Is this configuration NEC-compliant? 75kVA xfmr, 480-208/120V, 110A OCPD on the primary (for primary only protection per 450.3B). Double-tapped secondary, one circuit feeding a 150A MCB panel, the other feeding a 100A MCB panel, both circuits less than 25' total length, but one panel is not in the same room as the xfmr.
Xfmr Circuit per 240.21
- Thread starter msteiner
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- Connecticut
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- Engineer
Can't tell if this complies with 240.21, as you haven't told us the size of the circuit conductors.
As long as your install is per NEC and the tap rules of 240.21(C) you should have no problem.
240.21(C)states "a set of conductors or EACH set of conductors" so you can have multiple sets from one transformer as long as each fits the tap rules which do not include the transformer being with sight.
I see many installs with the transformer on the opposite side of the wall as the panel.
240.21(C)states "a set of conductors or EACH set of conductors" so you can have multiple sets from one transformer as long as each fits the tap rules which do not include the transformer being with sight.
I see many installs with the transformer on the opposite side of the wall as the panel.
LarryFine
Master Electrician Electric Contractor Richmond VA
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- Henrico County, VA
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- Electrical Contractor
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