Is Main breaker panel and grounding required in separate Agricultrical building

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howardrichman

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I'll be wiring a new livestock barn w/ 70A subpanel for lighting and tub water heaters. Feeders are from existing one family house. Will panel need main breaker, ground conductor, and 2 ground rods? Not sure if code was changed in the last few years.

Thank you;
HR...
 
A main breaker is only required if you have more then 6 breakers. A four wire service is required on a sub panel. Two grd rods are required unless you can prove your dirt is so good that you only need one.That varies depending on jurisdictions. Check out Art 547
 
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Isnt a disconnect required at the second structure. I think he is referring to that. It does not need to be overcurrent protection but its less expensive to install a MB panel if ofcourse its nearest the point of entry. Also he mentioned "water" will equipotential grounding be of concern.
 
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FREEBALL said:
Isnt a disconnect required at the second structure.
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Buck is correct, if there are no more than six breakers (handles) a single main is not required, see article section 225.33(A)and (B) for this application.

Roger
 
I thought that referred to services not feeders
I dug this up from previous posts






charlie b


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Join DateFeb 2003LocationSeattle, WAPosts17,177
OK. You figured out that since this is a separate building, it needs a disconnecting means. You figured out that the breaker in the house panel will not count. But that doesn?t mean that the garage panel must have a main breaker. One way to meet the requirement is by placing an enclosed disconnect (or breaker) on the outside wall of the garage, or on the wall just inside. But do keep in mind the rules that govern the separation of neutrals and grounds, that govern the connection of equipment grounding conductors for garage circuits, and that require the garage to have its own grounding electrode system. ​

Charles E. Beck, P.E., Seattle
Comments based on 2014 NEC unless otherwise


​
 
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FREEBALL said:
I thought that referred to services not feeders
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It also applies to buildings supplied by a feeder. See 225.30 through 225.33. If you have six breakers or less in the sub-panel, then you don't need one single disconnecting means.
 
Ive been reading more on this and I really thought this was only applicable to services but I am seeing that it is not. What a great learning experience. I still don't see why you wouldn't want a disconnect and the original post didn't really say if there was more than 6 breakers/circuits but I keep coming back to the rule of " For all other installations, the feeder or branch-circuit disconnecting means shall have a rating of not less than 60 amperes". Which says to me that grouped 20 amp breakers does not qualify and you need a minimum 60 amp disconnect for the feeder.
 
roger said:
Did you read the article section I gave you?

Roger
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Yes but still seems confusing can it be that there is the potential that there could be more than 6 breakers in the future. I have always been installing mains for 60 amp and above now the panels were 12 space or more but only had 3 or 4 circuits in them at time of install, So if we install a 6 circuit 100 amp rated panel we would not need a disconnect, this is how Im understanding it. Whats to say you place a 12 circuit panel and additional circuits aren't added in the future. I guess this is whats bugging me. I was used to the 6 disconnect rule for services which had the disconnects at the point of service meter stack what have you. Thanx again Im digging lol
 
FREEBALL said:
Ive been reading more on this and I really thought this was only applicable to services but I am seeing that it is not. What a great learning experience. I still don't see why you wouldn't want a disconnect and the original post didn't really say if there was more than 6 breakers/circuits but I keep coming back to the rule of " For all other installations, the feeder or branch-circuit disconnecting means shall have a rating of not less than 60 amperes". Which says to me that grouped 20 amp breakers does not qualify and you need a minimum 60 amp disconnect for the feeder.
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Before you go to 225.39(D) read the last two sentences in 225.39(A)

Roger
 
FREEBALL said:
Ive been reading more on this and I really thought this was only applicable to services but I am seeing that it is not. What a great learning experience. I still don't see why you wouldn't want a disconnect and the original post didn't really say if there was more than 6 breakers/circuits but I keep coming back to the rule of " For all other installations, the feeder or branch-circuit disconnecting means shall have a rating of not less than 60 amperes". Which says to me that grouped 20 amp breakers does not qualify and you need a minimum 60 amp disconnect for the feeder.
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You need to read the part that precedes that:

225.39 Rating of Disconnect
The feeder or branch-circuit disconnecting means shall have a rating
of not less than the calculated load to be supplied, determined
in accordance with Parts I and II of Article 220 for branch circuits,
Part III or IV of Article 220 for feeders, or Part V of Article 220
for farm loads. Where the branch circuit or feeder disconnecting
means consists of more than one switch or circuit breaker, as
permitted by 225.33, combining the ratings of all the switches or
circuit breakers for determining the rating of the disconnecting
means shall be permitted. In no case shall the rating be lower than
specified in 225.39(A), (B), (C), or (D).
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FREEBALL said:
Yes but still seems confusing can it be that there is the potential that there could be more than 6 breakers in the future.
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We cannot control what happens after we leave a job. Let's say you have a piece of equipment that requires a 70 amp fused disconnect. You will have to install a 100 amp disconnect and fuse it at 70 amps. What guarantee do you have that someone will not come along in the future and install 100 amp fuses?

Roger
 
ok I did, read over it but he stated he is installing a 70 feeder in an agricultural building. Wouldn't that be covered under 225.39D really curious now because 225.39a states for a single branch cir 15 amp. But he is installing what I assume is a 240v 70 amp feeder. Which would require in my mind a disconnect rated for atleast 60 amp. Sorry if Im being persistant but Im really curious.
 
FREEBALL said:
ok I did, read over it but he stated he is installing a 70 feeder in an agricultural building. Wouldn't that be covered under 225.39D really curious now because 225.39a states for a single branch cir 15 amp. But he is installing what I assume is a 240v 70 amp feeder. Which would require in my mind a disconnect rated for atleast 60 amp. Sorry if Im being persistant but Im really curious.
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In post #11 I meant to say "read the last two sentences in 225.39" and that is what Pharon quoted in post #12. I confused you when I added the "(A)"

Roger
 
ok so he installs 3 15 amp breakers for conversation sake this is lower than his 70 amp feeder size, provided this is his calculated load. He would have to install a disconnect? and if the total switches are more than 6 he would have to install a disconnect?
 
I get what your saying and it was a great tour of the code and I will do more reading, no doubt, but I think a solid feeder install like what was mentioned should require a main disconnect if not for practicality, NEC, but for safety sake. Im sure your the same way and only noting what code allows, but it seems code isn't always whats practical. Albeit its safe but if you can say up to 6 breakers is ok for feeder disconnect, but not make a final stance on length of service cable allowed from meter to main panel, leaving it up to AHJ on services, where is the intent leading. Seems theres a lot allowed to be interpreted. Thanx by the way did you see my post on the generac issue any ideas. thanx jeff
 
FREEBALL said:
ok so he installs 3 15 amp breakers for conversation sake this is lower than his 70 amp feeder size, provided this is his calculated load. He would have to install a disconnect?
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He could use a MWBC and handle ties to make it a one or two circuit installation.
FREEBALL said:
and if the total switches are more than 6 he would have to install a disconnect?
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Correct or a main breaker.

Roger
 
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Thanks for replies. The panel comes w/ a 100 amp main breaker in a 10/20 panel. I'll separate the grounds as in any sub panel, and also install 2 ground rods. building is wood on dirt floor so no other grounding should be required. The 100 amp breaker should be classified as just a disconnecting means.
HR...
 
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