Code Change Summary: New language points the code reader to Articles 230 and 250 for additional requirements.
In the 2023 NEC®, Section 705.11 has seen many revisions stemming from a move to recognize the conductors between a line side connection ahead of a service disconnect and an interconnected power production source disconnect as “service conductors”. New Section 705.11(D) is evidence of this movement.
In the 2023 NEC®, Section 705.11(D) is titled “Service Disconnecting Means” and requires a disconnecting means in compliance with Parts VI through VII of Article 230 to be provided to disconnect all ungrounded conductors of a power production source from the conductors of other systems.
It is important to remember that the connection of power production sources to the supply side of an existing service disconnect does not make the production sources an “electrical service”. A service rated disconnecting means is required for each line-side connection to the service conductors as required in 230.82(6) which is in Part VI of Article 230, but this service rated disconnect does not disconnect the utility supplied electrical service from the premises wiring system and is not included in the maximum permitted number of service disconnects in 230.71.
Another change in 2023 is the new language in 705.11(E) pertaining to grounding and bonding for interconnected power sources connected on the supply side of a service disconnect. The intent behind the public input resulting in the new language was to bring in language originally accepted by code panel 4 for this section during the 2020 NEC® code development process that never actually made it to print.
The first draft language accepted for 705.11(D) in 2023 mimicked the balloted 2020 first draft language and stated: “All metal enclosures, metal wiring methods, and metal parts associated with the power source output conductors in 705.11(B) shall be bonded in accordance with 250.92(B). This metal equipment shall be connected to the grounding electrode system for the service at the power source disconnecting means with only one of the methods in 705.11(D)(1) or (D)(2). Where the power source uses a grounded conductor, 705.11(D)(1) shall apply”.
Note that the 2023 public input was pointing to existing 2020 NEC® code language in 705.11(B) which was only about the power source output circuit conductors from the service conductors point of connection to the first overcurrent protection device.
During the 2023 second draft meetings, the final language for 705.11(D) was moved to (E) and shortened to require all metal enclosures, metal wiring methods, and metal parts associated with the service connected to a power production source to be bonded in accordance with Parts II through V and VIII of Article 250. This final language retains the intent of the first draft public input but points the code reader to specific parts of Article 250 for these requirements rather than repeating them again in Article 705.
Section 250.92(B) is in Part V of Article 250 and requires the following:
250.92(B) Method of Bonding at the Service. Bonding jumpers meeting the requirements of Article 250 shall be used around impaired connections, such as reducing washers or oversized, concentric, or eccentric knockouts. Standard locknuts or bushings shall not be the only means for the bonding required by this section but shall be permitted to be installed to make a mechanical connection of the raceway(s).
Electrical continuity at service equipment, service raceways, and service conductor enclosures shall be ensured by one or more of the following methods:
(1) Bonding equipment to the grounded service conductor by an applicable method in 250.8(A)
(2) Connections made up wrenchtight using threaded couplings, threaded entries, or listed threaded hubs on enclosures
(3) Threadless couplings and connectors if made up tight for metal raceways and metal-clad cables
(4) Other listed devices, such as bonding-type locknuts, bushings, or bushings with bonding jumpers
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 language did not exist.
2023 Code Language:
N 705.11(D) Service Disconnecting Means. A disconnecting means in accordance with Parts VI through VII of Article 230 shall be provided to disconnect all ungrounded conductors of a power production source from the conductors of other systems.
N 705.11(E) Bonding and Grounding. All metal enclosures, metal wiring methods, and metal parts associated with the service connected to a power production source shall be bonded in accordance with Parts II through V and VIII of Article 250.
Based on the 2023 NEC, which of the following is required to disconnect all ungrounded conductors of a power production source from the conductors of other systems?
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