Doug Miller wrote:
In , wrote:
Scott Lurndal wrote:

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Section 410-31 of the NEC (1999 Edition) states:

Fixtures shall not be used as a raceway for circuit conductors.

Exception #1: Fixtures listed for use as a raceway
Exception #2: Fixtures designed for end-to-end assembly to
form a continuous raceway or fixtures connected
together by recognized wiring methods shall be permitted
to carry through conductors of a 2-wire or multiwire
branch circuit supplying the fixtures.
Exception #3: One additional 2-wire branch circuit separately supplying
one or more of the connected fixtures described in
exception
#2 shall be permitted to be carried through the fixtures.

Branch-circuit conductors within 3 inches of a ballast within the ballast
compartment shall have an insulation temperature rating not lower than
90 degrees C such as Types RHH, THW, THHN, THHW, FEP, FEPB, SA and XHHW.

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Most consumer grade flourescents aren't listed as raceways. That pretty
much leaves exception #2 as the guidance for this application. It also
limits
you to 2 two-wire or 1 three-wire and 1 two-wire branch circuits for the
string of fixtures.


Scott.

There is only 1 15A branch circuit. However, I had planned for it to
"split" through 3 switches in the switchbox and pass the resultant 5
wires--3 hot, 1 neutral, 1 ground, through the fixtures as necessary to
power them. If I understand correctly, this would qualify as a single
2-wire branch circuit, wouldn't it?

Absolutely. It's still one circuit, and it's still a "two-wire branch circuit"
despite there being four wires (the ground is not counted) because your three
hots are derived from the same point.

In any event, since the exception permits a multi-wire branch circuit, that
particular point is moot anyway. It's clearly a single circuit: there's only
one single-pole breaker.

TYVM!
Bill

Thank you for your confirmation Doug!




Do note the "recognized wiring methods".

Which would include, presumably, being connected by a properly-installed
section of EMT.

Please also be aware that the temperature rating of the conductors being
passed through must be at least 90c (THHN should suffice, but never use NM or
NM-B)

scott