On Sun, 25 Dec 2016 22:16:28 -0600, Mark Lloyd
wrote:

On 12/25/2016 03:26 PM, James Wilkinson Sword wrote:

[snip]


Hearing a 50Hz mains hum isn't that bad, but imagine hearing a higher
frequency.


Once I had a TV where the horizontal frequency (almost 16KHz) was
audible. It was unpleasant to be around for very long. IIRC, I sold it
to someone with hearing loss who couldn't hear it.
It was not uncommon for one of the coils on the fly-back transformer
to come loose amd "sing". Ised to drive a wooden toorhpick between the
offending coil snd the core, or wedge a popsicle stich between the
twoo coils to shut them up. Sometimes a glob of that nasty red HV dope
tribbled down the toothpock or globbed between the goils worked too.

On Mon, 26 Dec 2016 03:56:12 -0000, wrote:

On Sun, 25 Dec 2016 21:41:54 -0000, "James Wilkinson Sword"
wrote:

On Sun, 25 Dec 2016 03:40:55 -0000, wrote:

On Sun, 25 Dec 2016 02:12:52 -0000, "James Wilkinson Sword"
wrote:


In the UK we figured out how to put lights on the ceiling.

We have decorators here who think things like that are so "dated". No
matter what people have, they want something different.

I prefer things to be out of my way and work automatically.

I am OK with that but I don't want a big "We have ways to make you
talk" light in the ceiling. I like my walking around light to be more
diffuse.

I have all the rooms bright, and the bedroom dimmer so it's not dazzling when I wake up.

--
Football is a bunch of millionaires ruining a lawn -- Charlie Brooker

On Mon, 26 Dec 2016 04:03:44 -0000, Mark Lloyd wrote:

On 12/25/2016 12:05 PM, James Wilkinson Sword wrote:

[snip]

This is typical of the positions where the wires go in a UK single
lightswitch. If it's not part of a two way system (switch at each end
of a hall),

Called 3-way in the US. I think I understand why, but 2-way sounds more
reasonable.

It can be 3-way (or more) if you want, you add a switch in the middle that swaps the poles. But if there's two switches, calling it 3-way is illogical.

one wire goes into the top hole, and the other into either
bottom hole. In fact you can change which way is on by which bottom
hole you use. If you pay attention to "TOP" and "FOR SP 1 WAY USE L2",
the the switch will be down for on.

Using the same switch for one-switch and two-switch installations,
making it easier to solve the wrong-orientation problem. The switches
would be more expensive that way.

I think you can get single pole switches, but since they're only a couple of £ each, most places just stock the doubles.

--
Where Article 51 applies, the number of Directors subject to retirement by
rotation under Article 49 shall be reduced (subject to Article 64(g)) by
the same number as that by which the number of Directors has fallen below
that fixed under Article 44.
(Proposed change to the constitution of Mensa)

On Mon, 26 Dec 2016 04:08:32 -0000, wrote:

On Sun, 25 Dec 2016 21:45:23 -0000, "James Wilkinson Sword"
wrote:

Monitoring for software updates for one. It is still in there chugging
along, about like your PC when it is setting on the desk top and no
applications active.

My PC can use 400 watts more when thinking hard than when on and idling.

I am sure the processor in a smart TV is the same way.

Depends on the design. Our Sky satellite TV boxes use the same on or standby.

--
Tower: "Delta 351, you have traffic at 10 o'clock, 6 miles!"
Delta 351: "Give us another hint! We have digital watches!"

On Mon, 26 Dec 2016 14:42:11 -0000, trader_4 wrote:

On Sunday, December 25, 2016 at 12:59:22 PM UTC-5, Tony944 wrote:


€œCan I change€� duplex outlet that one half
works of the switch and other being

directly on the line:: €œNO€� unless you can run additional line, you
need

four wires 2 Hot one Neutral and one for Ground, Only then you
can split

the duplex, one output hook to hot line and one hook on the line
coming from

the switch. This is for 120 Voltage source USA standard
Receptacle.


That's wrong. If the source hot is already in the receptacle box then the
conversion

is fairly simple. You only need to run another wire if the source hot is in
the switch

box.


***No you are wrong "Look what man is asking
for"



DerbyDad, as usual, is 100% right. He answered the OP's question correctly
and even supplied the diagrams. If the OP has a receptacle where it's
wired with the power source going to the receptacle first, then to the
switch, then no additional wire needs to be run. The diagram showed
exactly that. It's only if the power goes to the switch first that an
additional wire is needed. Around here at least, that is the most common
configuration. We don't know how it was wired in the OP's case, he
did not say., but given that the OP says he's got it done already,
I suspect he in fact didn't have to run a new cable, so it sounds like
he probably had a hot at the receptacle.

So much less wiring when the switch is on the socket.

--
Abdicate (v.), to give up all hope of ever having a flat stomach.

On Mon, 26 Dec 2016 15:00:53 -0000, trader_4 wrote:

On Friday, December 23, 2016 at 7:53:40 PM UTC-5, wrote:
On Sat, 24 Dec 2016 00:22:53 -0000, "James Wilkinson Sword"
wrote:

It sounds like the same rule there. The light on the ceiling is a
"luminaire" but you can also just have a receptacle on that switch.
(for a lamp) Ceiling lights were out of fashion here for a while so
the code was amended. Now everyone wants a fan with a light in it so
the code had to upgrade those ceiling boxes to handle a 50 pound fan.

