System bonding jumper

[Dave Bruner]

According to 250.104(D)(2) a separately derived system with building steel. The connection shall be made at the same point on the separately derived system as the grounding electrode conductor. Should this be done inside the x-fmr or can it be done in the first disconnecting means.

 

[augie47]

Welcome to the Forum !

This help ?

 

[Dave Bruner]

system bonding jumper

system bonding jumper

If xo is bonded as in first half of picture, is it considered a parallel path if it is done also like second half of picture.

 

[GoldDigger]

If xo is bonded as in first half of picture, is it considered a parallel path if it is done also like second half of picture.

Yes. Parallel paths for an EGC are not a problem, but putting in both jumpers creates a parallel path for the normal operation current which should be flowing only in the neutral/grounded conductor.

POCO is allowed to do this sort of thing on their side of the service point, but a separately derived system is not a service.

 

[augie47]

Your Code reference is 250.30(A)(1) {'08}
Exception #2 discusses where a parallel path is not established.