7.4 Service Equipment, Disconnecting Means, Surge Protection & GFPE (2026 NEC Article 230)
Key Takeaways
Under the 2026 NEC 230.70(A)(1), the service disconnect for a one- or two-family dwelling must be readily accessible and outdoors, either on the dwelling or within sight and not more than 50 ft from it.
One- and two-family dwelling service disconnects must be marked EMERGENCY DISCONNECT in white letters at least ½ in. high on a red background, permanently affixed and not handwritten.
Each service may have one disconnecting means, or two to six disconnects grouped at one location under the conditions of 230.71 and 230.72.
The service disconnect for a one-family dwelling must be rated at least 100 A, 3-wire (230.79(C)), and for other installations generally at least 60 A (230.79(D)).
GFPE is required for each service disconnect rated 1000 A or more on a solidly grounded wye system over 150 V to ground, such as 480Y/277 V, with a maximum setting of 1200 A (230.95).
What changed for 2026
DLI's 2026 NEC adoption review highlighted Article 230 changes that directly affect Minnesota service work:
- 230.70(A)(1): for one- and two-family dwellings, the service disconnecting means must be readily accessible and located outdoors, either on the dwelling or within sight of it (110.29: visible and not more than 50 ft away).
- 230.85 deleted: the separate 2023 "emergency disconnect" rule was folded into 230.70. The outdoor service disconnect is the emergency disconnect.
- Markings: service disconnects are marked SERVICE DISCONNECT (other than one- and two-family dwellings) or EMERGENCY DISCONNECT (one- and two-family dwellings), and other energy-source disconnects not located at the service must be listed on a plaque or directory at the service disconnect.
- 230.70(F): a remote-control device, such as a pushbutton for a shunt-trip breaker, is not a service disconnecting means.
- 230.46: an Informational Note recognizes the marking "SVC" as equivalent to "suitable for use on the line side of the service equipment" for splicing and tap devices.
Location of the service disconnect (230.70(A))
| Occupancy | Location |
|---|---|
| One- and two-family dwellings | Readily accessible, outdoors, on the dwelling or within sight of it |
| All other buildings | A readily accessible location either outside the building or inside nearest the point of entrance of the service conductors |
| Any building | Not in bathrooms |
Each service disconnect must be permanently marked to identify it as a service disconnect, and the marking must meet 110.21(B): durable for the environment, not handwritten, and permanently affixed.
Marking details
| Building type | Marking |
|---|---|
| Other than one- and two-family dwellings | SERVICE DISCONNECT, on or adjacent to the disconnect |
| One- and two-family dwellings | EMERGENCY DISCONNECT, on the outside front of the enclosure, white letters at least ½ in. high on a red background |
| Other energy sources (PV, generators, ESS) not adjacent to the service disconnect | A plaque or directory at the service disconnect identifying the location of each source disconnect |
Number and grouping of disconnects (230.71 and 230.72)
Each service may have one disconnecting means, or two to six disconnecting means where each is in a separate enclosure, or in switchgear, switchboards, or panelboards with barriers as permitted by 230.71(B). Multiple disconnects must be grouped at one location and each marked to show the load it serves. Disconnects for fire pumps, emergency systems, legally required or optional standby systems, and parallel power production systems must be installed remote from the normal service disconnects, so first responders do not open them by accident.
Number of service-entrance conductor sets (230.40)
Each service drop, set of overhead service conductors, set of underground service conductors, or service lateral may supply only one set of service-entrance conductors. The exceptions cover common layouts:
- A building with more than one occupancy may have one set of service-entrance conductors run to each occupancy or group of occupancies.
- Where separate disconnect enclosures are grouped at one location and supply separate loads from one service drop or lateral, one set of service-entrance conductors may supply each or several of the enclosures.
- A one-family dwelling and its accessory structures may each have one set of service-entrance conductors from a single service drop or lateral.
- Two-family and multifamily dwellings and multiple-occupancy buildings may have one set to supply the common house loads covered in 210.25.
- One set connected ahead of the normal service disconnect may supply the systems that 230.82 allows on the supply side, such as fire pump equipment or a power production source.
