Bill wrote:
On 12/6/2010 10:50 AM, Bill wrote:
Someone suggested (I could not locate the post) that if I wanted
quiet fluorescent lights, then I should look for those with an "A"
rating. Putting that detail aside temporarily. What would be the
practical
differences between a "standard electronic ballast with 20 THD"
and an "instant on electronic ballast with 10 THD"?

Bill

Trying, usually, to answer questions for myself before and after I
post, I ran across the following tidbit. It isn't that helpful
though. BTW, I have no reason to believe THD is accumulated if
fixtures are wired in a series, but I would certainly be interested
in knowing if anything of that nature is true.


THD stands for Total Harmonic Distortion. The distortion is feedback
caused by deviation from the sinusoidal waveform. The industry
standard is less than 20%. If the THD is very high (around 150%), an
electrical fire can occur. Magnetic ballast run 90%-120% THD.

The information above was copied from :
http://www.ace-ballast.com/articles/...last_Questions

Bill

Interesting stuff Bill. Though - I doubt I'll worry much about THD on the
next flourescent light I purchase.

--

-Mike-

On 12/6/2010 11:01 AM, Bill wrote:
On 12/6/2010 10:50 AM, Bill wrote:
Someone suggested (I could not locate the post) that if I wanted quiet
fluorescent lights, then I should look for those with an "A" rating.

Putting that detail aside temporarily. What would be the practical
differences between a "standard electronic ballast with 20% THD"
and an "instant on electronic ballast with 10% THD"?

Bill

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.

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?

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.

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

Bill

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-

On 12/6/2010 2:09 PM, Mike Marlow wrote:
Bill wrote:
On 12/6/2010 10:50 AM, Bill wrote:
Someone suggested (I could not locate the post) that if I wanted
quiet fluorescent lights, then I should look for those with an "A"
rating. Putting that detail aside temporarily. What would be the
practical
differences between a "standard electronic ballast with 20 THD"
and an "instant on electronic ballast with 10 THD"?

Bill

Trying, usually, to answer questions for myself before and after I
post, I ran across the following tidbit. It isn't that helpful
though. BTW, I have no reason to believe THD is accumulated if
fixtures are wired in a series, but I would certainly be interested
in knowing if anything of that nature is true.


THD stands for Total Harmonic Distortion. The distortion is feedback
caused by deviation from the sinusoidal waveform. The industry
standard is less than 20%. If the THD is very high (around 150%), an
electrical fire can occur. Magnetic ballast run 90%-120% THD.

The information above was copied from :
http://www.ace-ballast.com/articles/...last_Questions

Bill

Interesting stuff Bill. Though - I doubt I'll worry much about THD on the
next flourescent light I purchase.

You'll probably save $14 too! I'm considering purchasing about 15--and
I want 'em quiet! : )

When I built my last computer, I used a fanless graphics card and tossed
in an extra $100 for a quiet (decent quality) power supply. No hard
drives either--SSD. Maybe having quiet is a lot like having a sharp
Brad point drill... : )

Bill

Bill wrote:


You'll probably save $14 too! I'm considering purchasing about
15--and I want 'em quiet! : )

When I built my last computer, I used a fanless graphics card and
tossed in an extra $100 for a quiet (decent quality) power supply. No hard
drives either--SSD. Maybe having quiet is a lot like having
a sharp Brad point drill... : )


I put the cheapest 4 foot fixtures Home Depot sold in my garage - 15 of
them. At the time, those $8 fixtures used a -10 degree C ballast. I
figured 14 degrees F was good enough for me since my garage never gets that
cold. They are dead quiet. Can't tell you what the THD is on them - don't
really care. They were cheap, work well and are quiet. Unfortunately, Home
Depot's cheapest now is $9 and change, and it does not use a low temp
ballast like that. Can't remember what they are now, but it seems to me
they might be something like 50 degrees F.

