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215.18(A)-(E), 225.42(A)-(E) and 230.67(A)-(E) Surge Protection Requirements Expanded

Revision/New

Leviton Comment: This guides purpose is to simplify and condense the NEC changes. In that spirit we have merged Articles 215.18(A)-(E), 225.42(A)-(E) and 230.67(A)-(E). This was done because the text is almost the same in each article. The text just resides in different Articles of the NEC and while few words differ in (A), the intent is the same. The broader significance of these changes is the fact that dormitories, guest rooms and nursing homes have been added to the list of places that need surge protection.

Change Summary

  • Surge protection requirements have been expanded to dormitories, guest rooms/suites of hotel/motels and sleeping rooms of nursing homes and limited care facilities.

NEC®Text

Articles: *215 Feeders;
*225 Outside Branch Circuits and Feeders;
*230 Services
215.18; 225.42; 230.67 Surge Protection.
(A) Surge-Protective Device. Where a feeder and all services 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 and service equipment, connected to the load side of the feeder, that contains branch circuit overcurrent protective device(s) that supply the location specified in 215.18(A), 225.42(A) and 230.67(A).
Informational Note: Surge protection is most effective when closest to the branch circuit. Surges can be generated from multiple sources including, but not limited to, lightning, the electric utility, or utilization equipment.
(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 10 kA.

Material taken from the National Electric Code. is reprinted with permission from NFPA 70., 2023 edition. National Electrical Code®, Copyright 2022, National Fire Protection Association, Quincy, MA. All rights reserved.

Expert Analysis

A new section has been added to clarify the proper protection of areas served by feeders and outside branch circuits that are extended distances away from services which can can result in limited surge protection. The new section addresses the surge-protective device, location, type, replacement, and ratings.

The current exception in 230.67 achieves the goals of this exception by not requiring the surge-protective device at the service when surge protection is provided at each next level distribution equipment downstream towards the load.

It’s also worth noting that the required SPD’s nominal discharge rating must be at least 10 kA. This is a new and significant change from the previous 2020 NEC language.

Figure 1

Leviton Solution

Type 2 Surge Protection Devices (SPDs) would typically be the type of device most often associated with this Code article. See Type 2 Below.

Here we have provided an explanation of the different levels of surge protection and their applications:

Figure 2

Type 1 and Type 2 SPDs shunt external surges that originate from utilities or disturbances outside the home or facility. Type 2 SPDs can protect for both internal and external surges when located at the branch. Type 3 SPDs can shunt surges that originated internally within the home or facility. So a comprehensive strategy for surge protection typically involves a Type 1 or Type 2 SPD and also a Type 3 SPD at point of use.

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