Code Quiz of Day

Single-Throw Knife Switches

Dec. 9, 2014

The rules for the position and connection of switches are outlined in Sec. 404.6.

Single-throw knife switches shall be installed so that gravity will tend to close the switch.

a) True
b) False

See answer and applicable Code reference

The correct answer is: b) False

You can find the Code requirements for switches in Art. 404. The rules for the position and connection of switches are outlined in Sec. 404.6. As per 404.6(A), "Single-throw knife switches shall be placed so that gravity will not tend to close them. Single-throw knife switches, approved for use in the inverted position, shall be provided with an integral mechanical means that ensures that the blades remain in the open position when so set."

About the Author

Mike Holt

Mike Holt is the owner of Mike Holt Enterprises (www.MikeHolt.com), one of the largest electrical publishers in the United States. He earned a master's degree in the Business Administration Program (MBA) from the University of Miami. He earned his reputation as a National Electrical Code (NEC) expert by working his way up through the electrical trade. Formally a construction editor for two different trade publications, Mike started his career as an apprentice electrician and eventually became a master electrician, an electrical inspector, a contractor, and an educator. Mike has taught more than 1,000 classes on 30 different electrical-related subjects — ranging from alarm installations to exam preparation and voltage drop calculations. He continues to produce seminars, videos, books, and online training for the trade as well as contribute monthly Code content to EC&M magazine.