--

-Mike-

On Mon, 06 Dec 2010 14:26:03 -0500, Bill
wrote:

On 12/6/2010 11:01 AM, Bill wrote:
On 12/6/2010 10:50 AM, Bill wrote:

No comment. gd&r



Someone suggested (I could not locate the post) that if I wanted quiet
fluorescent lights, then I should look for those with an "A" rating.

Putting that detail aside temporarily. What would be the practical
differences between a "standard electronic ballast with 20% THD"
and an "instant on electronic ballast with 10% THD"?

My first guess would be price.


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.

But is it cost-effective? Some people are downright proud of their
simple fluor lamp fixtures, asking several hundred dollars for the
same quality you get in a $50 fixture. Downright Festerful, and
sellin' that name!


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.

Bzzzzzzzzzzzzzzzzzt! E R R O R !


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?

Residential fixtures are wired in parallel, not series, Bill.
_Always_.

--
You can't wait for inspiration. You have to go after it with a club.
--Jack London

Bill writes:
On 12/6/2010 11:01 AM, Bill wrote:
On 12/6/2010 10:50 AM, Bill wrote:
Someone suggested (I could not locate the post) that if I wanted quiet
fluorescent lights, then I should look for those with an "A" rating.

Putting that detail aside temporarily. What would be the practical
differences between a "standard electronic ballast with 20% THD"
and an "instant on electronic ballast with 10% THD"?

Bill

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.

Why would you ever wire them in series? Each ballast needs to be
connected to the next in parallel when they're on the same circuit.

Some two-lamp ballasts (usually older magnetic) will wire the lamps
in series, and losing a single lamp (bulb) may cause the other bulb
to not light. This is generally not a problem with electronic ballasts.


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)

There is no such thing a "12-3 THHN".

The ballast in each fixture must be wired in parallel with respect
to all other ballasts on the same circuit the same way one wires multiple
incandescent fixtures on the same circuit.

----black------------+----------------+----------------+
| | |
ballast1 ballast2 ballast3
| | |
----white------------+----------------+----------------+

scott

Mike Marlow wrote:

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.


Thank you for working your way through my previous post. I know I still
haven't mastered the jargon. "Switched" seems like an unlikely term for
what I think of as a "split". Hopefully we're talking about the same
thing. I've been saving "switching" for those things they put on the
walls!

To avoid "cycling the breakers", Lew advised running 12-3 from two 20
Amp breakers (it would not have occurred to me to do that).

I'm thinking of this lighting as a 4 by 4 grid (or so), with rows 4' apart:

L1 L2 L1 L2
L2 L1 L2 L1
L1 L2 L1 L2
L2 L1 L2 L1.

The 2 hots each split at the beginning of row 1, going down row 1 and
also to the beginning to row 2, similarly for common and ground, etc.

Intuitively, I'd use 12-3 romex to the first box in the attic, exiting
the box with 12-3 THHN for row 1 and row2 into the interior of the
garage. The longer I think about it, the more connections I want to
stuff into a junction box (but I have to consider the box capacity of
course).

It seems like a natural "4 (juntion) box" problem. I'm not yet sure
where to locate the other junction boxes after the first. I've
definitely made some progress in understanding this! 16 fixtures wired
in parallel Without a wad of wires! Cool! Beautiful even! : )

Bill

"Bill" wrote

You'll probably save $14 too! I'm considering purchasing about 15--and I
want 'em quiet! : )

When I built my last computer, I used a fanless graphics card and tossed
in an extra $100 for a quiet (decent quality) power supply. No hard
drives either--SSD. Maybe having quiet is a lot like having a sharp Brad
point drill... : )

You should have it so rough.

I could never hear the quiet you mention.

I have ringing in my ears so loud that a cell phone ringing is hard to hear
over my ear's ringing.

Take care of your hearing, out there. This crap is no fun.
--
Jim in NC

Larry Jaques wrote:

snip


Residential fixtures are wired in parallel, not series, Bill.
_Always_.


