member
6sunset6 said:
Since you had to dig it out, now go read 250.32(b). If you run a grounding conductor, you isolate the two. If you elect not to, and there are no other metallic paths, you can bond the two together at the barn.
6sunset6
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I don't have a b but I have an older version of NEC.. It's pretty minor but I have been in the electrical gounding business a long time and I like to have safe in my mind instead of whether or not to run an extra wire. Personal preferance .
Inspector507
Super Member
6sunset6 said:
I understand, no prob. I've been in the electrical trade for many years myself, including enforcement of the NEC® for the last 18 years.
I think it was brought into the NEC® in 2002.
Eric_Phillips
Platinum Member
Fishpick,
They finally put in our electric and water. Where the two ran in the same place they put them both in the same trench with the water below frost and the electric at about 24". I was watching to see if he was going to drop his bobcat in the trench when patially filling it before putting the electric in. Then he told me he almost put the minitrackhoe in the ditch. He went to turn to get off the ditch and it nearly fell in. He had to fill the ditch back in, drive the hoe off and dig it back out from the side. He said that wasted him about an hour. I was more upset that I missed the show
. I ended up with 4 strands of #2 Al direct bury wire and two empty 1" PVC conduit. He will then sink the grounding rods and I will attach the ground leads and have it inspected before I drive them home. The reason for the 2 PVC was that he was supposed to put in 2" conduit and run the service line through that. Then I would have had extra space to run a light switch back to the house if I wanted to. Then have a spare conduit for the telephone. Since he wnet direct bury on the cable I made him put in two small conduits. They are all laying next to each other so I bet I am going to have some noise in the phone. I tried the cordless phones in intercom mode and I could not hear my wife in teh barn but she could heare me with no problems. We will see what works.
Eric
They finally put in our electric and water. Where the two ran in the same place they put them both in the same trench with the water below frost and the electric at about 24". I was watching to see if he was going to drop his bobcat in the trench when patially filling it before putting the electric in. Then he told me he almost put the minitrackhoe in the ditch. He went to turn to get off the ditch and it nearly fell in. He had to fill the ditch back in, drive the hoe off and dig it back out from the side. He said that wasted him about an hour. I was more upset that I missed the show
. I ended up with 4 strands of #2 Al direct bury wire and two empty 1" PVC conduit. He will then sink the grounding rods and I will attach the ground leads and have it inspected before I drive them home. The reason for the 2 PVC was that he was supposed to put in 2" conduit and run the service line through that. Then I would have had extra space to run a light switch back to the house if I wanted to. Then have a spare conduit for the telephone. Since he wnet direct bury on the cable I made him put in two small conduits. They are all laying next to each other so I bet I am going to have some noise in the phone. I tried the cordless phones in intercom mode and I could not hear my wife in teh barn but she could heare me with no problems. We will see what works.Eric
OP
fishpick
Platinum Member
Eric_Phillips,
Cool! Sounds like the phone works just fine
Tonight I'm planning on starting to do a bit of the electric project... got most of the pool grading done last night - so I'm on Honey-Do work release for the evening! Hope to pull the cable through the existing conduit back to the barn with a new LB and a expansion joint... that will get about 40' of the 130' job done
Maybe tonight we will even get the conduit in the garage set and up into the attic... which would be awesome!
I'll post progress and pics in the morning.
As for the discussion on the NEC - there are the 2 approaches in the 2 sections discussed - one is 3 wire - one is a 4 wire approach. I have never been a fan of having to float the neutral bus - that's why I chose the 3 wire route after talking with the inspector... for what I'm doing - and the type of expected draw - he actually was the one to "push" the 3 wire solution.
Cool! Sounds like the phone works just fine
Tonight I'm planning on starting to do a bit of the electric project... got most of the pool grading done last night - so I'm on Honey-Do work release for the evening! Hope to pull the cable through the existing conduit back to the barn with a new LB and a expansion joint... that will get about 40' of the 130' job done
Maybe tonight we will even get the conduit in the garage set and up into the attic... which would be awesome!
I'll post progress and pics in the morning.
As for the discussion on the NEC - there are the 2 approaches in the 2 sections discussed - one is 3 wire - one is a 4 wire approach. I have never been a fan of having to float the neutral bus - that's why I chose the 3 wire route after talking with the inspector... for what I'm doing - and the type of expected draw - he actually was the one to "push" the 3 wire solution.
Eric_Phillips
Platinum Member
I will be interested what the inspector says about my 4 wire system since we are using the same inspector. I assume you are not having any other metallic connections back to teh house? Since I think I will need to run a phone line I need the 4th wire.
Eric
Eric
OP
fishpick
Platinum Member
Last night got the project started - which ended up - through the evolutions of this posting to be different than expected.
I had (as Eric_Phillips stated) decided to have only the power out to the barn - no other cables - anything else I would want will be "wireless"... SO I decided to use the existing 2" conduit... as we started to pull out the existing wires (CAT5, coax, and a horry story of a single Romex run... we noticed that there was water in the conduit - and by water I mean A LOT...
