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Friday, September 23, 2022

Question:

Hello Code Friends, 250.30C states if the Separately Derived System (SDS) is located outside, the grounding electrode connection shall be made at the source location. If the SDS (customer-owned transformer) is located outside, does it matter if the system bonding jumper is installed at the transformer or the main bonding jumper is made at the first disconnecting means?

Thank you,

John Bayduss

A

Answer:

Hello John, thanks for the great question. Section 250.30(C) requires a grounding electrode connection to be made at an outdoor separately derived system. In addition, the installation shall comply with Section 250.30(A) for grounded systems. The last sentence of Section 250.30(A)(1) requires the systems bonding jumper to be installed at the grounding electrode connection for outdoor sources. To maintain compliance with Section 250.30(C) and 250.30(A)(1) the system bonding jumper and grounding electrode connection will both need to be in the outdoor separately derived system source. 

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