If the conductors are entirely outside the first building, then a disconnecting means for the first building is not required.
Medium Voltage Feeder Through a Building
- Thread starter msteiner
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mbrooke
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- United States
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I would agree then, no disconnecting means.
- Location
- Massachusetts
I would be very surprised if an AHJ would allow a MV feeder to pass through a building without following part II of 225 even if encased inside the slab from the start.
mbrooke
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Which would mean a disconnecting means?
Not necessarily. A feeder circuit starts from the load side of a disconnecting means. The cable staring from secondary side of transformer of OP till it is terminated in a disconnecting means is not so much a feeder cable as a service cable.The provision of Art.225 part II applies to feeder/branch circuits:
http://www.jade1.com/jadecc/courses/UNIVERSAL/NEC05.php?imDif=2554.0
mbrooke
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If its from the utility I would agree, if not I would say a branch feeder.
BTW, the disconnect in that link is wired wrong
- Location
- Illinois
- Occupation
- retired electrician
I have seen pictures of it being done after the building has been completed....they built form work around the conduit and poured concrete to a thickness of at last 2" all the way around the conduit. Of course a few extra supports were added to carry the additional weight of the concrete.
- Location
- Illinois
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- retired electrician
You can have feeder cables on the secondary side of the transformer as long as that transformer is on the load side of the service disconnect.
Making the cable a service cable and not a feeder cable increases the installation restrictions.
mbrooke
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Is the concrete mandatory?
- Location
- Massachusetts
Did it literally pass through the interior of a building without a disconnecting means?
You are correct, but what about tap rules to avoid a disconnecting means on the first building?
- Location
- Illinois
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- retired electrician
It was actually service conductors to the service disconnect that was inside the building and not "nearest the point of entrance", but the same type of thing could be done with a feeder conductor passing though a building.
- Location
- Illinois
- Occupation
- retired electrician
What tap rule would permit that?
- Location
- Illinois
- Occupation
- retired electrician
The concrete makes the conductors "outside of the building" to satisfy code rules.
Tap rule pertaining to unlimited length of feeder cable might apply but OP cable terminates on a transformer and not on a disconnecting means............
- Location
- Massachusetts
Yes and I have done service conductors like that.
But unless I am mistaken the OP has a feeder leaving building 1, passing through building 2 and onto power building 3.
In my opinion a disconnecting means is required at building 2 regardless of concrete encasement.
IMO2
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