All references are based on the 2020 edition of the NEC, unless otherwise noted.
The idea of providing a disconnect on the exterior of one- and two-family dwelling units for emergency personnel to have the ability to turn off the power quickly (and without the need to enter a burning or flooded building with all of the circuits still energized) sounds like a great idea in theory. However, the practical applications of the requirements in Sec. 230.85 need to be examined closely to see which types of installations would be Code-compliant.
The first sentence of this rule requires “all” service conductors to “terminate in a disconnecting means” installed in a readily accessible outdoor location. Three options are provided as a possible means for complying with this requirement. Installers may need to be very particular in the arrangement of these installations in order to provide a Code-compliant installation.
For example, service conductors terminated in the meter socket in the Photo would not comply, since they are not “terminated in a disconnecting means.” The conductors on the load side of the meter socket would comply, since they are “terminated” in the service disconnecting means installed adjacent to the meter enclosure. Does this mean the service disconnect must be installed in the circuit ahead of the meter socket in order to provide a Code-compliant installation? The answer is “yes” based on the literal wording in the first sentence of the rule. But I don’t believe that is the intent.
Conductors on the load side of the service disconnect are feeders, which are not required to comply with Sec. 230.85. Does Sec. 230.85 apply to the grounded neutral conductor too? Well, the first sentence does state in part “all service conductors shall terminate in disconnecting means.” If a circuit breaker is used as the disconnecting means, the literal wording requires the ungrounded conductors and the neutral conductor to be disconnected by the circuit breaker too. I’m not so sure the intent of this rule was to have the neutral connected in this way.
Using a meter disconnect or other listed switches or disconnects may provide some quandaries too. For example, the conductors terminated in a meter disconnect may comply, but the conductors on the load side of a separately installed meter socket technically do not comply with the literal wording, since they do not “terminate in a disconnecting means” as required in the first sentence of the rule.
While the idea behind this new requirement is a sound one, I think some wrinkles need to be ironed out. If in doubt, it is best to have a discussion with your local authority having jurisdiction (AHJ).