Not when my old neighbor wires them. Lights where in series, swith was
parallel. He wondered why the circuit breaker tripped each time he
turned the switch on.

--
Jack Novak
Buffalo, NY - USA

Scott Lurndal wrote:

There is no such thing a "12-3 THHN".


Someone else wrote "pull 12-3 w/ground THHN". Is that more acceptable
(I understood what he was trying to tell me--2 hots, a common and a ground)?



The ballast in each fixture must be wired in parallel with respect
to all other ballasts on the same circuit the same way one wires multiple
incandescent fixtures on the same circuit.

----black------------+----------------+----------------+
| | |
ballast1 ballast2 ballast3
| | |
----white------------+----------------+----------------+

scott

I think I could wire that using 2 wire connectors each connecting 4
wires, grounds extra. The picture is helpful. Thank you.

Bill

In article ,
says...

On 12/6/2010 11:01 AM, Bill wrote:
On 12/6/2010 10:50 AM, Bill wrote:
Someone suggested (I could not locate the post) that if I wanted quiet
fluorescent lights, then I should look for those with an "A" rating.

Putting that detail aside temporarily. What would be the practical
differences between a "standard electronic ballast with 20% THD"
and an "instant on electronic ballast with 10% THD"?

Bill

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.

They're 110 v fixtures--that means that each one needs 110v. Wiring
them in series won't do that--they have to be in parallel.

As for a ballast failure, if the ballast failure trips the breaker they
all go out, if it doesn't then they shouldn't unless you hit some kind
of patholigical case.

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?

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.

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

That would be the way to do it if you want to be able to kill the power
to one set and still have the other available.

J. Clarke wrote:

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

That would be the way to do it if you want to be able to kill the power
to one set and still have the other available.

Yep, two light levels. The bigger the blade the more light I need.

Bill

On Mon, 06 Dec 2010 19:54:28 -0500, Nova wrote:

Larry Jaques wrote:

snip


Residential fixtures are wired in parallel, not series, Bill.
_Always_.


Not when my old neighbor wires them. Lights where in series, swith was
parallel. He wondered why the circuit breaker tripped each time he
turned the switch on.

Pardon me. Let me correct the deficiency in my post, Yack.

"WORKING/USABLE residential fixtures are wired in parallel, not
series, Bill. _Always_."

Better, oui?

--
You can't wait for inspiration. You have to go after it with a club.
--Jack London

On Mon, 06 Dec 2010 20:06:44 -0500, Bill wrote:

Scott Lurndal wrote:

There is no such thing a "12-3 THHN".

Right, it's 12ga THNN. One white (neutral) one black (hot), one bare
(ground). 3 separate wires, if you're inside a wiremold run, for each
lighting circuit. One piece of romex (for each circuit) if you're
between top floor and ceiling.


Someone else wrote "pull 12-3 w/ground THHN". Is that more acceptable
(I understood what he was trying to tell me--2 hots, a common and a ground)?

4 separate wires if you're breaking out from the wiremold into the two
circuits.


The ballast in each fixture must be wired in parallel with respect
to all other ballasts on the same circuit the same way one wires multiple
incandescent fixtures on the same circuit.

----black------------+----------------+----------------+
| | |
ballast1 ballast2 ballast3
| | |
----white------------+----------------+----------------+

scott

I think I could wire that using 2 wire connectors each connecting 4
wires, grounds extra. The picture is helpful. Thank you.

Haven't you bought a home wiring book yet, Bill? If not, do so.
If so, try reading it, eh?

--
You can't wait for inspiration. You have to go after it with a club.
--Jack London

Bill writes:

To avoid "cycling the breakers", Lew advised running 12-3 from two 20
Amp breakers (it would not have occurred to me to do that).

