Overview

Sensitive electronic devices can be damaged by voltage surges. The electronics in GFCIs, AFCIs, and smoke detectors render these critical devices subject to damage should a voltage surge occur. This could potentially cause a problem, especially in areas where occupants sleep. The risk of a lighting surge damaging a smoke detector, and then starting a fire is cause for concern. To lessen the risk, the 2023 NEC now requires surge protection on not only the service, but the feeder supplying areas where people sleep.

Applying the 2023 Code

Section 215.18 has been added to the 2023 NEC, which covers Surge Protection. This new section requires a surge-protective device (SPD) to be installed on the load side of any feeder supplying dwelling units, dormitory units, guest rooms and guest suits of hotels and motels, and areas of nursing homes and limited-care facilities used exclusively as patient sleeping rooms. The SPD is required to be Type 1 or Type 2, and shall have a minimum nominal discharge current of 10kA. Section 215.18 also requires any distribution equipment that is to be replaced be updated to include surge protection,. This means that if any panels supplied by a feeder are replaced, surge protection must be installed. Keep in mind that this is in addition to the service also requiring surge protection – so, yes, there could be multiple surge protectors installed within the electrical system.

What’s New for the 2023 NEC?

2020 NEC

In the 2020 NEC Section 215.18 did not exist

2023 NEC

215.18 Surge Protection.

(A) Surge-Protective Device.
Where a feeder supplies any of the following, a surge-protective device (SPD) shall be installed:
(1) Dwelling units
(2) Dormitory units
(3) Guest rooms and guest suites of hotels and motels
(4) Areas of nursing homes and limited-care facilities used exclusively as patient sleeping rooms

(B) Location.
The SPD shall be installed in or adjacent to distribution equipment, connected to the load side of the feeder, that contains branch circuit overcurrent protective device(s) that supply the locations specified in 215.18(A).

(C) Type.
The SPD shall be a Type 1 or Type 2 SPD.

(D) Replacement.
Where the distribution equipment supplied by the feeder is replaced, all of the requirements of this section shall apply.

 
(E) Ratings.
SPDs shall have a nominal discharge current rating (In) of not less than 10kA.