There shouldn't be a code. Do what you want in your own house, or there is no freedom. You guys built America so you were the land of the free, then you let your government dictate to you how you operate your own ****ing lights!

--

I agree but it is what it is.
If it makes you feel better, the code really only affects builders.
Once you move in you will never see an inspector again if you never
get a permit for anything.
I seldom do and when I do I get to the place where they will sign off
the permit as fast as I can and then do what I want.
I believe in the intent of the code, safety, but I am willing to avoid
some of the BS if it is not dangerous.

Plus most people are not spec'ing out there own house and having it built.
So, you'd be stuck with whatever the builder decided to do, whatever corners
they cut to save a buck, etc. And there would be even more variation in
what you wind up with from home to home. All in all, I think code is a
good idea, including the new reqt to have a neutral at all switch locations.

Making convenience a law is insanity.

How many people have been in here over the years with problems trying to
use a smart switch like X10 at a switch where there is no neutral? How
many man hours have been wasted finding out that they can't work with
an LED, CFL, etc? All that is solved with a neutral there and it's no
big deal to run when you're installing a new circuit.


--
Police arrested two kids yesterday, one was drinking battery acid, and the other was eating fireworks. They charged one and let the other one off.

On Mon, 26 Dec 2016 14:22:02 -0000, FromTheRafters wrote:

Mark Lloyd explained on 12/25/2016 :
On 12/25/2016 03:26 PM, James Wilkinson Sword wrote:

[snip]


Hearing a 50Hz mains hum isn't that bad, but imagine hearing a higher
frequency.


Once I had a TV where the horizontal frequency (almost 16KHz) was audible. It
was unpleasant to be around for very long. IIRC, I sold it to someone with
hearing loss who couldn't hear it.

I could hear most of them.

What year?

I could also hear the detectors in stores
back when they were sonic. Not anymore though, and not because the
technology has changed, but because my hearing has changed.

Detectors?

--
The longest recorded flight of a chicken is thirteen seconds.

On Mon, 26 Dec 2016 18:00:06 -0000, "James Wilkinson Sword"
wrote:

All in all, I think code is a
good idea, including the new reqt to have a neutral at all switch locations.

Making convenience a law is insanity.

That convenience is what allows you to use PIR detectors on CFL and
LED lamps.
The old 'Power through the load" (2 wire) designs only work with an
incandescent or magnetic ballast load.

On Mon, 26 Dec 2016 18:40:40 -0000, wrote:

On Mon, 26 Dec 2016 18:00:06 -0000, "James Wilkinson Sword"
wrote:

All in all, I think code is a
good idea, including the new reqt to have a neutral at all switch locations.

Making convenience a law is insanity.

That convenience is what allows you to use PIR detectors on CFL and
LED lamps.
The old 'Power through the load" (2 wire) designs only work with an
incandescent or magnetic ballast load.

Not sure what you're referring to. Do you mean live and neutral to the switch versus live and switched live to the switch? Both designs have two wires plus earth to the switch. The only difference is whether the power runs under the floor or around the ceiling.

My house was built in 1979, and has no neutrals at the switches. But earth is a neutral :-)

--
Balderdash (n.), a rapidly receding hairline.

On Monday, December 26, 2016 at 1:48:41 PM UTC-5, James Wilkinson Sword wrote:
On Mon, 26 Dec 2016 18:40:40 -0000, wrote:

On Mon, 26 Dec 2016 18:00:06 -0000, "James Wilkinson Sword"
wrote:

All in all, I think code is a
good idea, including the new reqt to have a neutral at all switch locations.

Making convenience a law is insanity.

That convenience is what allows you to use PIR detectors on CFL and
LED lamps.
The old 'Power through the load" (2 wire) designs only work with an
incandescent or magnetic ballast load.

Not sure what you're referring to. Do you mean live and neutral to the switch versus live and switched live to the switch? Both designs have two wires plus earth to the switch. The only difference is whether the power runs under the floor or around the ceiling.

My house was built in 1979, and has no neutrals at the switches. But earth is a neutral :-)

--
Balderdash (n.), a rapidly receding hairline.

What he means is that anything more intelligent than a dumb switch needs
power and without a neutral at the switch, it's usually a problem. If you follow
this thread people are here all the time with an X10 switch, motion
detector switch, etc, that either need a neutral or a sufficient load
so that they can power themselves through the load. The latter works
with an incandescent, a heater, etc, but not with an LED, CFL, etc.

On Mon, 26 Dec 2016 10:54:18 -0800 (PST), trader_4
wrote:

On Monday, December 26, 2016 at 1:48:41 PM UTC-5, James Wilkinson Sword wrote:
On Mon, 26 Dec 2016 18:40:40 -0000, wrote:

On Mon, 26 Dec 2016 18:00:06 -0000, "James Wilkinson Sword"
wrote:

All in all, I think code is a
good idea, including the new reqt to have a neutral at all switch locations.

Making convenience a law is insanity.

That convenience is what allows you to use PIR detectors on CFL and
LED lamps.
The old 'Power through the load" (2 wire) designs only work with an
incandescent or magnetic ballast load.

Not sure what you're referring to. Do you mean live and neutral to the switch versus live and switched live to the switch? Both designs have two wires plus earth to the switch. The only difference is whether the power runs under the floor or around the ceiling.

