Attempting to connect two #14 ground wires to a single ground screw in
single-tube Lithonia fluoresecent fixtures joined end-to-end resulted in
stripping the screw threads in the sheet steel fixture. Is it acceptable to
substitute the next larger size of self-tapping machine screw. Of course it
won't be green and will be cadmium or zinc plated.

Alternatively, a longer ground might be screwed through a nut on the
backside of the fixture but this would be inconvenient.

David Merrill

David Merrill wrote:
Attempting to connect two #14 ground wires to a single ground screw in
single-tube Lithonia fluoresecent fixtures joined end-to-end resulted in
stripping the screw threads in the sheet steel fixture. Is it acceptable to
substitute the next larger size of self-tapping machine screw. Of course it
won't be green and will be cadmium or zinc plated.

Alternatively, a longer ground might be screwed through a nut on the
backside of the fixture but this would be inconvenient.

David Merrill


Hi,
Of course.

On Jul 24, 11:09 pm, "David Merrill" wrote:
Attempting to connect two #14 ground wires to a single ground screw in
single-tube Lithonia fluoresecent fixtures joined end-to-end resulted in
stripping the screw threads in the sheet steel fixture. Is it acceptable to
substitute the next larger size of self-tapping machine screw. Of course it
won't be green and will be cadmium or zinc plated.

Alternatively, a longer ground might be screwed through a nut on the
backside of the fixture but this would be inconvenient.

Either one. The bare copper wires are indication enough that it's a
ground.

R

On Jul 24, 8:09 pm, "David Merrill" wrote:
Attempting to connect two #14 ground wires to a single ground screw in
single-tube Lithonia fluoresecent fixtures joined end-to-end resulted in
stripping the screw threads in the sheet steel fixture. Is it acceptable to
substitute the next larger size of self-tapping machine screw. Of course it
won't be green and will be cadmium or zinc plated.

Alternatively, a longer ground might be screwed through a nut on the
backside of the fixture but this would be inconvenient.

David Merrill

Maybe. No requirement for it to green. There is a prohibition on the
use of sheet metal screws for grounding and bonding. There is also a
variety of opinions on whether a self tapping screw is the same as a
sheet metal screw. The way the code is written it could be
interpreted that any screw other then a "sheet metal screw" would be
acceptable (i.e. drywall screw, wood screw, etc.) I am not sure that
was the intent.

2005 NEC

250.8 Termination of Grounding and Bonding Conductors
Equipment grounding conductors, grounding electrode conductors, and
bonding jumpers must be terminated by exothermic welding, listed
pressure connectors (set screw, compression), listed clamps, or other
listed fitting. Sheet-metal screws shall not be used for the
termination of grounding conductors.
Note: If a screw is used for grounding that screw shall not be used
for any other purpose.

In article Gjzpi.4507$fJ5.1780@pd7urf1no, Tony Hwang wrote:
David Merrill wrote:
Attempting to connect two #14 ground wires to a single ground screw in
single-tube Lithonia fluoresecent fixtures joined end-to-end resulted in
stripping the screw threads in the sheet steel fixture. Is it acceptable to
substitute the next larger size of self-tapping machine screw. Of course it
won't be green and will be cadmium or zinc plated.

Alternatively, a longer ground might be screwed through a nut on the
backside of the fixture but this would be inconvenient.

David Merrill


Hi,
Of course.

You mean, of course NOT. Two wires under one screw is a Code violation except
where the terminals are specifically listed for multiple wires.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

In article o9zpi.38980$Fc.28951@attbi_s21, "David Merrill" wrote:
Attempting to connect two #14 ground wires to a single ground screw in
single-tube Lithonia fluoresecent fixtures joined end-to-end resulted in
stripping the screw threads in the sheet steel fixture. Is it acceptable to
substitute the next larger size of self-tapping machine screw. Of course it
won't be green and will be cadmium or zinc plated.

Next size up is acceptable. It doesn't have to be green.

However -- the unacceptable part here is trying to put two wires under one
screw. Code prohibits connecting multiple wires to a single terminal unless
the terminal is specifically approved for multiple wires -- and you just
discovered one of the reasons why.

So for this one, and to avoid similar problems on other fixtures in the
future, loop a short (6" or so) pigtail around the grounding screw, and
wire-nut it to the two #14 ground wires.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

Exactly the information I needed. Thank you all.

David Merrill


"Doug Miller" wrote in message
t...
In article o9zpi.38980$Fc.28951@attbi_s21, "David Merrill"
wrote:
Attempting to connect two #14 ground wires to a single ground screw in
single-tube Lithonia fluoresecent fixtures joined end-to-end resulted in
stripping the screw threads in the sheet steel fixture. Is it acceptable
to
substitute the next larger size of self-tapping machine screw. Of course
it
won't be green and will be cadmium or zinc plated.

Next size up is acceptable. It doesn't have to be green.

However -- the unacceptable part here is trying to put two wires under one
screw. Code prohibits connecting multiple wires to a single terminal
unless
the terminal is specifically approved for multiple wires -- and you just
discovered one of the reasons why.

So for this one, and to avoid similar problems on other fixtures in the
future, loop a short (6" or so) pigtail around the grounding screw, and
wire-nut it to the two #14 ground wires.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.