Code Change Summary: New language and an informational note added to address nonmetallic cables concealed in buildings connected to agricultural buildings with livestock confinement capabilities.

In the 2023 NEC^® code language was added to Section 547.26 to prohibit nonmetallic cables from being concealed within walls and above ceilings of buildings (i.e., offices, lunchrooms, ancillary areas, etc.) or portions thereof, which are contiguous with or physically adjoined to livestock confinement areas.

Additionally, a new informational note mentions that rodents and other pests are common around agricultural installations and often damage nonmetallic cables by chewing the cable jacket and conductor insulation concealed within walls and ceilings of livestock containment areas.

Keep in mind that Article 547 applies to agricultural buildings or parts of a building or adjacent areas of similar or like nature as specified in 547.1(A) or (B), but some buildings or portions of buildings might serve multiple purposes. This code change addresses nonmetallic cables concealed within walls and above ceilings of buildings like offices, lunchrooms, areas that are ancillary to the main occupancy, or portions thereof, which are “contiguous” (adjacent, neighboring, bordering, abutting, connected to, touching) with or physically adjoined to livestock confinement areas.

If a building near an agricultural location is not contiguous to a livestock confinement area, then this code language does not apply.

A concealed cable that has been chewed to the point of insulation failure creates a fire hazard.

Even exposed cables in other nearby structures that are cut off and not connected to agricultural buildings (as in the image) can be easy targets for rodents and when compromised, can create a major shock hazard.

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 2023 NEC^® edition of NFPA 70.