2011 NEC New Code Rule
Relating to Switch Circuits
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The 2011 NEC has added a new rule in regards to
switch circuits. NEC is the National Electrical Code which is applicable
to the United States.
That new code rule is...
404.2 Switch Connections
(C) Switches
Controlling Lighting. Switches controlling line-to-neutral lighting
loads must have a neutral provided at the switch location.
What that means is that at every switch location
there must be a grounded conductor (neutral) present regardless if there
is a need or not. Now a lot of us will scratch our heads on this one
just as I did when I first heard about it thinking why is there a
requirement to have a grounded conductor (neutral) present when the
switch circuit does not require one at every switch box. But as I
research this in more detail as to why this would be a requirement, I
start to understand the intent of the new rule. Modern times are getting
more into the use of timers, and so called green switches / controls
that can sense the presence of people and automatically turn off lights
or switch them off after a certain time set on the timers. Some users
will try to install these devices long after the original circuit was
wired. These special devices require a grounded conductor (neutral)
present to work. Using the equipment grounding conductor to take the
place of a grounded conductor (neutral) is not allowed. However some
people are tempted to do just that to enable the device to work.
The other side of the coin is that in a lot of
switch circuits some switch locations will not have an 'always on'
ungrounded conductor (hot) present which will not allow a timer / smart
switch to work anyway. Yet the new NEC rule still requires the grounded
conductor (neutral) to be present.
Like a lot of rules exceptions do
exist...
The grounded circuit
conductor shall be permitted to be omitted from the switch enclosure
where either of the following conditions in (1) or (2) apply:
(1) Conductors for switches controlling
lighting loads enter the box through a raceway. The raceway shall have
sufficient cross-sectional area to accommodate the extension of the
grounded circuit conductor of the lighting circuit to the switch
location whether or not the conductors in the raceway are required to be
increased in size to comply with 310.15(B)(3)(a).
(2) Cable assemblies for switches controlling
lighting loads enter the box through a framing cavity that is open at
the top or bottom on the same floor level, or through a wall, floor, or
ceiling that is unfinished on one side.
Also note that this section seems to
contradict code. As NEC 90.1(B) says: This Code contains provisions that
are considered necessary for safety. Compliance therewith and proper
maintenance results in an installation that is essentially free from
hazard but not necessarily efficient, convenient, or adequate for good
service or future expansion of electrical use.
Please view the following video that
explains the rule...
I would really recommend taking the time to watch
the above video in full as it does explain the new rule in detail
Please note the NEC (and this new rule) only
applies to the United States and this new rule does not apply to Canada
(is not in Canadian code yet). However that does not prevent you from
wiring your switch circuits to comply with this new NEC rule even if you
live in a location where the 2011 NEC does not have jurisdiction and may
come in handy in the future having a grounded conductor (neutral)
available even if one is not required for the current wiring
configuration.
For a switch that is a cut off for a furnace is not controlling a
lighting load, and therefore this rule does not apply.
This website is aimed at an international
audience with our main audience being the United States and Canada,
along with that not all the switch wiring options presented on this
website meet this new 2011 NEC 404.2 (c) rule but each switch article
will indicate if that wiring option does meet the 2011 NEC 404.2(C),
that will be indicated just bellow the 'switch wiring title' but above
the disclaimer, as well as in the menus.
Some switch wiring circuits will now require a 4
wire cable (plus bare) in order to comply with this new rule. On this
website those switch wiring options that used a 4 wire cable in order to
comply with this new rule has a 4th wire blue in color. From research it
seems to have two cable options available that is a 4 wire red / blue /
black / white (plus bare) cable and a red / black / white and white with
a red strip through it (plus bare). If you get the cable with the 4th
wire being the white with a strip through it, use that wire in place of
the blue wire indicated in the switch articles, and indicate at both
ends of that wire that it is being used as an ungrounded conductor by
wrapping a piece of black electrical tape at both ends of the wire on
this cable (you could also blue electrical tape).
Now 4 wire cables are available but you may have
to look around for it, and I suspect more places will be carrying it as
the demand rises due to this new NEC rule.
