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SDS with two disconnects in separate enclosures

Merry Christmas
Say I have an SDS transformer, feeding two sets of secondary conductors, each to separate disconnects as permitted by 240.21(C) and table 450.3(B) note 2. Typically, we can make the N-G bond for an SDS at either the transformer or the first disconnecting means. Then there is the exception allowing a bond on both ends for outdoor SDS's if there is no parallel path. But in this case, is it correct that there is no requirement to make the bond ONLY at the source of the SDS, despite the fact that a parallel path for neutral current between the two disconnect enclosures will be created if the bond is at the first disconnects?
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Allow me to emphasize the phrase "single point" in 250.30(A)(1) on the SBJ for an SDS:

. . . This connection shall be made at any single point on the separately derived system from the source to the first system disconnecting means
or overcurrent device . . .

Does that not preclude having SBJs in each disconnecting means in your example?

Cheers, Wayne
 
Allow me to emphasize the phrase "single point" in 250.30(A)(1) on the SBJ for an SDS:

. . . This connection shall be made at any single point on the separately derived system from the source to the first system disconnecting means
or overcurrent device . . .

Does that not preclude having SBJs in each disconnecting means in your example?

Cheers, Wayne
Yes I believe that does it. I read through the whole thing multiple times but jumped over that phrase I guess. Ok, so no flaw in 250.30!
 
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