Rating and type (230.76 to 230.80)
| Rule | Requirement |
|---|---|
| Operation (230.76) | Manually operable switch or circuit breaker, or a power-operated switch or breaker that can also be opened by hand |
| Indicating (230.77) | Plainly indicates whether it is open or closed |
| Rating (230.79) | One-circuit installations at least 15 A; two-circuit installations at least 30 A; one-family dwellings at least 100 A, 3-wire; all others at least 60 A |
| Combined rating (230.80) | Where there are multiple disconnects, their combined rating may not be less than the rating required for a single disconnect |
The ampacity of the ungrounded service-entrance conductors may not be less than the minimum disconnect rating in 230.79 (230.42(B)).
Service equipment and meter sockets
- 230.66: service equipment must be listed (or field evaluated) and marked suitable for use as service equipment.
- Meter sockets are not service equipment, but they must be listed and rated for the voltage and current rating of the service. A 2026 exception (230.68) lets a fire pump meter socket be sized to the circuit rating rather than the fire pump service current.
- 230.62(C) barriers: service equipment must have barriers so that no uninsulated, ungrounded service busbar or terminal is exposed to inadvertent contact while servicing load terminations.
- 230.82: only listed items may be connected on the supply side of the service disconnect, such as meters and meter sockets, meter disconnect switches rated for the available fault current, instrument transformers, surge arresters and Type 1 SPDs, and conductors for emergency, standby, fire pump, and power production sources when they have their own disconnecting means and overcurrent protection. The 2026 NEC reorganized this list.
Surge protection (230.67)
All services supplying dwelling units must have a surge-protective device (SPD), Type 1 or Type 2, that is an integral part of the service equipment or located immediately adjacent to it (or, where permitted, at the next level of distribution). The 2023 edition extended this to dormitory units, guest rooms and guest suites of hotels and motels, and areas of nursing homes and limited-care facilities. When service equipment is replaced, an SPD must be installed. The 2026 NEC also requires an SPD where existing service equipment is reconnected to a replacement mobile or manufactured home (550.51).
Overcurrent protection (230.90 and 230.91)
Each ungrounded service conductor must have overload protection by an OCPD in series, with a rating not higher than the conductor ampacity, except as permitted by 240.4(B) and for up to six circuit breakers or sets of fuses whose combined ratings may exceed the conductor ampacity. The service OCPD must be an integral part of the service disconnecting means or located immediately adjacent to it (230.91).
Ground-fault protection of equipment (230.95)
GFPE is required for solidly grounded wye services of more than 150 V to ground (such as 480Y/277 V) for each service disconnect rated 1000 A or more:
- maximum ground-fault setting 1200 A;
- maximum time delay 1 second for ground-fault currents of 3000 A or more;
- the system must be performance tested when first installed, following the manufacturer's instructions, and a written record kept for the AHJ.
GFPE is not required for a continuous industrial process where a nonorderly shutdown would create additional hazards, and it is not permitted on fire pump services. A 208Y/120 V service never requires GFPE under 230.95, because it is only 120 V to ground.
Worked example: a new Minnesota home
A new single-family house gets a 200 A, 120/240 V underground service with rooftop PV.
- Install a meter-main (combination meter socket and main breaker) on the outside wall. The main breaker is the outdoor, readily accessible service disconnect required by 230.70(A)(1).
- Mark it EMERGENCY DISCONNECT with white letters at least ½ in. high on a red background.
- The 200 A rating exceeds the 100 A minimum of 230.79(C).
- Provide a Type 1 or Type 2 SPD at the service equipment (230.67).
- The PV system disconnect is on the garage wall, not next to the meter-main, so install a plaque or directory at the service disconnect showing where the PV disconnect is.
Under the 2026 NEC, where must the service disconnect for a new one-family dwelling be located?
In a readily accessible outdoor location, on the dwelling or within sight of it
Inside the dwelling, nearest the point of entrance of the service conductors
Anywhere within 25 ft of the meter, inside or outside
In the garage, if the garage is attached
A new 1200 A, 480Y/277 V service has a single main circuit breaker. What does 230.95 require?
No GFPE, because GFPE applies only to services rated over 2000 A
GFPE set at no more than 1200 A, performance tested when installed
GFPE set to trip at 30 mA on each feeder breaker
A Class A GFCI built into the main service breaker
What is the minimum rating of the service disconnecting means for a one-family dwelling under 230.79?
60 A
150 A
100 A
200 A
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