I'm not sure what this means, but if you're running two 120v circuits
using 12-3 from a pair of 20A breakers, make sure the breaker handles
are tied together such that both trip if either one trips.

scott

Bill writes:
Scott Lurndal wrote:

There is no such thing a "12-3 THHN".


Someone else wrote "pull 12-3 w/ground THHN". Is that more acceptable
(I understood what he was trying to tell me--2 hots, a common and a ground)?


When wire is referred to with a hyphen (e.g. 12-3), that means that there are
three AWG12 conductors encased in an outer jacket. Typically, such cables
are type "NM" (non-metallic sheathed) or "UF" (underground feeder). w/G adds
a non-jacketed conductor in the outer jacket that is designated the grounding
conductor. Most XX-3 w/g cables include red, black, white and unjacketed
conductors.

THHN is a wire "type" code used for single conductors that are routed typically
through some form of chase (electrometallic tubing (EMT) or nonmetallic tubing,
wiremold raceway, etc.).

THHN may not be used without an enclosing raceway of some form (note that if
your light fixtures are mounted end-to-end and there is a nipple or length of
EMT connecting them, then the fixtures themselves become a raceway and THHN is allowed
from the head fixture through the rest in the row).

scott

Scott Lurndal wrote:
writes:

To avoid "cycling the breakers", Lew advised running 12-3 from two 20
Amp breakers (it would not have occurred to me to do that).

I'm not sure what this means, but if you're running two 120v circuits
using 12-3 from a pair of 20A breakers, make sure the breaker handles
are tied together such that both trip if either one trips.

scott

Because???

On 07 Dec 2010 03:36:02 GMT, (Scott Lurndal)
wrote:

Bill writes:
Scott Lurndal wrote:

There is no such thing a "12-3 THHN".


Someone else wrote "pull 12-3 w/ground THHN". Is that more acceptable
(I understood what he was trying to tell me--2 hots, a common and a ground)?


When wire is referred to with a hyphen (e.g. 12-3), that means that there are
three AWG12 conductors encased in an outer jacket. Typically, such cables
are type "NM" (non-metallic sheathed) or "UF" (underground feeder). w/G adds
a non-jacketed conductor in the outer jacket that is designated the grounding
conductor. Most XX-3 w/g cables include red, black, white and unjacketed
conductors.

THHN is a wire "type" code used for single conductors that are routed typically
through some form of chase (electrometallic tubing (EMT) or nonmetallic tubing,
wiremold raceway, etc.).

THHN may not be used without an enclosing raceway of some form (note that if
your light fixtures are mounted end-to-end and there is a nipple or length of
EMT connecting them, then the fixtures themselves become a raceway and THHN is allowed
from the head fixture through the rest in the row).

scott
And thhn in a raceway on a "split" circuit (2 breakers tied together -
both sides of the service - 230 line to line) requires SEPARATE
NEUTRALS for each circuit, while NMD for the same application shares
the neutral. At least that was the requirement when we rewired the
new office.

On 07 Dec 2010 03:26:49 GMT, (Scott Lurndal)
wrote:

Bill writes:

To avoid "cycling the breakers", Lew advised running 12-3 from two 20
Amp breakers (it would not have occurred to me to do that).

I'm not sure what this means, but if you're running two 120v circuits
using 12-3 from a pair of 20A breakers, make sure the breaker handles
are tied together such that both trip if either one trips.

NO! He wants two separate circuits for different rows of lights. If
one blows, your way would have him in complete darkness instantly.

--
You can't wait for inspiration. You have to go after it with a club.
--Jack London

Larry Jaques wrote:

Haven't you bought a home wiring book yet, Bill? If not, do so.
If so, try reading it, eh?

Will do.

Bill wrote:
Scott Lurndal wrote:

There is no such thing a "12-3 THHN".


Someone else wrote "pull 12-3 w/ground THHN". Is that more acceptable
(I understood what he was trying to tell me--2 hots, a common and a
ground)?

That person simply mispoke - or does not understand. THHN is pulled as
individual wires.


