Bill wrote:


Continuing to research my question, evidently low THD is better for
the components in the lighting system (capacitors, etc) and may
provide lower cost in the form of the longer life for the system.


Pitiful question: If 8 fluorescent fixtures are wired in a series, and
the ballast in one of them fails, do all of the lights go out? Assume a
"modern" fixture.

You don't wire them in series. You wire them in parallel. End of story.
It would be quite foolish to wire them in series.


If the answer to the question above is yes, this suggests "Lew's
wiring design" should be wired (using 12-3 THHN) with 2 parallel
(pairs of) circuits with 4 fixtures wired on each row. Then if one
of the fixtures went bad only two of them would go out (either the
ones on L1 or the ones on L2 in a given row). Is this correct?

Just wire them all in parallel.


Alternately, I could use 8 parallel circuits, 2 for each row, then if
one of the luminaire's failed, then it, and it alone, would go out.


Hey - you got it! Though 8 circuits would be crazy. You're looking at
maybe 2 circuits in your garage. Multiple switched runs, but all of them on
1 or 2 circuits.

Taking a step back, this is equivalent to wiring 2 branch circuits
each wiring 8 fixtures in parallel. Everything basically correct?


Yes.

--

-Mike-