Overview

It is common practice for a single service to supply up to six disconnecting means, as limited by Section 230.71. In previous editions of the National Electrical Code, this requirement, this limitation was specifically directed towards traditional service equipment, but excluded items such as metering centers and motor control centers, which can be used as service equipment under certain conditions. The 2023 NEC has clarified in 230.71(B) that metering centers and motor control centers are to be counted as a disconnecting means. Further clarification was made regarding the use of transfer switches used in conjunction with the main service.

Applying the 2023 Code

Each service or set of service entrance conductors are permitted to feed two to six service disconnecting means. Previously per Section 230.71(B), these were permitted to be separate enclosures within a main service disconnecting means, panelboards with main service disconnecting means, switchboards where there is only one service disconnect, or service disconnects in switchgear/metering centers where each disconnect is located in a separate compartment. The 2023 NEC has updated this section to require barriers to be provided between each vertical section of switchboards, to include transfer switches as equipment counting as one of the six disconnects, to add metering centers with a disconnect in each metering center, and to add motor control centers with a single disconnect. Additionally, an exception was added permitting service equipment installed per previous editions of the NEC to have a maximum of six service disconnecting means. These changes will ensure electrical personnel safety not only when servicing traditionally service equipment, but service equipment of all different types.

What’s New for the 2023 NEC?

2020 NEC

In the 2020 NEC Section 230.71(B) read as follows (less the informational notes):

(B) Two to Six Service Disconnecting Means.
Two to six service disconnects shall be permitted for each service permitted by 230.2 or for each set of service-entrance conductors permitted by 230.40, Exception No. 1, 3, 4, or 5. The two to six service disconnecting means shall be permitted to consist of a combination of any of the following:
(1) Separate enclosures with a main service disconnecting means in each enclosure
(2) Panelboards with a main service disconnecting means in each panelboard enclosure
(3) Switchboard(s) where there is only one service disconnect in each separate vertical section where there are barriers separating each vertical section
(4) Service disconnects in switchgear or metering centers where each disconnect is located in a separate compartment

2023 NEC

In the 2023 NEC Section 220.41 now reads as follows (less the informational note):

(B) Two to Six Service Disconnecting Means.

Two to six service disconnects shall be permitted for each service permitted by 230.2 or for each set of service-entrance conductors permitted by 230.40, Exception No. 1, 3, 4, or 5. The two to six service disconnecting means shall be permitted to consist of a combination of any of the following:

(1) Separate enclosures with a main service disconnecting means in each enclosure

(2) Panelboards with a main service disconnecting means in each panelboard enclosure

(3) Switchboard(s) where there is only one service disconnect in each separate vertical section with barriers provided between each vertical section to maintain the inadvertent contact protection required in 230.62 based on access from the adjacent section(s)

(4) Service disconnects in switchgear, transfer switches, or metering centers where each disconnect is located in a separate compartment

(5) Metering centers with a main service disconnecting means in each metering center

(6) Motor control center(s) where there is only one service disconnect in a motor control center unit and a maximum of two service disconnects provided in a single motor control center with barriers provided between each motor control center unit or compartment containing a service disconnect to maintain the inadvertent contact protection required in 230.62 based on access from adjacent motor control center unit(s) or compartment(s)

Exception to (2), (3), (4), (5), and (6): Existing service equipment, installed in compliance with previous editions of this Code that permitted multiple service disconnecting means in a single enclosure, section, or compartment, shall be permitted to contain a maximum of six service disconnecting means.