When bonding metal parts and equipment of electric sign or outline lighting systems, when is it permissible to omit the bonding connection to an equipment grounding conductor?

  1. Never.
  2. Only when the nominal voltage is less than 250V to ground.
  3. Only when the nominal voltage is more than 250V to ground.
  4. When the remote metal parts of section signs or outline lighting systems are supplied only by a remote Class 2 power supply.


Answer: D

Article 600 focuses on electric sign and outline lighting installations. Grounding and bonding requirements are noted in Sec. 600.7.

Typically, the metal parts and equipment of signs and outline lighting systems shall be bonded together and to the associated transformer or power supply equipment grounding conductor serving it. However, an exception to 600.7(B)(1) states, "When bonding metal parts and equipment of electric sign or outline lighting systems, it is permissible to omit the bonding connection to an equipment grounding conductor when the remote metal parts of section signs or outline lighting systems are supplied only by a remote Class 2 power supply."

Owen is the owner and president of National Code Seminars and the holder of master electrician certifications in 46 states. He can be reached at necexpert@aol.com.