What is in this article?:
- What's Wrong Here?
- Find the Answer
Hint: Go ahead and throw on another coat of paint.
Find the Answer
This is the result of many years of painting at a hotel in San Diego. The numerous layers of paint have put the clamp behind a thick layer of insulation. Although it may never be called upon to do its job, this ground clamp would fail miserably if it ever were.
As per 250.12 of the 2005 NEC, “Nonconductive coatings (such as paint, lacquer, and enamel) on equipment to be grounded shall be removed from threads and other contact surfaces to ensure good electrical continuity or be connected by means of fittings designed so as to make such removal unnecessary.” For additional information on ground clamps, see 250.8, 250.10, and 250.70.