Three phase wiring
 

In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.

--
*All generalizations are false.

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

Three phase wiring
 

On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


Never seen that. I have seen triple red and earth.

And a black core would suggest the intention was to use a neutral?

--
Adam

Three phase wiring
 

On 8 Feb 2021 at 17:38:55 GMT, "ARW" wrote:

On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


Never seen that. I have seen triple red and earth.

And a black core would suggest the intention was to use a neutral?

Could it be intended for looping in a succession light fittings with switched
live from a smaller number of switches being connected between them?

--
Roger Hayter

Three phase wiring
 

On 09/02/2021 13:24, Roger Hayter wrote:
On 8 Feb 2021 at 17:38:55 GMT, "ARW" wrote:

On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


Never seen that. I have seen triple red and earth.

And a black core would suggest the intention was to use a neutral?

Could it be intended for looping in a succession light fittings with switched
live from a smaller number of switches being connected between them?


No idea.

--
Adam

Three phase wiring
 

On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


I found some old red white and blue (with no earth) stranded 3 core a
few months ago.

The white changed to yellow in 1966 when I believe that the compulsory
earth was added.

--
Adam

Three phase wiring
 

On 09/02/2021 17:54, ARW wrote:
On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


I found some old red white and blue (with no earth) stranded 3 core a
few months ago.

The white changed to yellow in 1966 when I believe that the compulsory
earth was added.

From the thread I started a couple of years ago with the subject "Old
wiring":

"The old metal-cased picture light came off easily enough, to reveal a
connection to red and blue wiring (it was not earthed)! The cable was
plastered in, but digging some of the plaster out revealed white PVC
cable. A bit more digging, and a cut-off third conductor with very light
yellow (maybe off-white?) insulation appeared. Then a cut-off bare earth
wire. So it looks like someone used some spare 3-phase cable for this
lighting circuit. Sigh."

This place was built from 1965 to 1966, and /some/ of the lighting
wiring is earthed.

--

Jeff

Three phase wiring
 

In article ,
ARW wrote:
On 09/02/2021 13:24, Roger Hayter wrote:
On 8 Feb 2021 at 17:38:55 GMT, "ARW" wrote:

On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


Never seen that. I have seen triple red and earth.

And a black core would suggest the intention was to use a neutral?

Could it be intended for looping in a succession light fittings with switched
live from a smaller number of switches being connected between them?


No idea.

I'm not sure either. To follow the convention of the day, if using for
switching two lights, it would be one red and two blacks. I bought it from
a local place that was big on Exchange and Mart. Makes perhaps some sense
for a room thermostat. But only some.

--
*Give me ambiguity or give me something else.

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

Three phase wiring
 

On Friday, 12 February 2021 at 15:08:22 UTC, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 09/02/2021 13:24, Roger Hayter wrote:
On 8 Feb 2021 at 17:38:55 GMT, "ARW" wrote:

On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


Never seen that. I have seen triple red and earth.

And a black core would suggest the intention was to use a neutral?

Could it be intended for looping in a succession light fittings with switched
live from a smaller number of switches being connected between them?


No idea.
I'm not sure either. To follow the convention of the day, if using for
switching two lights, it would be one red and two blacks. I bought it from
a local place that was big on Exchange and Mart. Makes perhaps some sense
for a room thermostat. But only some.

--
*Give me ambiguity or give me something else.
Dave Plowman London SW
To e-mail, change noise into sound.

I suppose all three cores in a triple and earth should have been all red in the past and all brown currently since at some point in two way lighting they are all live/line with the common always live.

Richard

Three phase wiring
 

On 12 Feb 2021 at 17:10:41 GMT, "Tricky Dicky" wrote:

On Friday, 12 February 2021 at 15:08:22 UTC, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 09/02/2021 13:24, Roger Hayter wrote:
On 8 Feb 2021 at 17:38:55 GMT, "ARW" wrote:

On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


Never seen that. I have seen triple red and earth.

And a black core would suggest the intention was to use a neutral?

Could it be intended for looping in a succession light fittings with
switched
live from a smaller number of switches being connected between them?


