Does the NEC require a surge protector on a house?

Under the 2020 NEC, yes. Section 230.67(A) was new in the 2020 edition and requires that all services supplying dwelling units be provided with a surge-protective device (SPD). It must be a Type 1 or Type 2 device per 230.67(C), installed as an integral part of the service equipment or immediately adjacent to it per 230.67(B). Whether this applies in your area depends on which edition your jurisdiction has adopted.

Does replacing a panel or service equipment trigger the SPD requirement?

Yes. NEC 2020 230.67(D) states that where service equipment is replaced, all of the requirements of 230.67 apply. So swapping out an existing dwelling service panel or service disconnect triggers the surge-protective device requirement even though the original installation predated it. An existing service whose equipment is not being touched is not made noncompliant retroactively.

What type of SPD satisfies NEC 230.67?

NEC 230.67(C) requires a Type 1 or Type 2 SPD. A Type 1 SPD is permanently connected and permitted on the line side or load side of the service disconnect overcurrent device with no separate overcurrent protection required. A Type 2 SPD is permanently connected on the load side of the service disconnect overcurrent device, including at a branch panelboard. A Type 3 plug-in point-of-use device (a surge strip) does not satisfy 230.67.

Where does the service SPD have to be located?

Per NEC 230.67(B), the SPD must be an integral part of the service equipment or located immediately adjacent to it. There is an exception: the SPD is not required to be in the service equipment if an SPD is provided at each next-level distribution equipment downstream toward the load. If the service feeds more than one downstream panel, that exception requires an SPD at every one of them, not just one.

Does a whole-house surge protector replace GFCI or AFCI protection?

No. A service surge-protective device under 230.67 protects equipment from transient overvoltages such as lightning and utility switching surges. GFCI protection (210.8) protects people from shock, and AFCI protection (210.12) guards against arcing faults that start fires. They are separate requirements, and a dwelling still needs its GFCI and AFCI devices in addition to the service SPD.

Surge-Protective Device (SPD) Requirement Calculator

Pick the service and the work scenario to see whether NEC 2020 230.67 requires a surge-protective device, which Type satisfies it, where it has to mount, and whether replacing existing service equipment triggers the rule. The 230.67 service-SPD mandate was new in the 2020 National Electrical Code (NEC), and a panel swap is one of the places it catches people.

Service

What does the service supply?

Work scenario

Planned device (optional)

SPD type

Installed location

How to use this calculator

Choose what the service supplies: a dwelling unit (the 2020 mandate) or only non-dwelling occupancies.
Pick the work scenario: a new service, a replacement of existing service equipment (230.67(D)), or an existing service you are not touching.
Optionally select the SPD Type you plan to use so the tool can confirm it against 230.67(C) and reject a Type 3 strip.
Optionally pick the installed location to see the 230.67(B) rule and the next-level-distribution exception, then read the notes for the full citation chain.

NEC reference

The requirement is NEC 2020 230.67. Subsection (A) requires a surge-protective device on all services supplying dwelling units; subsection (B) sets the location (integral to or immediately adjacent to the service equipment, with an exception for an SPD at each next-level distribution equipment downstream); subsection (C) requires a Type 1 or Type 2 SPD; and subsection (D) makes the whole section apply where service equipment is replaced. 230.67 was added in the 2020 edition, so a jurisdiction still on the 2017 NEC has no service-SPD mandate, and the 2023 edition expands the covered occupancies and adds a minimum-rating subsection, both outside this tool's 2020 scope.

Results are for reference only. Verify against the applicable adopted edition of the NEC and consult a licensed electrician for code compliance.

What NEC 2020 230.67 says

Section 230.67 is short and has four parts. It applies to the service, not to individual branch circuits, which is why it belongs with the service and disconnect rules rather than with the GFCI and AFCI device sections.

Subsection	What it requires
230.67(A)	An SPD on all services supplying dwelling units.
230.67(B)	Integral to or immediately adjacent to the service equipment; or, by exception, at each next-level distribution equipment downstream.
230.67(C)	The SPD shall be a Type 1 or Type 2 device.
230.67(D)	Where service equipment is replaced, all of 230.67 applies.

Table values and section numbers are referenced for identification only, not reproduced from the NEC verbatim.

Type 1 versus Type 2: which one and where

230.67(C) accepts either a Type 1 or a Type 2 SPD, and the difference is where it connects. A Type 1 SPD is permanently connected between the utility transformer secondary and the service disconnect overcurrent device, so it can land on the line side or the load side of the main and needs no separate overcurrent protection. A Type 2 SPD is permanently connected on the load side of the service disconnect overcurrent device, which includes a position at a branch panelboard. A Type 3 SPD is a plug-in, point-of-use device, usually cord-connected at least 30 ft of conductor from the service, and it does not satisfy the 230.67 service requirement.

The replacement trigger catches remodels

230.67(D) is the part electricians miss. A dwelling built under the 2014 or 2017 NEC has no SPD, and the code is not retroactive, so it stays compliant as installed. But the moment the service equipment is replaced, such as a panel change or a service upgrade, 230.67(D) makes the entire section apply, and the new installation needs a Type 1 or Type 2 SPD. Treat a service-equipment swap on a 2020-code job as an SPD job.

Frequently asked questions

Is a plug-in surge strip enough for code?

No. A plug-in surge strip is a Type 3 point-of-use device, and 230.67(C) requires a Type 1 or Type 2 SPD at or near the service. A Type 3 device can be used as supplementary protection for sensitive electronics, but it does not satisfy the service requirement.

Do commercial or industrial services need an SPD?

Not under the 2020 NEC. 230.67(A) scopes the service-SPD mandate to services supplying dwelling units. The 2023 edition expands it to dormitory units, guest rooms and guest suites, and certain nursing-home and limited-care sleeping areas, so on a 2023-code job re-check the scope for the occupancy you are serving.

Does a multifamily building need SPDs?

A service supplying dwelling units falls under 230.67(A), so a service to an apartment or condo building that feeds dwelling units is covered. Where the SPD sits follows 230.67(B): at the service, or an SPD at each next-level distribution panel under the exception.

Does this size the SPD's rating?

No. This tool answers the 230.67 requirement, Type, and location. Match the SPD's voltage rating to the nominal system voltage and confirm its short-circuit current rating against the available fault current per the manufacturer's instructions and 110.3(B); fault-current analysis is outside this tool.

Related calculators

GFCI Breaker Sizing Calculator: the NEC 210.8 ground-fault requirement by location and GFCI breaker sizing.
AFCI Requirement & Breaker Sizing Calculator: the NEC 210.12 arc-fault requirement for dwelling rooms.
Service Disconnect Number & Rating Calculator: the 230.71 one-to-six service disconnect rule and rating.
Service Size Calculator: the dwelling service and feeder load calculation.

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