Equipment installed in hazardous (classified) locations shall be marked to show the _____.
a) class
b) group
c) temperature class
d) all of the above
See answer and applicable Code reference
The correct answer is: d) all of the above
Article 500 focuses on electrical equipment installed in hazardous (classified) locations. As noted in Sec. 500.8(C), equipment shall be marked with the information specified in (1) through (5).
"(1) The marking shall specify the class(es) for which the equipment is suitable."
"(3) The marking shall specify the applicable material classification group(s) in accordance with 500.6."
"(4) The marking shall specify the temperature class or operating temperature at a 40°C ambient temperature, or at the higher ambient temperature if the equipment is rated and marked for an ambient temperature of greater than 40°C."
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.