--

-Mike-

wrote:
On 07 Dec 2010 03:36:02 GMT, (Scott Lurndal)
wrote:

writes:
Scott Lurndal wrote:

There is no such thing a "12-3 THHN".


Someone else wrote "pull 12-3 w/ground THHN". Is that more acceptable
(I understood what he was trying to tell me--2 hots, a common and a ground)?


When wire is referred to with a hyphen (e.g. 12-3), that means that there are
three AWG12 conductors encased in an outer jacket. Typically, such cables
are type "NM" (non-metallic sheathed) or "UF" (underground feeder). w/G adds
a non-jacketed conductor in the outer jacket that is designated the grounding
conductor. Most XX-3 w/g cables include red, black, white and unjacketed
conductors.

THHN is a wire "type" code used for single conductors that are routed typically
through some form of chase (electrometallic tubing (EMT) or nonmetallic tubing,
wiremold raceway, etc.).

THHN may not be used without an enclosing raceway of some form (note that if
your light fixtures are mounted end-to-end and there is a nipple or length of
EMT connecting them, then the fixtures themselves become a raceway and THHN is allowed
from the head fixture through the rest in the row).

scott
And thhn in a raceway on a "split" circuit (2 breakers tied together -
both sides of the service - 230 line to line) requires SEPARATE
NEUTRALS for each circuit, while NMD for the same application shares
the neutral. At least that was the requirement when we rewired the
new office.

Evidently for safety. You're less likely to find NMD on an office wall?

JustGuessing,
Bill

Mike Marlow wrote:
Bill wrote:
Scott Lurndal wrote:

There is no such thing a "12-3 THHN".


Someone else wrote "pull 12-3 w/ground THHN". Is that more acceptable
(I understood what he was trying to tell me--2 hots, a common and a
ground)?

That person simply mispoke - or does not understand. THHN is pulled as
individual wires.



No, he understands just fine (and we're going to pitz him oft again if
we're not careful)!
He has caused me to consider installing a shop pole and swapping out one
of the lights on the outside of my garage shop for one of red or cherry!

Bill

"Bill" wrote in message
...
Scott Lurndal wrote:
writes:

To avoid "cycling the breakers", Lew advised running 12-3 from two 20
Amp breakers (it would not have occurred to me to do that).

I'm not sure what this means, but if you're running two 120v circuits
using 12-3 from a pair of 20A breakers, make sure the breaker handles
are tied together such that both trip if either one trips.

scott

Because???

You do not want to have the possibility that one circuit has faulted and
the other still is hot in the same enclosure. You could still have a hot
circuit in there, when you think that it does not have juice to it. By
connecting both together, if one trips, you are assured that they both have
been shut off, and limit the possibility of getting a hold of a hot wire or
hot energized light switch or light.
--
Jim in NC

On Mon, 06 Dec 2010 23:17:59 -0500, Bill wrote:

Larry Jaques wrote:

Haven't you bought a home wiring book yet, Bill? If not, do so.
If so, try reading it, eh?

Will do.

Which? HAR!

--
You can't wait for inspiration. You have to go after it with a club.
--Jack London

Larry Jaques wrote:
On Mon, 06 Dec 2010 23:17:59 -0500, wrote:

Larry Jaques wrote:

Haven't you bought a home wiring book yet, Bill? If not, do so.
If so, try reading it, eh?

Will do.

Which? HAR!

Besides Stanley's book, which hasn't served me well in the past, I have
a Better Home & Gardens, "Step-By-Step BASIC WIRING published in 1980,
and a book I picked up this summer at Menard Inc: Step by Step Guide
Book, Home Wiring (which has 50 pages of wiring diagrams).
Unfortunately, I think most of the questions I have or will have concern
the physical aspects rather than the logical aspects.

Spent much of last evening reading about conduit (EMT). Spent too much
time reading fluorescent light fixture specs... I can recite long
cryptic model numbers from memory! : ) About the same as shopping for
components for a computer.

Bill

Lew Hodgett wrote:

BTW, in the future, if you want to work on your lighting system,
either learn how to trouble shoot it hot or hire an electrician.

Lew

With 15 or 16 fixtures wired in parallel circuits it seems the most
likely thing to malfunction is a fixture. Armed with a design schematic
and a voltometer, I know how to test for the presence or absence of
current. It's a pretty open system--compared to an automobile
transmission, for example. Where does your concern lie?

Regards,
Bill

Lew Hodgett wrote:

Run #12 AWG, THHN wire from switches to fixtures as previously
described.

Grab a beer and enjoy looking at you new lighting system and the
$1,000 it took to get it done.

If you come in a few bucks under $1K, buy some brad point drills.



You think maybe we should scale it back some? I was starting to get
concerned what it could cost for the heating and air-conditioning to
keep the paint-strippers satisfied! (Don't tell SWHMBO I said that).

I'll have to sleep on it. My BS is still in the box, my DP is on order,
and I don't have a TS. Not only that, some of my most creative interests
lie in luthery rather than cabinet making, so I'm not positive I need so
much ambient lighting (still there's a point to be made in not doing
things "half way"..). My point is that what I affectionately refer to
as my "shop" is not very advanced at this point in time--though it's
electrical wiring puts it and I a mile ahead of where it and I were at
the same time last year.

You provided me with the most focused approach though, and I appreciate
your advice, so I printed out your suggestions. As you know, I have a
workbench or two to build too, and a birdhouse and some handplanes to
make. And a math problem to solve too (a real stumper! ). It's
freezing outside tonight...good weather for design!

$200 or $1000--it's "just a "car repair". As you know, one of the most
valuable things is time... The "dreaming" though, that we all do I
think, is one of the closest things to being a kid at Christmas time.
The dreaming gets us through the trials and tribulations, no?

Ho, Ho, Ho (was heard outside the stipple-ceiling'ed hore-house)!
And to all a good nite! : )

Bill

In article , Bill
wrote:
I'll have to sleep on it. My BS is still in the box, my DP is on order,
and I don't have a TS. Not only that, some of my most creative interests
lie in luthery rather than cabinet making, so I'm not positive I need so
much ambient lighting

Well, you may not need as much light over the whole shop, but you'll
want a lot of bench lighting (easy to come by) for all the fiddly work
that instruments require. I was amused with your comment in another post
regarding "the bigger the blade, the more light I need" - I find it
works the other way, actually; though the light may not need to be all
over the shop for what you are doing with little blades.

--
Cats, coffee, chocolate...vices to live by

In article ,
says...

"Bill" wrote in message
...
Scott Lurndal wrote:
writes:

To avoid "cycling the breakers", Lew advised running 12-3 from two 20
Amp breakers (it would not have occurred to me to do that).

I'm not sure what this means, but if you're running two 120v circuits
using 12-3 from a pair of 20A breakers, make sure the breaker handles
are tied together such that both trip if either one trips.

scott

Because???

You do not want to have the possibility that one circuit has faulted and
the other still is hot in the same enclosure. You could still have a hot
circuit in there, when you think that it does not have juice to it. By
connecting both together, if one trips, you are assured that they both have
been shut off, and limit the possibility of getting a hold of a hot wire or
hot energized light switch or light.

Somehow or other I missed that that was being proposed. Agreed
wholeheartedly. If you're going to have two circuits going into the
same fixture you need to have one trip kill all power in that fixture.

Larry Jaques wrote:
On Mon, 06 Dec 2010 19:54:28 -0500, Nova wrote:


Larry Jaques wrote:

snip

Residential fixtures are wired in parallel, not series, Bill.
_Always_.


Not when my old neighbor wires them. Lights where in series, swith was
parallel. He wondered why the circuit breaker tripped each time he
turned the switch on.


Pardon me. Let me correct the deficiency in my post, Yack.

"WORKING/USABLE residential fixtures are wired in parallel, not
series, Bill. _Always_."

Better, oui?

--
You can't wait for inspiration. You have to go after it with a club.
--Jack London

Much better. ;-)

--
Jack Novak
Buffalo, NY - USA

Morgans wrote:


"Bill" wrote in message
...

Scott Lurndal wrote:

writes:

To avoid "cycling the breakers", Lew advised running 12-3 from two 20
Amp breakers (it would not have occurred to me to do that).


I'm not sure what this means, but if you're running two 120v circuits
using 12-3 from a pair of 20A breakers, make sure the breaker handles
are tied together such that both trip if either one trips.

scott


Because???


You do not want to have the possibility that one circuit has faulted
and the other still is hot in the same enclosure. You could still have
a hot circuit in there, when you think that it does not have juice to
it. By connecting both together, if one trips, you are assured that
they both have been shut off, and limit the possibility of getting a
hold of a hot wire or hot energized light switch or light.

The wiring arrangment using 12/3 for two feeds is called an "Edison
Circuit". Because the two circuits share a common neutral there is a
good chance that when one breaker trips the outlet/device affected can
still have a live neutral, being back fed through a device plugged into
the non-tripped circuit. This is the reason the two breakers should
trip together. I know my local code requires it and I think it's
specified by the NEC.

See:

http://www.phy.ornl.gov/divops/ESH/98-2.html

--
Jack Novak
Buffalo, NY - USA

On 12/7/2010 10:05 AM, Nova wrote:
Morgans wrote:


"Bill" wrote in message
...

Scott Lurndal wrote:

writes:

To avoid "cycling the breakers", Lew advised running 12-3 from two 20
Amp breakers (it would not have occurred to me to do that).


I'm not sure what this means, but if you're running two 120v circuits
using 12-3 from a pair of 20A breakers, make sure the breaker handles
are tied together such that both trip if either one trips.

scott


Because???


You do not want to have the possibility that one circuit has faulted
and the other still is hot in the same enclosure. You could still have
a hot circuit in there, when you think that it does not have juice to
it. By connecting both together, if one trips, you are assured that
they both have been shut off, and limit the possibility of getting a
hold of a hot wire or hot energized light switch or light.

The wiring arrangment using 12/3 for two feeds is called an "Edison
Circuit". Because the two circuits share a common neutral there is a
good chance that when one breaker trips the outlet/device affected can
still have a live neutral, being back fed through a device plugged into
the non-tripped circuit. This is the reason the two breakers should trip
together. I know my local code requires it and I think it's specified by
the NEC.

See:

http://www.phy.ornl.gov/divops/ESH/98-2.html


Thanks for the link. It leads one to think (and that's usually good!).

Bill

Bill wrote in :


Yep, two light levels. The bigger the blade the more light I need.

Bill


You'll find this is a "V" shaped curve... The smaller the blade, the more
light you'll need as well.

Puckdropper
--
Never teach your apprentice everything you know.

On 12/7/2010 10:05 AM, Nova wrote:

The wiring arrangment using 12/3 for two feeds is called an "Edison
Circuit". Because the two circuits share a common neutral there is a
good chance that when one breaker trips the outlet/device affected can
still have a live neutral, being back fed through a device plugged into
the non-tripped circuit. This is the reason the two breakers should trip
together. I know my local code requires it and I think it's specified by
the NEC.

See:

http://www.phy.ornl.gov/divops/ESH/98-2.html


Then what's keeping all of the "live neutrals" from any of the other
circuits in the panel from raising their evil heads at any time? -- The
Ground (!), right? So, IF the former circuits are well-grounded, then
it seems the "Edison's Circuit" issue will not be a problem. Of
course, that's a crucial, "IF". Correct???

Regards,
Bill

Bill wrote:
On 12/7/2010 10:05 AM, Nova wrote:

The wiring arrangment using 12/3 for two feeds is called an "Edison
Circuit". Because the two circuits share a common neutral there is a
good chance that when one breaker trips the outlet/device affected can
still have a live neutral, being back fed through a device plugged into
the non-tripped circuit. This is the reason the two breakers should trip
together. I know my local code requires it and I think it's specified by
the NEC.

See:

http://www.phy.ornl.gov/divops/ESH/98-2.html


Then what's keeping all of the "live neutrals" from any of the other
circuits in the panel from raising their evil heads at any time? -- The
Ground (!), right? So, IF the former circuits are well-grounded, then
it seems the "Edison's Circuit" issue will not be a problem. Of
course, that's a crucial, "IF". Correct???

Regards,
Bill

The problem arises is you break the neutral path abck to the box when
servicing an outlet or device. The neutral may be hot even though the
breaker for that branch has been switched off.

--
Jack Novak
Buffalo, NY - USA

In article ,
Scott Lurndal wrote:
When wire is referred to with a hyphen (e.g. 12-3), that means that
there are three AWG12 conductors encased in an outer jacket. Typically,
such cables are type "NM" (non-metallic sheathed) or "UF" (underground
feeder). w/G adds a non-jacketed conductor in the outer jacket that is
designated the grounding conductor. Most XX-3 w/g cables include red,
black, white and unjacketed conductors.

THHN is a wire "type" code used for single conductors that are routed
typically through some form of chase (electrometallic tubing (EMT) or
nonmetallic tubing, wiremold raceway, etc.).

THHN may not be used without an enclosing raceway of some form (note
that if your light fixtures are mounted end-to-end and there is a nipple
or length of EMT connecting them, then the fixtures themselves become a
raceway and THHN is allowed from the head fixture through the rest in
the row).

Thanks for the clarification. Sitting here in the UK I'd been wondering
what all your american abbreviations meant :-)

--
Stuart Winsor

Midland RISC OS show - Sat July 9th 2011

On 12/7/2010 12:33 PM, Nova wrote:
Bill wrote:
On 12/7/2010 10:05 AM, Nova wrote:

The wiring arrangment using 12/3 for two feeds is called an "Edison
Circuit". Because the two circuits share a common neutral there is a
good chance that when one breaker trips the outlet/device affected can
still have a live neutral, being back fed through a device plugged into
the non-tripped circuit. This is the reason the two breakers should trip
together. I know my local code requires it and I think it's specified by
the NEC.

See:

http://www.phy.ornl.gov/divops/ESH/98-2.html


Then what's keeping all of the "live neutrals" from any of the other
circuits in the panel from raising their evil heads at any time? --
The Ground (!), right? So, IF the former circuits are well-grounded,
then it seems the "Edison's Circuit" issue will not be a problem. Of
course, that's a crucial, "IF". Correct???

Regards,
Bill

The problem arises is you break the neutral path abck to the box when
servicing an outlet or device. The neutral may be hot even though the
breaker for that branch has been switched off.

Thank you, I get it. It seems like an extra wire is a small price to
pay to avoid this dilemma! And, if I ever get electrocuted, at least I
might be able to figure out Why! If I got electrocuted and couldn't
figure out why it would Pi$s me off! ; )

Bill

On Mon, 06 Dec 2010 23:02:40 -0500, Bill wrote:

Scott Lurndal wrote:
writes:

To avoid "cycling the breakers", Lew advised running 12-3 from two 20
Amp breakers (it would not have occurred to me to do that).

I'm not sure what this means, but if you're running two 120v circuits
using 12-3 from a pair of 20A breakers, make sure the breaker handles
are tied together such that both trip if either one trips.

scott

Because???

Because 1) - it is code.
2) if one circuit trips and you assume the wire is "dead" you
could be - the black could be dead, and the red live, and a lifted
neutral (which is common to both) would be LIVE.