My house was built in 1979, and has no neutrals at the switches. But earth is a neutral :-)

--
Balderdash (n.), a rapidly receding hairline.

What he means is that anything more intelligent than a dumb switch needs
power and without a neutral at the switch, it's usually a problem. If you follow
this thread people are here all the time with an X10 switch, motion
detector switch, etc, that either need a neutral or a sufficient load
so that they can power themselves through the load. The latter works
with an incandescent, a heater, etc, but not with an LED, CFL, etc.

He already said, he just uses the EGC if he needs a neutral.
Yikes

After serious thinking trader_4 wrote :
On Monday, December 26, 2016 at 10:41:22 AM UTC-5, FromTheRafters wrote:
trader_4 wrote on 12/26/2016 :
On Sunday, December 25, 2016 at 4:46:09 PM UTC-5, wrote:
On Sat, 24 Dec 2016 18:00:52 -0800 (PST), DerbyDad03
wrote:

Snip

If an EE knows how to wire a split switched receptacle, it is something
(s)he learned from a source unrelated to the degree they earned - unless
perhaps it was an elective.

I doubt you have an EE degree, but if you do, are you telling us that
where you got it, they had to instruct you on every single possible thing
you will ever see? Where I got my degree, they taught us to think like
an engineer, use electrical principles from Ohms Law to Maxwell's equations
and apply them to the real world. It takes nothing more than the most
basic understanding of electricity to be able to figure out how to wire
a split-receptacle, something I already knew before I entered high school,
let alone college. And no, no one had to specifically instruct me in how
it worked. I saw one, figured it out in maybe a minute.



It sure wasn't an elective at RIT back when I attended.

If you graduated from there, they should be embarrassed.

I disagree. When I first learned about electricity and Ohm's Law, my
instructor used the 'plumbing analogy' and mentioned that it is not
exactly correct but 'good enough for most electrical work'. If you
wanted to go into physics or electronics it has many failures.

Where does Ohms Law fail with regard to a switched outlet? It doesn't.
Neither do Kirchoff's Laws, which are all that's needed to understand
a simple switched circuit.



For one thing, current (measured in amps) does *not* flow through a
conductor even though almost all electrical people will insist that it
does. Current is the *rate* at which *charge* flows and the rate
doesn't *go* anywhere. The number of charge *carriers* (usually, but
not always electrons) past a certain point (or cross sectional area)
can be counted and multiplied by the amount of charge each carries, to
get the current.


A silly nit which has nothing to do with anything. Again, what does that
have to do with wiring a switched outlet?



Understanding Ohm's Law and/or Maxwell's equations may be a
prerequisite for your chosen profession, but that doesn't mean everyone
who knows them must also know how to wire household switches.

If you know them and really understand them, then there has to be
something wrong with you or how you were taught that you can have
a degree in EE and not be able to apply Ohms Law and the most
elementary of circuit principles to solve the problem of how a
switched outlet works. Good grief, has all of America gone dumb?
Some of you seem to think that the purpose of college and an EE degree
is to teach you how to do specific tasks. It's not. It's to teach
science, physics and engineering that you can then apply to all the
new things you encounter. That is what engineering is, the application
of science to actual, real world problems. What you are suggesting is
that colleges are there to train essentially robots, that can only deal
with that which they've explicitly been shown.




There are
other endeavors within the electricity fields than construction work.
You would be completely bamboozled by ECM gear and someone who learned
about it from the ground up (basic E & E) might assume, like you do,
that the things they learned apply to all other fields, but they don't.

I never said electricity, Ohms Law, Maxwell;s equations, etc apply to
anything other than electricity. The switched outlet here is a very
basic circuit that anyone who has an EE should be able to figure out.
It's irrelevant that the circuit is in a house.
And if you can't, then you or your educational system have failed.

Yet you still seem to think that Ohm's Law applies to open circuits.
What is the 'voltage drop' across the open contacts of such a switch?

On Mon, 26 Dec 2016 19:09:34 -0000, wrote:

On Mon, 26 Dec 2016 10:54:18 -0800 (PST), trader_4
wrote:

On Monday, December 26, 2016 at 1:48:41 PM UTC-5, James Wilkinson Sword wrote:
On Mon, 26 Dec 2016 18:40:40 -0000, wrote:

On Mon, 26 Dec 2016 18:00:06 -0000, "James Wilkinson Sword"
wrote:

All in all, I think code is a
good idea, including the new reqt to have a neutral at all switch locations.

Making convenience a law is insanity.

That convenience is what allows you to use PIR detectors on CFL and
LED lamps.
The old 'Power through the load" (2 wire) designs only work with an
incandescent or magnetic ballast load.

Not sure what you're referring to. Do you mean live and neutral to the switch versus live and switched live to the switch? Both designs have two wires plus earth to the switch. The only difference is whether the power runs under the floor or around the ceiling.

My house was built in 1979, and has no neutrals at the switches. But earth is a neutral :-)

--
Balderdash (n.), a rapidly receding hairline.

What he means is that anything more intelligent than a dumb switch needs
power and without a neutral at the switch, it's usually a problem. If you follow
this thread people are here all the time with an X10 switch, motion
detector switch, etc, that either need a neutral or a sufficient load
so that they can power themselves through the load. The latter works
with an incandescent, a heater, etc, but not with an LED, CFL, etc.

