Change Summary

• The revision provides additional relief from the grouping requirements in 210.4(D)
• The words “or if the conductors are identified at their terminations with numbered wire markers corresponding to the appropriate circuit number” have been added to this exception
• These circuit numbers must be marked on corresponding common neutral conductor of a multiwire branch circuit at their terminations

Expert Analysis

The revision to this exception provides another practical means to qualify for relief from the general multiwire branch circuit grouping requirements of 210.4(D).
Information in the substantiation indicated that multiwire branch circuit conductors in commercial and industrial occupancies are often installed and identified with numeric wire markers on each individual conductor (typically adjacent to the circuit breaker and neutral bar).
Although the existing code requirement is adequate to accomplish grouping, this additional method is superior to the use of tape or cable tie bundling since those methods are often obscured by other conductors in a crowded panelboard gutter space. By installing the wire marker near the termination point, its corresponding multiwire branch circuit numbers will be readily evident.
It should be noted that the Code currently does not require that branch circuits be identified by circuit number. The various identification means for branch circuits is provided in 210.5(C)(2). The exception previously only relaxed this rule where the grouping of a multiwire branch circuit was obvious. The new text added to the exception provides another practical example of where the grouping can be easily achieved by installers and compliance can be more readily determined by electrical inspectors.