For ungrounded PV DC systems, the grounding electrode requirements apply under which NEC section?

• A. 250.169
• B. 250.166
• C. 690.45
• D. 250.122

Answer: (A)

Grounding electrode requirements for an ungrounded PV DC system are addressed in NEC 250.169. This section covers how a grounding electrode system is established for systems that are not bonded to earth on the DC side (and for separately derived systems), outlining how the grounding electrode conductor is connected to the grounding electrode system and bonded to other metallic parts. It’s the place in the code that tells you the places and methods to establish a reliable earth reference for an ungrounded PV installation.

The other sections relate to different aspects of grounding. For example, PV-specific grounding on the equipment level is covered by 690.45, and sizing or bonding details of conductors are found in 250.122 and other parts of Article 250, but the explicit grounding electrode requirements for ungrounded PV systems are found in 250.169.