He already said, he just uses the EGC if he needs a neutral.
Yikes

Why not? It's the same once it leaves my house. Only two cores in the supply cable.

--
I know you believe you understand what you think I said,
but I'm not sure you realize that what you heard is not
what I meant.

On Mon, 26 Dec 2016 14:19:03 -0500, FromTheRafters
wrote:

What is the 'voltage drop' across the open contacts of such a switch?

The same as the max voltage supplied at the source.

On Mon, 26 Dec 2016 19:42:19 -0000, "James Wilkinson Sword"
wrote:

He already said, he just uses the EGC if he needs a neutral.
Yikes

Why not? It's the same once it leaves my house. Only two cores in the supply cable.

The problem is what happens on your side of the main bonding jumper.
If a fault develops in that EGC you are putting 230v on the case of
every piece of grounded equipment on that circuit.

On Mon, 26 Dec 2016 20:03:23 -0000, wrote:

On Mon, 26 Dec 2016 19:42:19 -0000, "James Wilkinson Sword"
wrote:

He already said, he just uses the EGC if he needs a neutral.
Yikes

Why not? It's the same once it leaves my house. Only two cores in the supply cable.

The problem is what happens on your side of the main bonding jumper.
If a fault develops in that EGC you are putting 230v on the case of
every piece of grounded equipment on that circuit.

Unlikely for that to happen, and in any case, they're very low current devices.

--
A guy bought his wife a beautiful diamond ring for Christmas.
A friend of his said, "I thought she wanted one of those sporty 4-Wheel drive vehicles."
"She did," he replied. "But where in the hell was I gonna find a fake Jeep?"

On Mon, 26 Dec 2016 20:23:58 -0000, "James Wilkinson Sword"
wrote:


The problem is what happens on your side of the main bonding jumper.
If a fault develops in that EGC you are putting 230v on the case of
every piece of grounded equipment on that circuit.

Unlikely for that to happen, and in any case, they're very low current devices.

Your house, your choice.
Get enough of them and you will be tripping the RCD tho, particularly
if you have some other incidental leakage.
It is a worse problem here since our GFCI trips at 5ma, not the 30 you
have but the GFCI only serves one circuit, not the whole house.

On Mon, 26 Dec 2016 20:42:16 -0000, wrote:

On Mon, 26 Dec 2016 20:23:58 -0000, "James Wilkinson Sword"
wrote:


The problem is what happens on your side of the main bonding jumper.
If a fault develops in that EGC you are putting 230v on the case of
every piece of grounded equipment on that circuit.

Unlikely for that to happen, and in any case, they're very low current devices.

Your house, your choice.

Low currents can't hurt you.

Get enough of them and you will be tripping the RCD tho, particularly
if you have some other incidental leakage.

I don't have an RCD and never will, they're a nuisance. I use fuses.

It is a worse problem here since our GFCI trips at 5ma, not the 30 you
have but the GFCI only serves one circuit, not the whole house.

Actually ours tend to be 30 for one circuit or 50 for the whole house.

--
My wife doesn't surf the net, she paddles.

posted for all of us...



On Sat, 24 Dec 2016 22:12:00 -0000, "James Wilkinson Sword"
wrote:


My cats like to walk in front of me then wonder why I trip over them. They seem to be clever enough not to try the same with cars.

Tripping over a 115 pound Labrador is a little more significant
because when he jumps up he will knock you over if you haven't already
fallen

Yeah, my wife fell over our late & great lab, orbital fracture and mucho
contusions. I read later that tripping over pets is in the ER room
statistics.

--
Tekkie

posted for all of us...



On Sat, 24 Dec 2016 22:09:00 -0000, "James Wilkinson Sword"
wrote:

They do want disconnects to be installed in a uniform way, just to
avoid confusion when someone may need to operate it in a hurry

You push it the way is isn't to turn it off, you don't have options. And I doubt most people would remember which way in a panic.

--
If your developed muscle memory is "off is down" you don't have to
think in an emergency

+50 he is making assumptions.

--
Tekkie

On Mon, 26 Dec 2016 20:58:14 -0000, Tekkie® wrote:

posted for all of us...



On Sat, 24 Dec 2016 22:12:00 -0000, "James Wilkinson Sword"
wrote:


My cats like to walk in front of me then wonder why I trip over them.. They seem to be clever enough not to try the same with cars.

Tripping over a 115 pound Labrador is a little more significant
because when he jumps up he will knock you over if you haven't already
fallen

Yeah, my wife fell over our late & great lab, orbital fracture and mucho
contusions. I read later that tripping over pets is in the ER room
statistics.

So are weird things like smashing your head on a toilet bowl.

--
What has four legs, is big, green, fuzzy, and if it fell out of a tree would kill you?
A pool table.

On Mon, 26 Dec 2016 21:19:05 -0000, Tekkie® wrote:

posted for all of us...



On Sat, 24 Dec 2016 22:09:00 -0000, "James Wilkinson Sword"
wrote:

They do want disconnects to be installed in a uniform way, just to
avoid confusion when someone may need to operate it in a hurry

You push it the way is isn't to turn it off, you don't have options. And I doubt most people would remember which way in a panic.

