NEMA 250
Enclosures for Electrical Equipment (1000 Volts Maximum)
Published by National Electrical Manufacturers Association (NEMA)
The CFR incorporates NEMA 250 by reference, which makes the edition it names part of the regulation. The CFR requires the edition it names, which may not be the newest. To enforce any other edition, the agency must publish the change in the Federal Register.
The edition the CFR requires
NEMA 250-2018, 2018
As the CFR lists it: “NEMA 250-2018, Enclosures for Electrical Equipment (1000 Volts Maximum), 2018 (“NEMA 250”)”
How to read it
- Where to get itNEMA standards ↗
A free or purchased copy may not be the edition the CFR names; check it against the edition above. Every incorporated standard can also be inspected at the National Archives (NARA) and at the agency named in the section that lists it.
NEMA 250 is copyrighted by its publisher; RegKnot shows its title and the editions the CFR names, not its text. Read from the eCFR's incorporation-by-reference sections, current as of October 26, 2026. The regulation text governs. All standards the CFR requires.