225.41 Emergency Disconnects.
Code Change Summary: A new section requires an emergency disconnect.
Section 225.41 is new in the 2023 NEC® and provides a new requirement to have an emergency disconnect for one-and two-family dwelling units supplied by an outside feeder or branch circuit (similar to the requirements in Section 230.85 for services).
This new code section is under Part II of Article 225 which applies to buildings or other structures supplied by feeders or branch circuits.
Not all “dwelling units” have their own electrical service. A detached guest house for example might be supplied by a feeder originating in an electrical service panelboard located at the main house.
The 2020 NEC® first introduced a requirement in Section 230.85 to have an emergency disconnect at one-and two-family dwelling units. This was to ensure that first responders have a suitable exterior disconnecting means in the event of natural disaster, fire, flooding and the like. A service disconnect switch or main circuit breaker located outside of the home can serve this purpose.
Whether a dwelling unit is supplied by a service or through a feeder, first responders still need a way to disconnect power to the dwelling if the situation warrants the need to.
Below are some of the key points from the new code language in Section 225.41:
- The disconnect required by this section must be installed in a readily accessible outdoor location on or within sight of the dwelling unit.
- The disconnect must have a short-circuit current rating equal to or greater than the available fault current.
- If more than one disconnecting means is provided, they must be grouped.
- The disconnecting means requires special marking, and the marking must be in compliance with NEC® Section 110.21(B).
- The disconnect must be marked “EMERGENCY DISCONNECT”.
- The marking or label must be located on the outside front of the disconnect enclosure with red background and white letters that are at least ½ inch high.
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.
2020 Code Language:
This code section did not exist.
2023 Code Language:
N 225.41 Emergency Disconnects. For one-and two-family dwelling units, an emergency disconnecting means shall be installed.
(A) General.
(1) Location. The disconnecting means shall be installed in a readily accessible outdoor location on or within sight of the dwelling unit.
(2) Rating. The disconnecting means shall have a short-circuit current rating equal to or greater than the available fault current.
(3) Grouping. If more than one disconnecting means is provided, they shall be grouped.
(B) Identification of Other Isolation Disconnects. Where equipment for isolation of other energy source systems is not located adjacent to the emergency disconnect required by this section, a plaque or directory identifying the location of all equipment for isolation of other energy sources shall be located adjacent to the disconnecting means required by this section.
(C) Marking. The disconnecting means shall be marked as EMERGENCY DISCONNECT.
Markings shall comply with 110.21(B) and all of the following:
(1) The marking or labels shall be located on the outside front of the disconnect enclosure with red background and white text.
(2) The letters shall be least ½ inch high.