--
If your developed muscle memory is "off is down" you don't have to
think in an emergency

+50 he is making assumptions.

What?

--
I find it ironic that the colours red, white, and blue stand for freedom, until they're flashing behind you.

On 12/26/2016 12:01 PM, trader_4 wrote:
On Monday, December 26, 2016 at 10:41:22 AM UTC-5, FromTheRafters wrote:

Understanding Ohm's Law and/or Maxwell's equations may be a
prerequisite for your chosen profession, but that doesn't mean everyone
who knows them must also know how to wire household switches.
If you know them and really understand them, then there has to be
something wrong with you or how you were taught that you can have
a degree in EE and not be able to apply Ohms Law and the most
elementary of circuit principles to solve the problem of how a
switched outlet works. Good grief, has all of America gone dumb?
Some of you seem to think that the purpose of college and an EE degree
is to teach you how to do specific tasks. It's not. It's to teach
science, physics and engineering that you can then apply to all the
new things you encounter. That is what engineering is, the application
of science to actual, real world problems. What you are suggesting is
that colleges are there to train essentially robots, that can only deal
with that which they've explicitly been shown.

My neighbor is a EE. EEs are a special kind of stupid.

For example, two years ago a county snow plow knocked over about a dozen neighborhood mailboxes.
I replaced mine by pulling my old 4x4 post out with a bumper jack and dropping a new $5 post into the existing hole. Complete job took less than 30 minutes.

OTOH, EE neighbor bought a splint-style post repair kit from a big box store. The repaired post lasted about 6 months until a summer storm blew it over.
Next repair attempt was another post repair kit but this time he added some guy wires fastened to tent stakes.
As you might imagine, the tent stakes pulled out of the ground and the whole mess fell over again.

EE currently has added 3 concrete blocks to the tent stakes to keep them from pulling out of the ground. It seems to be holding at the moment. ;-)

In article , says...

On Mon, 26 Dec 2016 20:42:16 -0000, wrote:


Low currents can't hurt you.

Get enough of them and you will be tripping the RCD tho, particularly
if you have some other incidental leakage.

I don't have an RCD and never will, they're a nuisance. I use fuses.

It is a worse problem here since our GFCI trips at 5ma, not the 30 you
have but the GFCI only serves one circuit, not the whole house.

Actually ours tend to be 30 for one circuit or 50 for the whole house.


Depends on what you call low current.

As little as 10 ma can be painful, 20 ma sevear pain and maybe
difficulty breathing. At 50 ma you start to get to the danger zone.
Depending on the path of the current you may be able to take more or
less.

Even less than 10 ma is enough to make you hirt yourself.
Most people can feel around 1 to 2 ma.

On Mon, 26 Dec 2016 21:48:10 -0000, Ralph Mowery wrote:

In article , says...

On Mon, 26 Dec 2016 20:42:16 -0000, wrote:


Low currents can't hurt you.

Get enough of them and you will be tripping the RCD tho, particularly
if you have some other incidental leakage.

I don't have an RCD and never will, they're a nuisance. I use fuses.

It is a worse problem here since our GFCI trips at 5ma, not the 30 you
have but the GFCI only serves one circuit, not the whole house.

Actually ours tend to be 30 for one circuit or 50 for the whole house.


Depends on what you call low current.

As little as 10 ma can be painful, 20 ma sevear pain and maybe
difficulty breathing. At 50 ma you start to get to the danger zone.
Depending on the path of the current you may be able to take more or
less.

Even less than 10 ma is enough to make you hirt yourself.
Most people can feel around 1 to 2 ma.

Whatever you get by touching the live and neutral 240 volts directly doesn't bother me much. It gives me a fright, and I feel warmth if I don't let go immediately. That which goes through a little microchip won't be much at all.

--
Amanpreet was overheard at the hospital angrily say, "My wife just delivered twins!!!"
A passerby said, "So? You should be happy about that. Why are you so angry?"
"I want to know who the son of a bitch is that's the father of the second kid!"

On Mon, 26 Dec 2016 16:48:10 -0500, Ralph Mowery
wrote:

Depends on what you call low current.

As little as 10 ma can be painful, 20 ma sevear pain and maybe
difficulty breathing. At 50 ma you start to get to the danger zone.
Depending on the path of the current you may be able to take more or
less.

Even less than 10 ma is enough to make you hirt yourself.
Most people can feel around 1 to 2 ma.


We used to always say the 5ma GFCI will keep you from being
electrocuted but it doesn't keep you from falling off the ladder.

On Mon, 26 Dec 2016 22:12:19 -0000, wrote:

On Mon, 26 Dec 2016 16:48:10 -0500, Ralph Mowery
wrote:

Depends on what you call low current.

As little as 10 ma can be painful, 20 ma sevear pain and maybe
difficulty breathing. At 50 ma you start to get to the danger zone.
Depending on the path of the current you may be able to take more or
less.

Even less than 10 ma is enough to make you hirt yourself.
Most people can feel around 1 to 2 ma.


We used to always say the 5ma GFCI will keep you from being
electrocuted but it doesn't keep you from falling off the ladder.

And serves no purpose at all if you touch live and neutral, which is just as likely unless you have stuff earthed everywhere. I tend not to earth things, as all it does is increase the chance of shock.

