Code Change Summary: New code section now requires certain generators to be listed.

Until now, the NEC^® has never required generators to be listed. Other codes require generators to be listed but not the NEC^®. Many generators have been listed for years even though NEC^® code language did not exist.

The original 2020 public input (code change proposal) requested ALL permanently installed generators to be listed. This public input was rejected since not all generators are listed and there are many specialized generators for which listing is not available. Additionally, product standards do not yet exist for medium voltage generators.

At the second draft meeting, new language was accepted to require all stationary generators rated 600 volts and less to be listed.

UL 2200 Standard for Stationary Engine Generator Assemblies covers stationary engine generator assemblies rated 600 volts or less that are intended for installation and use in ordinary locations in accordance with the National Electrical Code. The standard addresses safety concerns for both electrical and fuel control for electrical generating equipment. Requiring a listed generator ensures the unit will operate safely under normal and foreseeable abnormal conditions to prevent the risk of fire, electric shock, and other hazards. This is important especially considering generators are often exposed to the general public.

Below is a preview of the NEC^®. See the actual NEC^® text at NFPA.ORG for the complete code section. Once there, click on their link to free access to the 2020 NEC^® edition of NFPA 70.