National Electrical Installation Standards

Standards as High as Your Own

Friday, July 17, 2020


Hope everyone is staying healthy during this COVID-19 pandemic. My question is simple, can an emergency circuit junction box be identified by magic marker with just the letters "EM" written on the box cover? We have inspectors that require the word "Emergency."

Mike Riley



Greetings Mike,

Thanks for the kind words. The NEC requires that enclosures (including boxes) for circuits of emergency systems be marked so, that they are readily identifiable as a component of an emergency system. This would typically necessitate the use of the word emergency. Note that the Code does not specifically require the word emergency, however, that’s the common method of meeting this requirement. A color code system (with a legend) or other means of permanent identification could also be used. The important thing to remember is that when the project is completed, those who encounter enclosures and equipment that are connected to the emergency system, will know without question that it is a component of and emergency system, because they are readily identifiable by the markings. That's the goal. See Section 700.10(A). To just use the markings "EM" might raise questions and might not be judged by the AHJ as "readily identifiable." The AHJ has the final responsibilities for interpreting the NEC rules and issuing approvals, as indicated in Section 90.4.

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