Change Summary

• In addition to being marked with the purpose, disconnects are now required to identify the source of the branch circuit or feeder for the disconnect at the disconnecting means enclosure (other than one- or two-family dwellings).

Expert Analysis

A disconnecting means is required to be marked with a label to identify exactly what the disconnect is for. If the disconnect is installed right next to something like a motor and the wiring method goes right to the motor, no label is required as it is evident as to the purpose of the disconnect. This label or marking is required to be suitable for whatever environment the disconnect is installed such as outdoors. For the 2020 NEC this label or marking is also required to provide identification of the circuit source that supplies the disconnecting means. This identification of the circuit source does not apply to a disconnect installed at one- or two-family dwelling unit. By identifying the source of a circuit (branch circuit or feeder) at the disconnecting means enclosure, this will 110.22(A) Identification of Disconnecting Means Material taken from the National Electric Code® is reprinted with permission from NFPA 70®, 2020 edition. National Electrical Code®, Copyright 2019, National Fire Protection Association, Quincy, MA. All rights reserved. 10 bring this requirement in line with 408.4(B) for the same identification requirement for switchboards, switchgear, and panelboards.

Many times, in industrial, commercial, and multifamily dwellings with multiple disconnects located throughout the buildings and or around the premises, it can be difficult to locate the source of supply for an individual disconnect. The time-consuming task in locating the power supply source can be critical in an emergency situation and exasperating during normal maintenance operations. The added wording of “shall include the identification of the circuit source” requires the identification or marking to show a specific device and location. A general reference to a location such as “Electrical Room 2” will not be sufficient for this requirement. The final marking should require notation of specific devices. This power supply identification practice will enhance the safety for the electrical personnel who service these disconnects.