230.85 Emergency Disconnects.
Code Change Summary: New code section. The 2020 NEC® will require an exterior emergency disconnect for one- and two-family dwelling units.
Until now, there has never been an NEC® requirement for an emergency disconnect to be located inside or outside of the home. In the 2020 NEC® there will be. This new code language ensures that first responders will have a suitable exterior disconnecting means in the event of natural disaster, fire, flooding and the like. Pulling the electrical meter because the main service disconnect is located on the inside of the home is not acceptable.
Existing residential service installations will likely be allowed to remain as they are, but new installations and service upgrades performed after the adoption of the 2020 NEC® will be required to incorporate a readily accessible exterior emergency disconnect. A service disconnect switch or main circuit breaker located outside of the home can serve this purpose.
This code change will have a huge impact in some states and may not be that big of a deal in others.
In the warmer states, the most common type of residential electric service installation includes an exterior all-in-one type meter/service panel, having a main circuit breaker (service disconnect) and the branch circuit breakers underneath (see image). The homeowner must run outside to reset a tripped circuit breaker. These service configurations will comply with the new code language.
In many of the colder states, a main breaker type service panel is located inside the home and supplied by a short run of service conductors from the utility meter, just on the opposite side of the exterior wall. It’s no fun to venture outside in the cold to reset a circuit breaker should one trip. These types of service configurations will only comply with the new code language if an emergency disconnect is installed outside.
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 2020 NEC® edition of NFPA 70.
2017 Code Language:
This code section did not exist.
2020 Code Language:
N 230.85 Emergency Disconnects.
For one- and two-family dwelling units, all service conductors shall terminate in disconnecting means having a short-circuit current rating equal to or greater than the available fault current, installed in a readily accessible outdoor location. If more than one disconnect is provided, they shall be grouped. Each disconnect shall be one of the following:
(1) Service disconnects marked as follows:
EMERGENCY DISCONNECT,
SERVICE DISCONNECT
(2) Meter disconnects installed per 230.82(3) and marked as follows:
EMERGENCY DISCONNECT,
METER DISCONNECT, NOT SERVICE EQUIPMENT
(3) Other listed disconnect switches or circuit breakers on the supply side of each service disconnect that are suitable for use as service equipment and marked as follows:
EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT
Markings shall comply with 110.21(B).