--
An airliner was having engine trouble, and the pilot instructed the cabin crew to have the passengers take their seats and get prepared for an emergency landing.
A few minutes later, the pilot asked the flight attendants if everyone was buckled in and ready.
"All set back here, Captain," came the reply, "except one lawyer who is still going around passing out business cards."

On Monday, December 26, 2016 at 8:22:07 AM UTC-6, FromTheRafters wrote:
Mark Lloyd explained on 12/25/2016 :
On 12/25/2016 03:26 PM, James Wilkinson Sword wrote:

Hearing a 50Hz mains hum isn't that bad, but imagine hearing a higher
frequency.

Once I had a TV where the horizontal frequency (almost 16KHz) was audible. It
was unpleasant to be around for very long. IIRC, I sold it to someone with
hearing loss who couldn't hear it.

I could hear most of them. I could also hear the detectors in stores
back when they were sonic. Not anymore though, and not because the
technology has changed, but because my hearing has changed.


I'm over 60 and I can still hear a battery operated analogue wall clock ticking across the room when it's quiet enough. When I was working on CRT TV's, monitors and terminals, I could hear the horizontal oscillators. Back when ultrasonic motion detectors were common in the security industry, I could hear the harmonics from those things. I've always liked peace and quiet so I protected my hearing. When I went to a nightclub to repair some equipment, I wore hearing protection. I had the earmuffs and some of the in the ear hearing protectors which had a little disk valve inside that closed when there was loud sound. Those earplugs were pretty slick because I could hear someone talking on a construction site but when a worker dropped a pipe or cranked up a hammer drill next to us, the valve closed and blocked the loud sounds. The new ones are even better. I've had to tell nurses to lower their voice because I'm not deaf like most of the older folks at the center. My friend Stinky is 53 and quite hard of hearing because as a young man, he listened to Def Leppard at full volume on his full ear covering head phones.. ヽ(ヅ)ノ

[8~{} Uncle Earie Monster

On Monday, December 26, 2016 at 12:01:49 PM UTC-6, James Wilkinson Sword wrote:
On Mon, 26 Dec 2016 14:22:02 -0000, FromTheRafters wrote:

Mark Lloyd explained on 12/25/2016 :
On 12/25/2016 03:26 PM, James Wilkinson Sword wrote:

[snip]

Hearing a 50Hz mains hum isn't that bad, but imagine hearing a higher
frequency.

Once I had a TV where the horizontal frequency (almost 16KHz) was audible. It
was unpleasant to be around for very long. IIRC, I sold it to someone with
hearing loss who couldn't hear it.

I could hear most of them.

What year?

I could also hear the detectors in stores
back when they were sonic. Not anymore though, and not because the
technology has changed, but because my hearing has changed.

Detectors?
--


Back in the 1970's, ultrasonic motion detectors for security systems were quite common in businesses. The last of the old Polaroid instant cameras used an ultrasonic transducer to measure distance to the subject of a picture and focus the camera. There were some ultrasonic motion detectors at one time that detected a shopper in the isle at a retailer so an electronic advertising display could start playing music and the voice of a pitchman. I haven't seen one for a while but I could hear the harmonics and clicks. ヽ(€¢€¿€¢)ノ

[8~{} Uncle Bat Monster

On Mon, 26 Dec 2016 23:44:34 -0000, Uncle Monster wrote:

On Monday, December 26, 2016 at 12:01:49 PM UTC-6, James Wilkinson Sword wrote:
On Mon, 26 Dec 2016 14:22:02 -0000, FromTheRafters wrote:

Mark Lloyd explained on 12/25/2016 :
On 12/25/2016 03:26 PM, James Wilkinson Sword wrote:

[snip]

Hearing a 50Hz mains hum isn't that bad, but imagine hearing a higher
frequency.

Once I had a TV where the horizontal frequency (almost 16KHz) was audible. It
was unpleasant to be around for very long. IIRC, I sold it to someone with
hearing loss who couldn't hear it.

I could hear most of them.

What year?

I could also hear the detectors in stores
back when they were sonic. Not anymore though, and not because the
technology has changed, but because my hearing has changed.

Detectors?
--


Back in the 1970's, ultrasonic motion detectors for security systems were quite common in businesses. The last of the old Polaroid instant cameras used an ultrasonic transducer to measure distance to the subject of a picture and focus the camera. There were some ultrasonic motion detectors at one time that detected a shopper in the isle at a retailer so an electronic advertising display could start playing music and the voice of a pitchman. I haven't seen one for a while but I could hear the harmonics and clicks. ヽ(€¢€¿€¢)ノ

What I think's strange is motion detectors stay on when the alarm is deactivated. Why don't the PIRs only run at night?

--
Whenever I feel blue, I start breathing again.

On Mon, 26 Dec 2016 23:44:34 -0000, Uncle Monster wrote:

On Monday, December 26, 2016 at 12:01:49 PM UTC-6, James Wilkinson Sword wrote:
On Mon, 26 Dec 2016 14:22:02 -0000, FromTheRafters wrote:

Mark Lloyd explained on 12/25/2016 :
On 12/25/2016 03:26 PM, James Wilkinson Sword wrote:

[snip]

Hearing a 50Hz mains hum isn't that bad, but imagine hearing a higher
frequency.

Once I had a TV where the horizontal frequency (almost 16KHz) was audible. It
was unpleasant to be around for very long. IIRC, I sold it to someone with
hearing loss who couldn't hear it.

