A friend who is an electrical engineer said to switch the lives on a lighting circuit but I have also read somewhere to switch neutrals...who is right??

Thanks

deffinatley your friend is right ,
I am also an electrician , switching the neutral will make the light work normally , but it leaves you problem of where to tie up your horse .

"joey1522" wrote in message
...

A friend who is an electrical engineer said to switch the lives on a
lighting circuit but I have also read somewhere to switch
neutrals...who is right??


This has got to be a troll....

Put it another way, I hope it is ! :~(

:::Jerry:::: wrote:
"joey1522" wrote in message
...

A friend who is an electrical engineer said to switch the lives on a
lighting circuit but I have also read somewhere to switch
neutrals...who is right??



This has got to be a troll....

Put it another way, I hope it is ! :~(


Doesn't he mean he "...switch neutrals as well" (ie, use a DP switch)?

joey1522 wrote:
A friend who is an electrical engineer said to switch the lives on a
lighting circuit but I have also read somewhere to switch
neutrals...who is right??

Your friend is a true friend. Your friend is on your side. Your friend
wants to see you live to a ripe old age.

The 'somewhere' you read was the work of the Devil. The Devil wants you
to fry. The Devil is making you imagine you read this lunatic idea of
switching the neutral.

Back in the realms of the rational... the neutral is firmly connected to
earth potential; under no-fault conditions the neutral is 'safe' (won't
do you harm if you touch it alone, while in contact with the mass of
earth). By contrast, the live side is doing rapid oscillations, 50 times
a second, shooting up to something like 340V above earth potential,
sinking increasingly quickly down to earth potential, dropping past it
just as fast as it came towards it, ending up at something like 340V
below earth potential, and zooming back up again through 0V back to the
340V-above mark.

That's something you don't want to be touching - say, if you're clumsy
enough to touch the pin in the lampholder that's connected to the live.
Ow. That would give you an unpleasant tingle; or, if you were resting
against an earthed surface like the kitchen sink, kill you. Oops.

Hence, we switch the *live* side. That way, when it's off, it's *off*,
unlikely to hurt (or kill) us.

If we're smart, we don't go sticking our fingers into something that
alleged to be switched off, mind: it's always possible that someone was
listening to the Devil when they wired up their lighting... or that
someone under the Devil's influence swapped over the red and black wires
(brown and blue in the Modern world) somewhere further back in the
circuit, and the Devil made them forget to independently test that the
red (brown) wire really was the Live one and the black (blue) one Neutral.

It's not even funny. Switches go on the live side.

It's so not funny that many of the regulars will suspect your posting is
a fake to encourage the NICEIC profit-making myth that d-i-y'ers are all
too incompetent to touch their house electrics - a myth whose complement
is rapidly dispelled by spending a little time spent browsing the IEE
Forum where the pros gather... but I digress.

Switches go in the LIVE side.

Happy?

"Lobster" wrote in message
...
:::Jerry:::: wrote:
"joey1522" wrote in message
...

A friend who is an electrical engineer said to switch the lives on a
lighting circuit but I have also read somewhere to switch
neutrals...who is right??



This has got to be a troll....

Put it another way, I hope it is ! :~(


Doesn't he mean he "...switch neutrals as well" (ie, use a DP switch)?


Well, that is a possibility I suppose...

Stefek Zaba wrote:

Switches go in the LIVE side.

I can safely say that in this case nobody is going to accuse you of
overzealous caution "a-la Lurch" ...

:::Jerry:::: wrote:


Doesn't he mean he "...switch neutrals as well" (ie, use a DP switch)?


Well, that is a possibility I suppose...

But not really in a lighting circuit, however.

"Stefek Zaba" wrote
| Doesn't he mean he "...switch neutrals as well" (ie, use a DP switch)?
| Well, that is a possibility I suppose...
| But not really in a lighting circuit, however.

The exception would be to an extractor fan (which if it's a timer over run
model will require a triple pole fan isolator for live / switched live /
neutral).

Owain

On Sat, 22 Jan 2005 20:22:21 -0000, "Owain"
wrote:

"Stefek Zaba" wrote
| Doesn't he mean he "...switch neutrals as well" (ie, use a DP switch)?
| Well, that is a possibility I suppose...
| But not really in a lighting circuit, however.

The exception would be to an extractor fan (which if it's a timer over run
model will require a triple pole fan isolator for live / switched live /
neutral).

I have another exception. I have a wall lamp in the porch, fed from a
hole drilled through from a disused back-box. Many moons ago I wired a
feed into the back-box from a loop-in from the living-room light. It
was convenient to use a two pole switch here, really as a handy way to
extend the neutral into the porch.

It was a shot in the dark drilling the hole from the switch position
at an angle of some 45 degrees, with a two-foot long masonry bit. As
it happened it came through at just the desired point in the porch!

--
Frank Erskine

"Stefek Zaba" wrote in message
...
joey1522 wrote:
A friend who is an electrical engineer said to switch the lives on a
lighting circuit but I have also read somewhere to switch
neutrals...who is right??

Your friend is a true friend. Your friend is on your side. Your friend
wants to see you live to a ripe old age.

The 'somewhere' you read was the work of the Devil. The Devil wants you
to fry. The Devil is making you imagine you read this lunatic idea of
switching the neutral.

Back in the realms of the rational... the neutral is firmly connected to
earth potential; under no-fault conditions the neutral is 'safe' (won't
do you harm if you touch it alone, while in contact with the mass of
earth).

You obviously do not live in a rural location with a PME installation :-)

42 volts of 'bite' on neutral or 'earth' convinced me to change the earthing
arrangements toute suite.

"Stefek Zaba" wrote in message
...
Switches go in the LIVE side.

So why do we have to spend a fortune on two pole cooker, fan and everything
else other than lighting switches ?

On Sun, 23 Jan 2005 00:15:31 -0000, "Mike" strung
together this:

Switches go in the LIVE side.

So why do we have to spend a fortune on two pole cooker, fan and everything
else other than lighting switches ?

That should really read;

All single pole switches should go in the live (phase) conductor only.

In answer to your query, all fixed equipment requires double pole
isolation. Lightswitches are for functional switching and single pole
switching should be in the live (phase) conductor *ONLY*.
--

SJW
Please reply to group or use 'usenet' in email subject

Lurch wrote:

In answer to your query, all fixed equipment requires double pole
isolation.

ahh, that pre-empted a question that was rattling around in my head, why
_3_ pole isolator was needed for timer fans.

Stefek Zaba wrote:

The 'somewhere' you read was the work of the Devil. The Devil wants you
to fry. The Devil is making you imagine you read this lunatic idea of
switching the neutral.

The somewhere could also have been an avionics wiring manual (where is
it standard practice to switch the returns.... ;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article ,
Andy Burns wrote:
In answer to your query, all fixed equipment requires double pole
isolation.

ahh, that pre-empted a question that was rattling around in my head, why
_3_ pole isolator was needed for timer fans.

Because they have a permanent live for the timer circuit as well as a
switched live from the light. Hence the need for a three pole to totally
isolate them.

--
*If one synchronized swimmer drowns, do the rest have to drown too?

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

Because they have a permanent live for the timer circuit as well as a
switched live from the light. Hence the need for a three pole to totally
isolate them.

Thanks, but as I said lurch pre-empted (rather than prompted) my
question, I could see why you'd need to isolate the permanent and
switched lives, but not why you'd need to isolate the neutral.

Actually I still do wonder *why* (apart from "them is the rules") I mean
a ceiling rose is fixed wiring and you can't individually isolate
neutral from that ... so why is it deemed necessary to do so on fixed
equipment such as the fan?

"Andy Burns" wrote in message
...
Dave Plowman (News) wrote:

Because they have a permanent live for the timer circuit as well as a
switched live from the light. Hence the need for a three pole to totally
isolate them.

Thanks, but as I said lurch pre-empted (rather than prompted) my
question, I could see why you'd need to isolate the permanent and
switched lives, but not why you'd need to isolate the neutral.

Actually I still do wonder *why* (apart from "them is the rules") I mean
a ceiling rose is fixed wiring and you can't individually isolate
neutral from that ... so why is it deemed necessary to do so on fixed
equipment such as the fan?

What if some twerp has reversed the positive and neutral connections at some
point further back in the circuit ?...

With 'portable appliances' you can isolate them by pulling the plug out -
not so with fixed appliances IYSWIM.

:::Jerry:::: wrote:
"Andy Burns" wrote in message
...

Dave Plowman (News) wrote:


Because they have a permanent live for the timer circuit as well as a
switched live from the light. Hence the need for a three pole to totally
isolate them.

Thanks, but as I said lurch pre-empted (rather than prompted) my
question, I could see why you'd need to isolate the permanent and
switched lives, but not why you'd need to isolate the neutral.

Actually I still do wonder *why* (apart from "them is the rules") I mean
a ceiling rose is fixed wiring and you can't individually isolate
neutral from that ... so why is it deemed necessary to do so on fixed
equipment such as the fan?


What if some twerp has reversed the positive and neutral connections at some
point further back in the circuit ?...

With 'portable appliances' you can isolate them by pulling the plug out -
not so with fixed appliances IYSWIM.

Or lightbulbs? ;-)

David

"John Rumm" wrote in message
...
Stefek Zaba wrote:

The 'somewhere' you read was the work of the Devil. The Devil wants you
to fry. The Devil is making you imagine you read this lunatic idea of
switching the neutral.

The somewhere could also have been an avionics wiring manual (where is
it standard practice to switch the returns.... ;-)




or perhaps modern automotive practices - my brother (trained landrover &
renault technician) tells me that switched returns are now commonplace.
Can't remember why he said that was. Something about increased longevity of
the switches or components I think.



--
Richard Sampson

mail me at
richard at olifant d-ot co do-t uk

On Sun, 23 Jan 2005 11:54:00 -0000, ":::Jerry::::"
strung together this:

What if some twerp has reversed the positive and neutral connections at some
point further back in the circuit ?...

With 'portable appliances' you can isolate them by pulling the plug out -
not so with fixed appliances IYSWIM.

Sorry, you've lost me here. I'm not quite sure what your question is.
--

SJW
Please reply to group or use 'usenet' in email subject

On Sun, 23 Jan 2005 18:18:49 -0000, "RichardS"
strung together this:

or perhaps modern automotive practices - my brother (trained landrover &
renault technician) tells me that switched returns are now commonplace.
Can't remember why he said that was. Something about increased longevity of
the switches or components I think.

Many domestic appliances use switched neutrals for some reason so all
the copmponents have a permanant live feed. I think it's something to
do with spikes and surges through equipment at switch-on.
--

SJW
Please reply to group or use 'usenet' in email subject

"Lurch" wrote in message
...
On Sun, 23 Jan 2005 18:18:49 -0000, "RichardS"
strung together this:

or perhaps modern automotive practices - my brother (trained landrover &
renault technician) tells me that switched returns are now commonplace.
Can't remember why he said that was. Something about increased longevity
of
the switches or components I think.

It's so they can easily use N type power mosfet switches which have less
loss than P types or N types used in high side switching.