Code Change Summary: A new code section was added to address electronic lighting control switches.

New code Section 404.22 was added in part II of the 2017 NEC^® which deals with the actual construction of the switch. Even though the construction of a switch is more of a manufacturer requirement, inspectors and electrician will share in the responsibility of enforcing and applying the code section.

Note: The grey highlighting for modified code sections and the N representing a new code section are misleading for those reading 404.22 from a first printing of the 2017 NEC^®. The entire section is new but the first printing indicates that only a portion of the text and the exception is new.

The new requirement aligns with and provides supporting language for the new changes in 404.2(C) which address electronic lighting control devices that require a neutral return path in order for the circuitry in the switch to function.

Now, electronic lighting control switches are not permitted to introduce current on the equipment grounding conductor during normal operation. This will force manufacturers to create electronic lighting control switches (like occupancy sensors) with a neutral terminal so that return current is not normally returned on the equipment ground. The requirement to not introduce current on the equipment grounding conductor becomes effective on January 1, 2020.

The new exception allows electronic lighting control switches to introduce current on the equipment grounding conductor only for replacements and retrofit applications in accordance with the new exception to 404.2(C). switches used for this application must be listed and marked for use in replacement or retrofit applications only.

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 2017 NEC^® edition of NFPA 70.