I could hear most of them.

What year?

I could also hear the detectors in stores
back when they were sonic. Not anymore though, and not because the
technology has changed, but because my hearing has changed.

Detectors?
--


Back in the 1970's, ultrasonic motion detectors for security systems were quite common in businesses. The last of the old Polaroid instant cameras used an ultrasonic transducer to measure distance to the subject of a picture and focus the camera. There were some ultrasonic motion detectors at one time that detected a shopper in the isle at a retailer so an electronic advertising display could start playing music and the voice of a pitchman. I haven't seen one for a while but I could hear the harmonics and clicks. ヽ(€¢€¿€¢)ノ

I can often hear ultrasonic mole scarers, but it might be they're faulty as they don't all do it. Although whenever I've said "isn't that annoying" to someone, they have no idea what I'm talking about. I tested myself at some science fair when I was 12, and I had better range than most.. And a doctor about 5 years ago did a hearing test and said I have better hearing than a kid (I'm 41).

--
I just sent my lawyer something for his birthday. Unfortunately, he wasn't home when it went off.

brought next idea :
On Mon, 26 Dec 2016 14:19:03 -0500, FromTheRafters
wrote:

What is the 'voltage drop' across the open contacts of such a switch?

The same as the max voltage supplied at the source.

That is not 'voltage drop', but is the answer I expected from trader_4.
Voltage drop is related to the energy dissipated primarily (but not
exclusively) through the heat created by the current 'flowing' through
the resistance. With no current 'flowing' there is no 'voltage drop' at
all. What you measure there across the open is the supply voltage.
Perhaps more correctly, you measure the voltage drop across the meter's
internal resistance when the meter 'completes' the circuit.

If current were 'flowing' and the wire had resistance *that* would be
'voltage drop'. Only when current is 'flowing', do wires have
resistance and dissipate energy.

A poster going by the nym Al Gebra suggested that Ohm's Law stated that
since the current is zero the voltage must be zero using the form V=IR
and I disagreed. Then trader+4, yourself and IIRC Clare agreed with Al
Gebra at that time. Now you seem to be saying that that isn't so.

Is the voltage zero as suggested by Al, or the same as the supply
voltage? Pick one.

As a thought experiment, consider a length of relatively thin wire
being monitored by an infrared sensor. Knowing other parameters, you
can deduce the 'voltage drop' by the heat being given off (no need to
complete the circuit with a meter). If the current gets too great the
resistance increases and the wire dissipates more and gives off more
heat and the voltage drop increases. Then, eventually, the wire opens,
and you no longer have any 'voltage drop' because there is no current,
but you *do* have supply voltage across the open.

On Monday, December 26, 2016 at 5:53:53 PM UTC-6, James Wilkinson Sword wrote:
On Mon, 26 Dec 2016 23:44:34 -0000, Uncle Monster wrote:

On Monday, December 26, 2016 at 12:01:49 PM UTC-6, James Wilkinson Sword wrote:
On Mon, 26 Dec 2016 14:22:02 -0000, FromTheRafters wrote:

Mark Lloyd explained on 12/25/2016 :
On 12/25/2016 03:26 PM, James Wilkinson Sword wrote:

[snip]

Hearing a 50Hz mains hum isn't that bad, but imagine hearing a higher
frequency.

Once I had a TV where the horizontal frequency (almost 16KHz) was audible. It
was unpleasant to be around for very long. IIRC, I sold it to someone with
hearing loss who couldn't hear it.

I could hear most of them.

What year?

I could also hear the detectors in stores
back when they were sonic. Not anymore though, and not because the
technology has changed, but because my hearing has changed.

Detectors?
--
Back in the 1970's, ultrasonic motion detectors for security systems were quite common in businesses. The last of the old Polaroid instant cameras used an ultrasonic transducer to measure distance to the subject of a picture and focus the camera. There were some ultrasonic motion detectors at one time that detected a shopper in the isle at a retailer so an electronic advertising display could start playing music and the voice of a pitchman. I haven't seen one for a while but I could hear the harmonics and clicks. ヽ(€¢€¿€¢)ノ

What I think's strange is motion detectors stay on when the alarm is deactivated. Why don't the PIRs only run at night?
--


The PIR motion detectors have and indicator light for a "walk test" to indicate that the unit is operating correctly and covering the area it's meant to. There is a jumper on the circuit board inside the PIR that can be moved to disable the walk test light but most security system installers just leave the jumper in place. ヽ(ヅ)ノ

[8~{} Uncle Infrared Monster

On Monday, December 26, 2016 at 5:55:41 PM UTC-6, James Wilkinson Sword wrote:
On Mon, 26 Dec 2016 23:44:34 -0000, Uncle Monster wrote:

On Monday, December 26, 2016 at 12:01:49 PM UTC-6, James Wilkinson Sword wrote:
On Mon, 26 Dec 2016 14:22:02 -0000, FromTheRafters wrote:

Mark Lloyd explained on 12/25/2016 :
On 12/25/2016 03:26 PM, James Wilkinson Sword wrote:

[snip]

Hearing a 50Hz mains hum isn't that bad, but imagine hearing a higher
frequency.

Once I had a TV where the horizontal frequency (almost 16KHz) was audible. It
was unpleasant to be around for very long. IIRC, I sold it to someone with
hearing loss who couldn't hear it.