Now - this was to be expected, in retrospect - since when the conduit was attached to the garage there was no expansion joint - and the LB snapped off - on the side of the house that gets all the rain...
So - hooked the air compressor up and blew out all the water we could...
Then - to get rid of the rest that wouldn't blow out - we put rags on a rope - about 3' apart and ran 4 of them through the conduit... first batch did a great job - second batch came out clean! We decided it was a cross between a colonoscopy and cleaning a gun!
Anyhow - got the #2 out into the barn through the conduit - up the inside of the garage wall between studs in conduit... a hairy turn in the attic made and a 10' section in the attic run...
Tomorrow night we finish the attic for sure, run down the garage wall and break into the basement... anything more than that is gravy...
I could post pictures of gray tubing... but I know this group - you all can close your eyes and imagine it...
I had (as Eric_Phillips stated) decided to have only the power out to the barn - no other cables - anything else I would want will be "wireless"... SO I decided to use the existing 2" conduit... as we started to pull out the existing wires (CAT5, coax, and a horry story of a single Romex run... we noticed that there was water in the conduit - and by water I mean A LOT...
Now - this was to be expected, in retrospect - since when the conduit was attached to the garage there was no expansion joint - and the LB snapped off - on the side of the house that gets all the rain...
So - hooked the air compressor up and blew out all the water we could...
Then - to get rid of the rest that wouldn't blow out - we put rags on a rope - about 3' apart and ran 4 of them through the conduit... first batch did a great job - second batch came out clean! We decided it was a cross between a colonoscopy and cleaning a gun!
Anyhow - got the #2 out into the barn through the conduit - up the inside of the garage wall between studs in conduit... a hairy turn in the attic made and a 10' section in the attic run...
Tomorrow night we finish the attic for sure, run down the garage wall and break into the basement... anything more than that is gravy...
I could post pictures of gray tubing... but I know this group - you all can close your eyes and imagine it...
Inspector507
Super Member
fishpick said:
No matter how well you glue it, moisture and water will always get into underground conduits. That's why the NEC® requires the wires installed in conduits underground to be rated direct burial.
gemini5362
Veteran Member
woodlot said:
Man, I sure wouldn't announce that in public, you'll have those unruly copper theives digging up your yard. You sure thats not AL wire?
Amen to that. I could build a shop for what that probably cost
gemini5362
Veteran Member
Cliff wire sizes double in diameter as you change size. the sizes go from ( just to pick a random starting point) 10, 8, 6, 4, 2, 0. with each smaller number being twice as big in diamater, then it starts back up again with 00 (2/0) 0000 (4/0) etc with each increase in the number of zeroes being a doubleing of the diameter when he says 4/0 that is just a shorthand for 0000 eventually it gets to where you just give the dimensions of the wire itself.Cliff_Johns said:
OP
fishpick
Platinum Member
For all the help - kind words - and opinion sharing... I couldn't let you guys (and gals too) not know how it turned out... so...
Bluebird Meadow Farms: The Barn Power Project : Details
Short version - it works great! Thanks for all your help... And there are pictures on the other end of that link!
Bluebird Meadow Farms: The Barn Power Project : Details
Short version - it works great! Thanks for all your help... And there are pictures on the other end of that link!
gemini5362
Veteran Member
fishpick said:
I saw the website thank you for the information. I am curious in the website it says you used #2 aluminum with a 100 amp breaker. I did not think that #2 aluminum was rated for 100 amps I figured you needed at least 1/0 or 2/0
or did you mean you used 2/0 wire ?
OP
fishpick
Platinum Member
It was - AL-URD Cable 3 Wire 2-2-4 100AMP... that's right from the Crown Electric receipt... which was right from what the electrical inspector told me to buy...
gemini5362
Veteran Member
buying what the electrical inspector tells you to is always one of the best ways to go. I am not an electrician so I would not try to tell someone they were wrong. Everything I read says that you have to go two wire sizes larger for aluminum than copper and if you are running 100 amp in copper it takes a size #2 gauge. Maybe one of the guys on here that have years of electrician experience can enlighten me.
mudcat
Platinum Member
gemini5362 said:
Maybe a code book would enlighten you.
schmism
Super Member
I put in ~60' of triplex 4/0 AL 200A underground and 150' of #2? triplex AL 100A underground this spring for my barn and trailer power....
You can balpark the 4/0 at ~4$ per foot and half that for the #2.... Copper is about 75% more.
To reloacate my meter base off the old house the is comming down i had to
set a new pole
move the meter base
buy a 200A disconnect for at the pole
buy wire
buy conduit/fittings for sections that stick out of the ground at the ends
rent trencher
pay fee to have utilty hook me up.
grand total on my project by my estimate is nearly $1000
gemini5362
Veteran Member
Maybe it would but since I really dont need it I probably will not buy one. However from what I have been told and what I have read aluminum wire will not carry as much current as copper wire. That is why you need two wire sizes bigger when you are running aluminum. If that is not the case I would welcome someone that knows explaining it. That would probably be more helpful than the comment that I should get a code book.mudcat said:
