I have a home office in my spare bedroom. My overhead light fixture, which just uses one 60W light bulb, blew on Monday. I replaced the light bulb and used it yesterday while working. Late last night, I went into my office and when I turned on the light, the new bulb blew. I left it until this morning. It got me thinking on what could be causing two light bulbs to blow with 48 hours. It's either the switch or the fixture.

I went out and bought a new wall switch (20A Leviton)and installed it, and replaced the blown lightbulb. It's working now, but for how long, I don't know.

Has anyone had any experience where a bad light switch would cause light bulbs to blow only upon turn-on? Once the switch is turned on, it seems to work fine.
I'm an electronic technician by trade, so I understand power concepts, but I haven't heard of a switch causing a spike above the normal AC voltage.

BTW, I checked the line voltage at the lightbulb and its 115 Vac.

On Wednesday, July 10, 2013 9:29:54 AM UTC-7, rlz wrote:
I have a home office in my spare bedroom. My overhead light fixture, which just uses one 60W light bulb, blew on Monday. I replaced the light bulb and used it yesterday while working. Late last night, I went into my office and when I turned on the light, the new bulb blew. I left it until this morning. It got me thinking on what could be causing two light bulbs to blow with 48 hours. It's either the switch or the fixture.



I went out and bought a new wall switch (20A Leviton)and installed it, and replaced the blown lightbulb. It's working now, but for how long, I don't know.



Has anyone had any experience where a bad light switch would cause light bulbs to blow only upon turn-on? Once the switch is turned on, it seems to work fine.

I'm an electronic technician by trade, so I understand power concepts, but I haven't heard of a switch causing a spike above the normal AC voltage.



BTW, I checked the line voltage at the lightbulb and its 115 Vac.

It’s more likely that the problem with the light bulbs is lack of quality control in the manufacturing process. One my jobs is changing light bulbs and I have seen a wide variation in how long a light bulb lasts even though they come from the same package.

rlz writes:

I have a home office in my spare bedroom. My overhead light fixture,
which just uses one 60W light bulb, blew on Monday. I replaced the
light bulb and used it yesterday while working. Late last night, I
went into my office and when I turned on the light, the new bulb blew.
I left it until this morning. It got me thinking on what could be
causing two light bulbs to blow with 48 hours. It's either the switch
or the fixture.

I went out and bought a new wall switch (20A Leviton)and installed it,
and replaced the blown lightbulb. It's working now, but for how long,
I don't know.

Has anyone had any experience where a bad light switch would cause
light bulbs to blow only upon turn-on? Once the switch is turned on,
it seems to work fine.
I'm an electronic technician by trade, so I understand power concepts,
but I haven't heard of a switch causing a spike above the normal AC
voltage.

BTW, I checked the line voltage at the lightbulb and its 115 Vac.

Coincidence.

That's my guess.
I don't think it's that unusual for a brand new bulb to blow.
It was tested at the factory (at least according to How It's Made
on TV), but it's new, and it got shaken and moved around on it's way
from the factory to your home.

I don't see how any defect in the switch could cause a bulb to blow.
It's either going to pass current or not.

--
Dan Espen

I remember the day I blew two or three
Phillips in a row (lamp over the work bench
with grinder). Some other brand worked,
fine. This was about 1988, so can't remember
what was the other brand. Not that the QC
is same, so many years later.
..
Christopher A. Young
Learn more about Jesus
www.lds.org
..
..
wrote in message ...

It’s more likely that the problem with the light bulbs is lack of quality control in the manufacturing process. One my jobs is changing light bulbs and I have seen a wide variation in how long a light bulb lasts even though they come from the same package.

On 07/10/2013 12:38 PM, Dan Espen wrote:
rlz writes:

I have a home office in my spare bedroom. My overhead light fixture,
which just uses one 60W light bulb, blew on Monday. I replaced the
light bulb and used it yesterday while working. Late last night, I
went into my office and when I turned on the light, the new bulb blew.
I left it until this morning. It got me thinking on what could be
causing two light bulbs to blow with 48 hours. It's either the switch
or the fixture.

I went out and bought a new wall switch (20A Leviton)and installed it,
and replaced the blown lightbulb. It's working now, but for how long,
I don't know.

Has anyone had any experience where a bad light switch would cause
light bulbs to blow only upon turn-on? Once the switch is turned on,
it seems to work fine.
I'm an electronic technician by trade, so I understand power concepts,
but I haven't heard of a switch causing a spike above the normal AC
voltage.

BTW, I checked the line voltage at the lightbulb and its 115 Vac.

Coincidence.

That's my guess.
I don't think it's that unusual for a brand new bulb to blow.
It was tested at the factory (at least according to How It's Made
on TV), but it's new, and it got shaken and moved around on it's way
from the factory to your home.

I don't see how any defect in the switch could cause a bulb to blow.
It's either going to pass current or not.


Agreed, I think it was just bad luck with the replacement bulb. The
light switch is simply a set of contacts. There's nothing in there that
can cause anything other than maybe a little arcing, worst case, but a
good quality light switch shouldn't arc significantly with only a 60W load.

An incandescent bulb failing on turn on is a fairly common failure mode.
The resistance of the filament increases dramatically with temperature,
meaning that the current drawn on a "cold start" is much higher than
normal for a brief period until the filament warms up (which happens in
a fraction of a second.)

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

+1 for the defective bulbs.

I've been in these DIY forums for a long time and it's common for people to buy a package of light bulbs and find that an unusually high number of them burn out in an unusually short period of time.

And, just like you, they presume the problem has to be in the house wiring somewhere.

On Wednesday, July 10, 2013 10:29:54 AM UTC-6, rlz wrote:
I have a home office in my spare bedroom. My overhead light fixture, which just uses one 60W light bulb, blew on Monday. I replaced the light bulb and used it yesterday while working. Late last night, I went into my office and when I turned on the light, the new bulb blew. I left it until this morning. It got me thinking on what could be causing two light bulbs to blow with 48 hours. It's either the switch or the fixture. I went out and bought a new wall switch (20A Leviton)and installed it, and replaced the blown lightbulb. It's working now, but for how long, I don't know. Has anyone had any experience where a bad light switch would cause light bulbs to blow only upon turn-on? Once the switch is turned on, it seems to work fine. I'm an electronic technician by trade, so I understand power concepts, but I haven't heard of a switch causing a spike above the normal AC voltage. BTW, I checked the line voltage at the lightbulb and its 115 Vac.

Thanks everyone for the post. I'm suspecting the light bulbs as well, but the previous owner of this house did shoddy work in the wiring as far as I can tell. When I replaced the switch this morning, I found both ground wires (live & load) physically attached to the grounding screw. So I disassembled them, crimped them together while adding a pigtail to attach to the switch. I didn't think this was allowed having two ground wires on one grounding screw.

I also went back and looked at the package of lightbulbs. I think they were a cheap brand to start off with.

Robin

On 07/10/2013 04:31 PM, rlz wrote:
On Wednesday, July 10, 2013 10:29:54 AM UTC-6, rlz wrote:
I have a home office in my spare bedroom. My overhead light
fixture, which just uses one 60W light bulb, blew on Monday. I
replaced the light bulb and used it yesterday while working. Late
last night, I went into my office and when I turned on the light,
the new bulb blew. I left it until this morning. It got me thinking
on what could be causing two light bulbs to blow with 48 hours.
It's either the switch or the fixture. I went out and bought a new
wall switch (20A Leviton)and installed it, and replaced the blown
lightbulb. It's working now, but for how long, I don't know. Has
anyone had any experience where a bad light switch would cause
light bulbs to blow only upon turn-on? Once the switch is turned
on, it seems to work fine. I'm an electronic technician by trade,
so I understand power concepts, but I haven't heard of a switch
causing a spike above the normal AC voltage. BTW, I checked the
line voltage at the lightbulb and its 115 Vac.

Thanks everyone for the post. I'm suspecting the light bulbs as
well, but the previous owner of this house did shoddy work in the
wiring as far as I can tell. When I replaced the switch this
morning, I found both ground wires (live & load) physically attached
to the grounding screw. So I disassembled them, crimped them
together while adding a pigtail to attach to the switch. I didn't
think this was allowed having two ground wires on one grounding
screw.

It's not. There are screw connections ("backwire") which allow two
wires to go under one screw, but I have never seen a ground screw that
was anything other than the standard loop the wire under it type.

If this is a metal box, that should also be grounded.

Typically to save space in a situation like that, I will loop one ground
wire under the ground screw for the box and leave a couple inches free;
then do the same thing with the other wire under the screw on the
switch/receptacle, then splice the two together with a yellow wire nut.
That way I don't have a bunch of pigtails in the box unnecessarily
taking up space. This is assuming, of course, that the installer left
enough length on the wires for you to do this.


I also went back and looked at the package of lightbulbs. I think
they were a cheap brand to start off with.

That's possible too, although I have to say I expect the quality of
incandescent bulbs to start dropping if it hasn't already as they are
starting to be phased out. I just hope that good high-CRI LED bulbs are
available and inexpensive by the time that we can't get incandescents at
all anymore. I liked the Philips L-prize bulb but sadly it's been
already discontinued - I did managed to snag a couple from HD while they
were $15 though.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

In article ,
rlz wrote:

I'm an electronic technician by trade, so I understand power concepts, but I
haven't heard of a switch causing a spike above the normal AC voltage.

Robin-

Chances are you had a defective light bulb, as others noted.

If you burn out more bulbs, one other cause could be a loose neutral
connection in your power hookup. When that happens, a load imbalance
between the two 120 VAC sides of the 240 VAC feed, will result in a high
voltage on the side with less load, and low voltage on the side with
greater load. (I assume you are in the U.S.)

It is possible for the neutral wire to have an open or high resistance
connection at either the power company's transformer, or at your
electrical meter.

Fred

On 7/10/2013 2:19 PM, nestork wrote:
+1 for the defective bulbs.

I've been in these DIY forums for a long time and it's common for people
to buy a package of light bulbs and find that an unusually high number
of them burn out in an unusually short period of time.

And, just like you, they presume the problem has to be in the house
wiring somewhere.


Hello, AC Service Company.

Uh yea, I'm Dillard Dumbass at 1402 Defected Lane and I'm having trouble
with my air conditioner.

What seems to be the problem sir?

It's not cooling, I think it needs a new thermostat.........

TDD

What a dufas. Not cooling means low on freon.
..
Christopher A. Young
Learn more about Jesus
www.lds.org
..
..
"The Daring Dufas" wrote in message ...

Hello, AC Service Company.

Uh yea, I'm Dillard Dumbass at 1402 Defected Lane and I'm having trouble
with my air conditioner.

What seems to be the problem sir?

It's not cooling, I think it needs a new thermostat.........

TDD

On 7/10/2013 6:39 PM, Stormin Mormon wrote:
What a dufas. Not cooling means low on freon.
.

No Silly Stormy, "Dufas" is a proper surname, "doofus" is the idiot
designation. o_O

TDD

On 07/10/2013 08:16 PM, The Daring Dufas wrote:
On 7/10/2013 6:39 PM, Stormin Mormon wrote:
What a dufas. Not cooling means low on freon.
.

No Silly Stormy, "Dufas" is a proper surname, "doofus" is the idiot
designation. o_O

TDD


"The Count of Monty Crisco by Alexandry Dumbass..."


--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Wed, 10 Jul 2013 16:53:09 -0400, Nate Nagel
wrote:

On 07/10/2013 04:31 PM, rlz wrote:
On Wednesday, July 10, 2013 10:29:54 AM UTC-6, rlz wrote:
I have a home office in my spare bedroom. My overhead light
fixture, which just uses one 60W light bulb, blew on Monday. I
replaced the light bulb and used it yesterday while working. Late
last night, I went into my office and when I turned on the light,
the new bulb blew. I left it until this morning. It got me thinking
on what could be causing two light bulbs to blow with 48 hours.
It's either the switch or the fixture. I went out and bought a new
wall switch (20A Leviton)and installed it, and replaced the blown
lightbulb. It's working now, but for how long, I don't know. Has
anyone had any experience where a bad light switch would cause
light bulbs to blow only upon turn-on? Once the switch is turned
on, it seems to work fine. I'm an electronic technician by trade,
so I understand power concepts, but I haven't heard of a switch
causing a spike above the normal AC voltage. BTW, I checked the
line voltage at the lightbulb and its 115 Vac.

Thanks everyone for the post. I'm suspecting the light bulbs as
well, but the previous owner of this house did shoddy work in the
wiring as far as I can tell. When I replaced the switch this
morning, I found both ground wires (live & load) physically attached
to the grounding screw. So I disassembled them, crimped them
together while adding a pigtail to attach to the switch. I didn't
think this was allowed having two ground wires on one grounding
screw.

It's not. There are screw connections ("backwire") which allow two
wires to go under one screw, but I have never seen a ground screw that
was anything other than the standard loop the wire under it type.

If this is a metal box, that should also be grounded.

If it is a metal box and the box is grounded the ground screw is
redundant unless it is an isolated ground outlet.

Typically to save space in a situation like that, I will loop one ground
wire under the ground screw for the box and leave a couple inches free;
then do the same thing with the other wire under the screw on the
switch/receptacle, then splice the two together with a yellow wire nut.
That way I don't have a bunch of pigtails in the box unnecessarily
taking up space. This is assuming, of course, that the installer left
enough length on the wires for you to do this.


I also went back and looked at the package of lightbulbs. I think
they were a cheap brand to start off with.

That's possible too, although I have to say I expect the quality of
incandescent bulbs to start dropping if it hasn't already as they are
starting to be phased out. I just hope that good high-CRI LED bulbs are
available and inexpensive by the time that we can't get incandescents at
all anymore. I liked the Philips L-prize bulb but sadly it's been
already discontinued - I did managed to snag a couple from HD while they
were $15 though.

nate

On Wed, 10 Jul 2013 19:39:44 -0400, "Stormin Mormon"
wrote:

What a dufas. Not cooling means low on freon.
.
Christopher A. Young
Learn more about Jesus
www.lds.org
.
.
"The Daring Dufas" wrote in message ...

Hello, AC Service Company.

Uh yea, I'm Dillard Dumbass at 1402 Defected Lane and I'm having trouble
with my air conditioner.

What seems to be the problem sir?

It's not cooling, I think it needs a new thermostat.........

TDD


Or a blown fuse, or a plugged up condenser, or a bad wire somewhere -
- - -

On Wed, 10 Jul 2013 09:29:54 -0700 (PDT), rlz
wrote:

I have a home office in my spare bedroom. My overhead light fixture, which just uses one 60W light bulb, blew on Monday.

Use a desk lamp. Problem solved.

I hate overhead lighting in an office. At home I have a desk lamp
with a four tube florescent type of bulb. At work, only in the early
morning of winter do I turn a light on. I get enough light from the
two windows.

You have my curiosity. Two ground wires, live and load? Tell me some more about that.
..
Christopher A. Young
Learn more about Jesus
www.lds.org
..
..
"rlz" wrote in message ...

I'm an electronic technician by trade, so I understand power concepts,


Thanks everyone for the post.

When I replaced the switch this morning, I found both ground wires (live & load) physically attached to the grounding screw. So I disassembled them, crimped them together while adding a pigtail to attach to the switch. I didn't think this was allowed having two ground wires on one grounding screw.

Robin

Sorry, I think I've made that misteak once befo.
..
Christopher A. Young
Learn more about Jesus
www.lds.org
..
..
"The Daring Dufas" wrote in message ...
On 7/10/2013 6:39 PM, Stormin Mormon wrote:
What a dufas. Not cooling means low on freon.
.

No Silly Stormy, "Dufas" is a proper surname, "doofus" is the idiot
designation. o_O

TDD

If you had my customer base, or TDD's customer
base, you'd understand the signifigance. It's an in
house joke.
..
Christopher A. Young
Learn more about Jesus
www.lds.org
..
..
wrote in message ...
On Wed, 10 Jul 2013 19:39:44 -0400, "Stormin Mormon"
wrote:

Not cooling means low on freon.
.
Christopher A. Young

Or a blown fuse, or a plugged up condenser, or a bad wire somewhere -

I also vote for just bad luck with a defective bulb.

I've never seen a switch cause failure and can't really picture how it would work.

High voltage could, maybe, but I've never run into that either.

What I have seen quite a bit is the center contact in the socket bent down too low. Then people end up screwing the lightbulb in too hard trying to make contact. That can damage the base of the bulb.

You may need to bend that contact out, gently, with the power off, and with a nonconductive tool like a popsickle stick. Then turn the power on, screw the lamp in until it lights, and go 1/8th turn more. Not 1/4, not 1/2. 1/8 is correct.

"Nate Nagel" wrote in message
...
On 07/10/2013 12:38 PM, Dan Espen wrote:
rlz writes:

I have a home office in my spare bedroom. My overhead light fixture,
which just uses one 60W light bulb, blew on Monday. I replaced the
light bulb and used it yesterday while working. Late last night, I
went into my office and when I turned on the light, the new bulb blew.
I left it until this morning. It got me thinking on what could be
causing two light bulbs to blow with 48 hours. It's either the switch
or the fixture.

I went out and bought a new wall switch (20A Leviton)and installed it,
and replaced the blown lightbulb. It's working now, but for how long,
I don't know.

Has anyone had any experience where a bad light switch would cause
light bulbs to blow only upon turn-on? Once the switch is turned on,
it seems to work fine.





I'm an electronic technician by trade, so I understand power concepts,
but I haven't heard of a switch causing a spike above the normal AC
voltage.

BTW, I checked the line voltage at the lightbulb and its 115 Vac.

Coincidence.

That's my guess.
I don't think it's that unusual for a brand new bulb to blow.
It was tested at the factory (at least according to How It's Made
on TV), but it's new, and it got shaken and moved around on it's way
from the factory to your home.

I don't see how any defect in the switch could cause a bulb to blow.
It's either going to pass current or not.


Agreed, I think it was just bad luck with the replacement bulb. The light
switch is simply a set of contacts. There's nothing in there that can
cause anything other than maybe a little arcing, worst case, but a good
quality light switch shouldn't arc significantly with only a 60W load.

An incandescent bulb failing on turn on is a fairly common failure mode.
The resistance of the filament increases dramatically with temperature,
meaning that the current drawn on a "cold start" is much higher than
normal for a brief period until the filament warms up (which happens in a
fraction of a second.)

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Also agree. No matter how good the quality control in the factory, a bulb
can get a stress crack during shippling, handling or even sitting on a
shelf. The crack will let air into the bulb and than the filament will burn
out. Sometimes that happens quickly; or, it may take a while. You can tell
an "air leaker" by looking at the burned-out bulb. It will look cloudy or
smoky inside.

Tomsic

On 7/11/2013 8:22 AM, TimR wrote:
I also vote for just bad luck with a defective bulb.

I've never seen a switch cause failure and can't really picture how
it would work.

High voltage could, maybe, but I've never run into that either.

What I have seen quite a bit is the center contact in the socket bent
down too low. Then people end up screwing the lightbulb in too hard
trying to make contact. That can damage the base of the bulb.

You may need to bend that contact out, gently, with the power off,
and with a nonconductive tool like a popsickle stick. Then turn the
power on, screw the lamp in until it lights, and go 1/8th turn more.
Not 1/4, not 1/2. 1/8 is correct.


The OP didn't write what type of light he has. A light switch that's
arcing can blow a CFL but not necessarily an incandescent light. ^_^

TDD

On 7/10/2013 7:55 PM, wrote:
On Wed, 10 Jul 2013 16:53:09 -0400, Nate
wrote:
On 07/10/2013 04:31 PM, rlz wrote:

Thanks everyone for the post. I'm suspecting the light bulbs as
well, but the previous owner of this house did shoddy work in the
wiring as far as I can tell. When I replaced the switch this
morning, I found both ground wires (live& load) physically attached
to the grounding screw. So I disassembled them, crimped them
together while adding a pigtail to attach to the switch. I didn't
think this was allowed having two ground wires on one grounding
screw.

It's not. There are screw connections ("backwire") which allow two
wires to go under one screw, but I have never seen a ground screw that
was anything other than the standard loop the wire under it type.

If this is a metal box, that should also be grounded.

If it is a metal box and the box is grounded the ground screw is
redundant unless it is an isolated ground outlet.

In the US switches can be grounded through the mounting screws to a
metal box. That is not true for receptacles unless they are "self
grounding" or are on some surface mount boxes.

From the OP's description, my guess is he has a plastic switch box.

On 07/11/2013 07:19 AM, Stormin Mormon wrote:
You have my curiosity. Two ground wires, live and load? Tell me some
more about that. . Christopher A. Young Learn more about Jesus
www.lds.org . . "rlz" wrote in message
...

I'm an electronic technician by trade, so I understand power
concepts,


Thanks everyone for the post.

When I replaced the switch this morning, I found both ground wires
(live & load) physically attached to the grounding screw. So I
disassembled them, crimped them together while adding a pigtail to
attach to the switch. I didn't think this was allowed having two
ground wires on one grounding screw.

Robin


I'm assuming that he's using "live" for "line" and he's referring to the
cables not individual conductors, e.g. "live" enters the box from the
breaker panel and "load" is the cable from the switch box to the fixture
box. Not common terminology but at least I thought I understood where
he was going with that.

If I'm wrong, Robin, please clarify...

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On 07/11/2013 09:22 AM, TimR wrote:
I also vote for just bad luck with a defective bulb.

I've never seen a switch cause failure and can't really picture how
it would work.

High voltage could, maybe, but I've never run into that either.

What I have seen quite a bit is the center contact in the socket bent
down too low. Then people end up screwing the lightbulb in too hard
trying to make contact. That can damage the base of the bulb.

You may need to bend that contact out, gently, with the power off,
and with a nonconductive tool like a popsickle stick. Then turn the
power on, screw the lamp in until it lights, and go 1/8th turn more.
Not 1/4, not 1/2. 1/8 is correct.


And if it is a seldom replaced bulb, put some nose grease on the
threads. Srsly.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

May I add my two séance to all? Replacing the switch should not have any
effect on burning of bulb out. Ground wire adding pig tail to making
convenient for hook up to switch or receptacle I do not know of any rules
that covers that as long is firmly secure to the ground. Remember some
houses are wire in with Romax and some with BX . With Romax carries isolated
green or bare cooper wire with in cable itself. The BX is metal cover and it
carries also ground wire but it is bare because it is option of use If all
junction boxes are metal, one does not need ground wire because all
connection/junction are metal to metal, however if it is Romax one most use
ground wire at all the time. Switches fuses, circuit barker most always be
on hot side, in some area you can find that some people or ass holes put
switches and fuses/circuit breaker on neutral side, on older system one
always most checks or you can get yourself in trouble. Also at no time use
neutral as ground or ground as neutral, this could cause big problems with
GFI circuits, beside that ground should never carry any current at no time.
Well that is what I got to say.


"Stormin Mormon" wrote in message
...
You have my curiosity. Two ground wires, live and load? Tell me some more
about that.
..
Christopher A. Young
Learn more about Jesus
www.lds.org
..
..
"rlz" wrote in message
...

I'm an electronic technician by trade, so I understand power concepts,


Thanks everyone for the post.

When I replaced the switch this morning, I found both ground wires (live &
load) physically attached to the grounding screw. So I disassembled them,
crimped them together while adding a pigtail to attach to the switch. I
didn't think this was allowed having two ground wires on one grounding
screw.

Robin

On Thursday, July 11, 2013 9:50:21 AM UTC-6, Nate Nagel wrote:
On 07/11/2013 07:19 AM, Stormin Mormon wrote: You have my curiosity. Two ground wires, live and load? Tell me some more about that. . Christopher A. Young Learn more about Jesus www.lds.org . . "rlz" wrote in message ... I'm an electronic technician by trade, so I understand power concepts, Thanks everyone for the post. When I replaced the switch this morning, I found both ground wires (live & load) physically attached to the grounding screw. So I disassembled them, crimped them together while adding a pigtail to attach to the switch. I didn't think this was allowed having two ground wires on one grounding screw. Robin I'm assuming that he's using "live" for "line" and he's referring to the cables not individual conductors, e.g. "live" enters the box from the breaker panel and "load" is the cable from the switch box to the fixture box. Not common terminology but at least I thought I understood where he was going with that. If I'm wrong, Robin, please clarify... nate -- replace "roosters" with "cox" to reply. http://members.cox.net/njnagel

That is correct. There are two cables coming into the plastic box. The run from the breaker and the one going up to the ceiling light fixture. Both of these cables each have a ground wire. Both ground wires were secured to the grounding screw on the switch. Sorry for the wrong terminology. I thought "live" and load" was betther than "this one" and "that one"...LOL

On Thu, 11 Jul 2013 07:19:05 -0400, "Stormin Mormon"
wrote:

You have my curiosity. Two ground wires, live and load? Tell me some more about that.
.
Christopher A. Young
Learn more about Jesus
www.lds.org
.
.
"rlz" wrote in message ...

I'm an electronic technician by trade, so I understand power concepts,


Thanks everyone for the post.

When I replaced the switch this morning, I found both ground wires (live & load) physically attached to the grounding screw. So I disassembled them, crimped them together while adding a pigtail to attach to the switch. I didn't think this was allowed having two ground wires on one grounding screw.

Robin
I SUSPECT he means ground on the feed side and the load side of the
circuit in a circuit with the neutrals tied together and the power
switched. Now, if the ground screw in question is the ground screw on
the utility box the switch is mounted in, 2 bares under one screw is
acceptable - and if the box is a metal box the switch does NOT need to
be grounded (at least here in Ontario)

On Thu, 11 Jul 2013 09:26:51 -0400, "Tomsic" wrote:


"Nate Nagel" wrote in message
...
On 07/10/2013 12:38 PM, Dan Espen wrote:
rlz writes:

I have a home office in my spare bedroom. My overhead light fixture,
which just uses one 60W light bulb, blew on Monday. I replaced the
light bulb and used it yesterday while working. Late last night, I
went into my office and when I turned on the light, the new bulb blew.
I left it until this morning. It got me thinking on what could be
causing two light bulbs to blow with 48 hours. It's either the switch
or the fixture.

I went out and bought a new wall switch (20A Leviton)and installed it,
and replaced the blown lightbulb. It's working now, but for how long,
I don't know.

Has anyone had any experience where a bad light switch would cause
light bulbs to blow only upon turn-on? Once the switch is turned on,
it seems to work fine.





I'm an electronic technician by trade, so I understand power concepts,
but I haven't heard of a switch causing a spike above the normal AC
voltage.

BTW, I checked the line voltage at the lightbulb and its 115 Vac.

Coincidence.

That's my guess.
I don't think it's that unusual for a brand new bulb to blow.
It was tested at the factory (at least according to How It's Made
on TV), but it's new, and it got shaken and moved around on it's way
from the factory to your home.

I don't see how any defect in the switch could cause a bulb to blow.
It's either going to pass current or not.


Agreed, I think it was just bad luck with the replacement bulb. The light
switch is simply a set of contacts. There's nothing in there that can
cause anything other than maybe a little arcing, worst case, but a good
quality light switch shouldn't arc significantly with only a 60W load.

An incandescent bulb failing on turn on is a fairly common failure mode.
The resistance of the filament increases dramatically with temperature,
meaning that the current drawn on a "cold start" is much higher than
normal for a brief period until the filament warms up (which happens in a
fraction of a second.)

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

Also agree. No matter how good the quality control in the factory, a bulb
can get a stress crack during shippling, handling or even sitting on a
shelf. The crack will let air into the bulb and than the filament will burn
out. Sometimes that happens quickly; or, it may take a while. You can tell
an "air leaker" by looking at the burned-out bulb. It will look cloudy or
smoky inside.

Tomsic

The quality od incandescent bulbs available in North America has taken
a very STEEP nose-dive over the last number of years. Even "brand
name" bulbs are likely to be Chinese made - with the implied lack of
quality control - and a good percentage of "brand name" bulbs (and
other commodities) are counterfeit - which usually means even lower
quality and less quality control.

Somehow, doesn't sound right, to have a live ground, and a load ground. Neither should be energized, unless something is wrong. Perhaps some electrician on the list can remind us what those two grounds should be called.
..
Christopher A. Young
Learn more about Jesus
www.lds.org
..
..
"rlz" wrote in message ...
I'm an electronic technician by trade, so I understand power concepts, Thanks everyone for the post. When I replaced the switch this morning, I found both ground wires (live & load) physically attached to the grounding screw. So I disassembled them, crimped them together while adding a pigtail to attach to the switch.

I'm assuming that he's using "live" for "line" and he's referring to the cables not individual conductors, e.g. "live" enters the box from the breaker panel and "load" is the cable from the switch box to the fixture box. Not common terminology but at least I thought I understood where he was going with that. If I'm wrong, Robin, please clarify... nate --


That is correct. There are two cables coming into the plastic box. The run from the breaker and the one going up to the ceiling light fixture. Both of these cables each have a ground wire. Both ground wires were secured to the grounding screw on the switch. Sorry for the wrong terminology. I thought "live" and load" was betther than "this one" and "that one"...LOL

We could say that the quality really blows?
..
Christopher A. Young
Learn more about Jesus
www.lds.org
..
..
wrote in message
...

The quality od incandescent bulbs available in North America has taken
a very STEEP nose-dive over the last number of years. Even "brand
name" bulbs are likely to be Chinese made - with the implied lack of
quality control - and a good percentage of "brand name" bulbs (and
other commodities) are counterfeit - which usually means even lower
quality and less quality control.