I could hear most of them.

What year?

I could also hear the detectors in stores
back when they were sonic. Not anymore though, and not because the
technology has changed, but because my hearing has changed.

Detectors?
--
Back in the 1970's, ultrasonic motion detectors for security systems were quite common in businesses. The last of the old Polaroid instant cameras used an ultrasonic transducer to measure distance to the subject of a picture and focus the camera. There were some ultrasonic motion detectors at one time that detected a shopper in the isle at a retailer so an electronic advertising display could start playing music and the voice of a pitchman. I haven't seen one for a while but I could hear the harmonics and clicks. ヽ(€¢€¿€¢)ノ

I can often hear ultrasonic mole scarers, but it might be they're faulty as they don't all do it. Although whenever I've said "isn't that annoying" to someone, they have no idea what I'm talking about. I tested myself at some science fair when I was 12, and I had better range than most. And a doctor about 5 years ago did a hearing test and said I have better hearing than a kid (I'm 41).
--


You're still a kid at 41 years of age. I think one of the denizens of this group is approaching 90. ヽ(€¢€¿€¢)ノ

[8~{} Uncle Ancient Monster

On 12/26/2016 08:30 AM, trader_4 wrote:

[snip]

Why would you need to run 14/3 to every switch, when 14/2 already provides
both a hot and neutral to switches that are connected in the most common
way, ie from the source to the switch, then to the receptacle from there?
Every single pole switch in every house I've lived in has been wired that
way. The problems start where you don't have a neutral at the switch when
it's done backwards, ie source to receptacle, then to switch or a 3-way
switch that isn't connected to the source.


I added a receptacle in my bathroom, with the wires added to the light
switch box (which did have hot in it). However, now there were so many
wires there was no room for the switch. I but a blank cover over that
and added a new box below it for the switch (note that this was a narrow
section of wall, with no room for a 2-gang box). These boxes are
connected by a short piece of 14/3 (hot / neutral / switched hot).
Neutral was needed because I had a timer switch.

--
Mark Lloyd
http://notstupid.us/

"Nothing could be more anti-Biblical than letting women vote."
[Editorial, Harper's Magazine, November 1853]

On 12/26/2016 09:00 AM, trader_4 wrote:

All that is solved with a neutral there and it's no
big deal to run when you're installing a new circuit.


Considering having neutral in switch boxes, I have a few places where
I've installed receptacles next to switches. Normal wall receptacles can
be (and often are) behind things where they're hard to get to when you
need to plug something in temporarily. Those switch-height receptacles
are really used a lot.

--
Mark Lloyd
http://notstupid.us/

"Nothing could be more anti-Biblical than letting women vote."
[Editorial, Harper's Magazine, November 1853]

On 12/26/2016 11:52 AM, James Wilkinson Sword wrote:

[snip]


I have all the rooms bright, and the bedroom dimmer so it's not dazzling
when I wake up.


If you're watching TV, a ceiling light is likely to be in the wrong
place. That's one reason for using a lamp in the bedroom. The other is
to have a switch I can reach from bed (I need it DARK, and "night light"
is essentially a dirty word).

--
Mark Lloyd
http://notstupid.us/

"Nothing could be more anti-Biblical than letting women vote."
[Editorial, Harper's Magazine, November 1853]

On 12/26/2016 11:54 AM, James Wilkinson Sword wrote:

[snip]

Called 3-way in the US. I think I understand why, but 2-way sounds more
reasonable.

It can be 3-way (or more) if you want, you add a switch in the middle
that swaps the poles. But if there's two switches, calling it 3-way is
illogical.

IIRC, what I heard is that its called 3-way because there's wiring going
to 3 places (each switch, and the light). It does sound strange. I'd
like to use 3-way for THREE switches.

[snip]

--
Mark Lloyd
http://notstupid.us/

"Nothing could be more anti-Biblical than letting women vote."
[Editorial, Harper's Magazine, November 1853]

On 12/26/2016 12:01 PM, James Wilkinson Sword wrote:

[snip]

Once I had a TV where the horizontal frequency (almost 16KHz) was
audible. It
was unpleasant to be around for very long. IIRC, I sold it to someone
with
hearing loss who couldn't hear it.

I could hear most of them.

What year?


IIRC, around 1995, 20-inch RCA.

[snip]

--
Mark Lloyd
http://notstupid.us/

"Nothing could be more anti-Biblical than letting women vote."
[Editorial, Harper's Magazine, November 1853]

On 12/26/2016 12:40 PM, wrote:
On Mon, 26 Dec 2016 18:00:06 -0000, "James Wilkinson Sword"
wrote:

All in all, I think code is a
good idea, including the new reqt to have a neutral at all switch locations.

Making convenience a law is insanity.

That convenience is what allows you to use PIR detectors on CFL and
LED lamps.

That kind of PIR switch is something I'm looking for (I'd like to use
then in a couple of boxes with neutrals).

The old 'Power through the load" (2 wire) designs only work with an
incandescent or magnetic ballast load.


I have a couple of the old ones that sort of work with CFLs. They don't
go completely off but flicker all the time. Another flickered all the
time but WOULDN'T go on.

--
Mark Lloyd
http://notstupid.us/

"Nothing could be more anti-Biblical than letting women vote."
[Editorial, Harper's Magazine, November 1853]