jar546
Forum Coordinator
With so many different types of electrical equipment, more specifically cabinets and other assemblies, upon inspection we often don't know if ground lugs and bars are factory installed, field installed, or if they have proper metal-to-metal surface contact which is the purpose of NEC 250.12 - Clean Surfaces. Certain fittings, like locknuts and star washers, are engineered to maintain reliable electrical continuity through nonconductive coatings by ensuring a strong contact surface. The installer needs to secure these connections tightly, as this guarantees the locknut effectively establishes a solid electrical connection. This is one of the reasons why inspectors need to be familiar with changes in equipment and take a closer look at grounding and bonding during site visits.
Do you have a story to share about a violation you came across concerning NEC 250.12?
Do you have a story to share about a violation you came across concerning NEC 250.12?