9-89 Log #3086 NEC-P09 Final Action: Accept in Principle
(404.2(C) Exception No. 2 (New) )
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TCC Action: It was the action of the Correlating Committee that the panel
reconsider the new Exception No. 2 regarding the use of the words “most
areas” with respect to enforceability.
This action will be considered as a public comment.
Submitter: Frederic P. Hartwell, Hartwell Electrical Services, Inc. / Rep.
Massachusetts Electrical Code Advisory Committee
Recommendation: Insert a new exception as follows:
Exception No. 2: Where multiple switch locations control the same lighting
load in an interior room or space, a grounded conductor of the lighting circuit
shall not be required at each such location if one has been provided at one or
more switching points that is (are) visible from most areas within the room
including all principal entry points. Where a switch controls a receptacle load
or a lighting load that does not serve a habitable room or bathroom, or where
automatic control of lighting has been provided or the switch is not within the
lit area, a grounded circuit conductor shall not be required
Substantiation: The 2011 NEC did a good job of framing what is in effect a
wiring method exception, which avoids the neutral provision requirement in
instances where it can be easily added in the future. However, this provision is
sorely lacking an application exception addressing instances where an
occupancy sensor would be redundant, excessive, or impossible to install.
Unfortunately, this question was not addressed by CMP 9, largely because no
public comments mentioned it.
If a three-way switch loop controls the lighting in a space, and the switches
both see the room, why force a grounded conductor into every switch location?
Very frequently three-way switches will be arranged in a two-gang arrangement
where one of them will be on the opposite side of a wall from the illuminated
space it controls; how could that switch ever be replaced by an occupancy
detector? Note that 210.70 requires switch control of lighting loads in a space,
but the switch does not need to be in that space.
In addition, although 210.70 (A)(1) Exception No. 1 clearly allows switch-
controlled receptacles to substitute for luminaire outlets in dwellings, and this
substitution is entirely unregulated in other occupancies, no occupancy sensor
will ever likely be listed for use with receptacle outlets because the character of
the connected load is inherently uncontrollable in many aspects. Some
switches, such as closet door-jamb switches, control loads for which occupancy
sensors are not appropriate. Some wiring designs use conventional snap
switches wired to turn lights off if needed, but in series with an occupancy
sensor in the ceiling. This allows for automatic lighting control, but also a
means to force the lights off in an occupied room in order to show slides on a
screen. The proposal completes the action CMP 9 took for the 2011 cycle by
addressing these issues.
Panel Meeting Action: Accept in Principle
Revise the submitter’s wording to read as follows:
Exception No. 2: Where multiple switch locations control the same lighting
load in an interior room or space, a grounded circuit conductor of the lighting
circuit shall not be required at each such location if one has been provided at
one or more switching points that is (are) visible from most areas within the
room including all principal entry points. Where a switch controls a receptacle
load or a lighting load that does not serve a habitable room or bathroom, or
where automatic control of lighting has been provided or the switch is not
within the lit area, a grounded circuit conductor shall not be required.
Panel Statement: CMP 9 corrected the term “grounded conductor” to
“grounded circuit conductor”.
Number Eligible to Vote: 12
Ballot Results: Affirmative: 12