Kicked on inspection....am I missing something????

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JacksonburgFarmer

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We had a inspection last week, for a small job. We ran a 15a 125V multiwire circuit from a warehouse to an outbuilding for lts. and receptacles. One circuit was for lts, one for receptacles. #12 THHN, 2 hots, 1 nuet., 1 GRND.

I was in a hurry to finish, and forgot to put in the disconnecting means for the outbuilding. I had planned to use a double pole single throw switch, 20A rated for this. I was onsite the day of inspection installing this switch when the inspector showed up, and I explained to him what I was doing.

He failed me, I asked for code ref. and he replied 225.30. He wants a sub panel with a main, and branch circuit breakers in the outbuilding.

I read NEC as I can have two circuits in outbuilding so long as they are multiwire branch ckt. MET 225.30 I also have met 225.31 with my switch, am I missing something here?????

Oh yeah, Inspector is about 80 yrs old to......stubborn old cuss....:D
 

mcclary's electrical

Senior Member
Location
VA
In this case your MWBC only counts as one circuit. There's no need for an electrode, and you are correct in using the switch as the disconnect.
 

charlie b

Moderator
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Location
Lockport, IL
Occupation
Retired Electrical Engineer
I read NEC as I can have two circuits in outbuilding so long as they are multiwire branch ckt.
If that is the way you worded your statement to the inspector, you probably confused him. In fact, you cannot have two circuits to an outbuilding.


But that's OK, because you only have one. That one is a MWBC, but it is a single circuit. The last sentence in 220.30 (i.e., before sub-article A, "Special Conditions") says so. I would invite the inspector's attention to that sentence.
 

charlie b

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225.30 says, "....shall be supplied by only one feeder or branch circuit......" and I don't see where you meet any of the other conditions.
You don't need to. Look at the last sentence before those other conditions are listed.

 

infinity

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Location
New Jersey
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So he cited 225.30 which means he's made one mistake:

225.30 Number of Supplies.
Where more than one building or other structure is on the same property and under single management, each additional building or other structure that is served by a branch circuit or feeder on the load side of the service disconnecting means shall be supplied by only one feeder or branch circuit unless permitted in 225.30(A) through (E). For the purpose of this section, a multiwire branch circuit shall be considered a single circuit.
He's correct regarding the disconnect:

225.36 Suitable for Service Equipment.
The disconnecting means specified in 225.31 shall be suitable for use as service equipment.
Exception: For garages and outbuildings on residential property, a snap switch or a set of 3-way or 4-way snap switches shall be permitted as the disconnecting means.
You do not need a GES at the outbuilding:

250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s).
(A) Grounding Electrode. Building(s) or structure(s) supplied by feeder(s) or branch circuit(s) shall have a grounding electrode or grounding electrode system installed in accordance with Part III of Article 250. The grounding electrode conductor(s) shall be connected in accordance with 250.32(B) or (C). Where there is no existing grounding electrode, the grounding electrode(s) required in 250.50 shall be installed.
Exception: A grounding electrode shall not be required where only a single branch circuit, including a multiwire branch circuit, supplies the building or structure and the branch circuit includes an equipment grounding conductor for grounding the normally non?current-carrying metal parts of equipment.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
We ran a 15a 125V multiwire circuit from a warehouse to an outbuilding for lts. and receptacles.

I read NEC as I can have two circuits in outbuilding so long as they are multiwire branch ckt.
As long as you meant 1209/240, and the origination breaker is a 2p or handle-tied.
 

S'mise

Senior Member
Location
Michigan
So he cited 225.30 which means he's made one mistake:

He's correct regarding the disconnect:

You do not need a GES at the outbuilding:

Nice post Rob. I love it when articles are posted verbatim...and I don't have to go look stuff up :)

Just one question; You said "he's correct regarding disconnect" but i believe the op said he installed a snap. Snap switchs are fine on a mwbc, right?
 
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mivey

Senior Member
Nice post Rob. I love it when articles are posted verbatim...and I don't have to go look stuff up :)

Just one question; You said "he's correct regarding disconnect" but i believe the op said he installed a snap. Snap switchs are fine on a mwbc, right?
I don't think that would work. A warehouse does not sound like a residence.
 

infinity

Moderator
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Location
New Jersey
Occupation
Journeyman Electrician
Nice post Rob. I love it when articles are posted verbatim...and I don't have to go look stuff up :)

Just one question; You said "he's correct regarding disconnect" but i believe the op said he installed a snap. Snap switchs are fine on a mwbc, right?


As mentioned in the OPand by some others, "from a warehouse to an outbuilding", that pretty much eliminates the snap switch idea.
 
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