No idea.
I'm not sure either. To follow the convention of the day, if using for
switching two lights, it would be one red and two blacks. I bought it from
a local place that was big on Exchange and Mart. Makes perhaps some sense
for a room thermostat. But only some.

--
*Give me ambiguity or give me something else.
Dave Plowman London SW
To e-mail, change noise into sound.

I suppose all three cores in a triple and earth should have been all red in
the past and all brown currently since at some point in two way lighting they
are all live/line with the common always live.

Richard

Nuisance to wire if you have to use some kind of circuit tracing device to
know which is the common wire at the other end, though.


--
Roger Hayter

Three phase wiring
 

On 12/02/2021 21:12, Roger Hayter wrote:
On 12 Feb 2021 at 17:10:41 GMT, "Tricky Dicky" wrote:

On Friday, 12 February 2021 at 15:08:22 UTC, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 09/02/2021 13:24, Roger Hayter wrote:
On 8 Feb 2021 at 17:38:55 GMT, "ARW" wrote:

On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


Never seen that. I have seen triple red and earth.

And a black core would suggest the intention was to use a neutral?

Could it be intended for looping in a succession light fittings with
switched
live from a smaller number of switches being connected between them?


No idea.
I'm not sure either. To follow the convention of the day, if using for
switching two lights, it would be one red and two blacks. I bought it from
a local place that was big on Exchange and Mart. Makes perhaps some sense
for a room thermostat. But only some.

--
*Give me ambiguity or give me something else.
Dave Plowman London SW
To e-mail, change noise into sound.

I suppose all three cores in a triple and earth should have been all red in
the past and all brown currently since at some point in two way lighting they
are all live/line with the common always live.

Richard

Nuisance to wire if you have to use some kind of circuit tracing device to
know which is the common wire at the other end, though.



Now it's a while since I last stripped out a conduit install using the
old cotton insulated cables. But yes they did use blacks and reds for
two way switching - presumably to identify the perm live and switched
live. But this was in singles and not 3 core and earth.

With 3 red/brown core and earth you can identify the cores by the layout
with respect to the earth (and no I am not going to call it a cpc). ie
red1 earth red2 red3 is the same at both ends.

Just to note that when using singles the wiring for 2 way switching was
different to todays standard setup.



--
Adam

Three phase wiring
 

On 13 Feb 2021 at 07:52:44 GMT, "ARW" wrote:

On 12/02/2021 21:12, Roger Hayter wrote:
On 12 Feb 2021 at 17:10:41 GMT, "Tricky Dicky" wrote:

On Friday, 12 February 2021 at 15:08:22 UTC, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 09/02/2021 13:24, Roger Hayter wrote:
On 8 Feb 2021 at 17:38:55 GMT, "ARW" wrote:

On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


Never seen that. I have seen triple red and earth.

And a black core would suggest the intention was to use a neutral?

Could it be intended for looping in a succession light fittings with
switched
live from a smaller number of switches being connected between them?


No idea.
I'm not sure either. To follow the convention of the day, if using for
switching two lights, it would be one red and two blacks. I bought it from
a local place that was big on Exchange and Mart. Makes perhaps some sense
for a room thermostat. But only some.

--
*Give me ambiguity or give me something else.
Dave Plowman London SW
To e-mail, change noise into sound.

I suppose all three cores in a triple and earth should have been all red in
the past and all brown currently since at some point in two way lighting
they
are all live/line with the common always live.

Richard

Nuisance to wire if you have to use some kind of circuit tracing device to
know which is the common wire at the other end, though.



Now it's a while since I last stripped out a conduit install using the
old cotton insulated cables. But yes they did use blacks and reds for
two way switching - presumably to identify the perm live and switched
live. But this was in singles and not 3 core and earth.

With 3 red/brown core and earth you can identify the cores by the layout
with respect to the earth (and no I am not going to call it a cpc). ie
red1 earth red2 red3 is the same at both ends.

Hadn't thought of that. But did they have earth wires in the old days?




Just to note that when using singles the wiring for 2 way switching was
different to todays standard setup.

I guess you could have live on one switch common and switched live on the
other. Is there any other way than that?

--
Roger Hayter

Three phase wiring
 

On 06/02/2021 23:14, Theo wrote:
While I was on the TLC website I was doing a thought experiment.

Twin and earth cable comes in a variety of sizes:
1, 1.5, 2.5, 4, 6, 10, 16 mm2.

But what if you want to wire three phase? TLC only have 1 and 1.5mm2 three
core and earth. Doncaster Cables also have 2.5mm2 but not larger. CEF
likewise. There's some three core in SWA but I assume that's primarily for
external use?

I understand that using three phase you can get 3x the power compared to
single phase - so a 32A radial would get you 7.3kW single phase or 22kW
three phase.

But how should you wire that? For a 32A single phase radial the TLC
calculator indicates it needs 6mm2. What cable do you use for three phase?...

In my factories, most machines were hard wired into the supply, using
single core conduit wiring cable, running through trunking, rigid
conduit or flexible conduit. Using that, 32A would need 4mm2.


--
Colin Bignell

Three phase wiring
 

On Friday, 12 February 2021 at 21:12:11 UTC, Roger Hayter wrote:
On 12 Feb 2021 at 17:10:41 GMT, "Tricky Dicky" wrote:

On Friday, 12 February 2021 at 15:08:22 UTC, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 09/02/2021 13:24, Roger Hayter wrote:
On 8 Feb 2021 at 17:38:55 GMT, "ARW" wrote:

On 08/02/2021 00:48, Dave Plowman (News) wrote:
In article ,
ARW wrote:
On 07/02/2021 14:12, Dave Plowman (News) wrote:
In article ,
newshound wrote:
That's simply because 3+e is made for two-way lighting

Then it makes no sense to use three phase wiring colours.



Well you cannot just use 3 browns can you?

Triple and earth for two way switch circuits had two reds and a black.
Shows you how old my drum of it is.


Never seen that. I have seen triple red and earth.

And a black core would suggest the intention was to use a neutral?

Could it be intended for looping in a succession light fittings with
switched
live from a smaller number of switches being connected between them?


No idea.
I'm not sure either. To follow the convention of the day, if using for
switching two lights, it would be one red and two blacks. I bought it from
a local place that was big on Exchange and Mart. Makes perhaps some sense
for a room thermostat. But only some.

--
*Give me ambiguity or give me something else.
Dave Plowman London SW
To e-mail, change noise into sound.

I suppose all three cores in a triple and earth should have been all red in
the past and all brown currently since at some point in two way lighting they
are all live/line with the common always live.

Richard
Nuisance to wire if you have to use some kind of circuit tracing device to
know which is the common wire at the other end, though.


--
Roger Hayter

I agree. As far as I am aware there are no set standards for which colour should be used where, although with modern three core wire I suppose brown should be COM as it is the permanent live leaving black and grey as the two switched lives.

Even the term Common in DC circuits is usually the negative (-) connection yet in two way lighting it is the live/line.

Richard

Three phase wiring
 

On 13/02/2021 10:07, Roger Hayter wrote:
On 13 Feb 2021 at 07:52:44 GMT, "ARW" wrote:

Just to note that when using singles the wiring for 2 way switching was
different to todays standard setup.

I guess you could have live on one switch common and switched live on the
other. Is there any other way than that?


For singles that is pretty standard.

When using a 3 core as the strapper then would normally you would have
perm live at L1 and switched live at L2 at the same switch and just
match up the second switch terminals using the 3 core.

--
Adam

Three phase wiring
 

On 13 Feb 2021 at 15:39:19 GMT, "ARW" wrote:

On 13/02/2021 10:07, Roger Hayter wrote:
On 13 Feb 2021 at 07:52:44 GMT, "ARW"
wrote:

Just to note that when using singles the wiring for 2 way switching was
different to todays standard setup.

I guess you could have live on one switch common and switched live on the
other. Is there any other way than that?


For singles that is pretty standard.

Don't you tend to end up in an ordinary house with the live supplied from the
opposite floor to the light fitting?




When using a 3 core as the strapper then would normally you would have
perm live at L1 and switched live at L2 at the same switch and just
match up the second switch terminals using the 3 core.

Ok, that latter is the popular thing nowadays, but I can't think of any third
way to do it?


--
Roger Hayter