A disconnecting means for X-ray equipment shall have adequate capacity for at least ____% of the input required for the momentary rating of the equipment or ____% of the input required for the long-time rating of the equipment, whichever is greater.
a) 50 / 100
b) 50 / 125
c) 100 / 100
d) 125 / 125
See answer and applicable Code reference
The correct answer is: a) 50 / 100
Article 660 covers all X-ray equipment operating at any frequency or voltage for industrial or other non-medical or non-dental use. As noted in the first sentence of Sec. 660.5, "A disconnecting means of adequate capacity for at least 50% of the input required for the momentary rating, or 100% of the input required for the long-time rating."
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.
