Hello,

I wish to use some X10 transmitters within some [existing] light switches
(like these: http://www.homeautomation.eu.com/category/6), however they
require a neutral connection as well as live - and as everyone knows this
does not exist in a typical UK light switch.
Dropping a new neutral wire to existing switches would be impossible except
when each room is being decorated.

So, I'm looking at alternatives. One idea is to see about using earth as
neutral for this as it's just a reference point for the X10 signal. As
netural will be commoned to earth somewhere (incoming supply? substation?)
what reasons are there not to do this?
We're not talking about putting a load between live and earth, just using
earth as a reference point for a signal to be transmitted on the live line
from.
Can I common up netural and earth in the CU?? I've yet to see what voltage
is between them but last time I looked a few years back it was only a few
volts.

Any other suggestions to get this working?

Alan.

IANAEE (I'm not an electrical engineer etc...)

On Tue, 01 Feb 2005 12:23:39 +0000, Alan wrote:

Hello,

I wish to use some X10 transmitters within some [existing] light
switches (like these: http://www.homeautomation.eu.com/category/6),
however they require a neutral connection as well as live - and as
everyone knows this does not exist in a typical UK light switch.
Dropping a new neutral wire to existing switches would be impossible
except when each room is being decorated.

So, I'm looking at alternatives. One idea is to see about using earth as
neutral for this as it's just a reference point for the X10 signal. As
netural will be commoned to earth somewhere (incoming supply?
substation?) what reasons are there not to do this?

No - *don't* do this. The earth or CPC is designed for one main purpose
only, to carry off fault currents (and provide equipotential bonding with
respect to the ground). That's probably not the best (or even fully
correct) explanation, but it'll do for starters.

Doing anything else with the earth would be fundamentally bad practise.

Also, if these X10 devices do pass even a few mA then between them and you
install a few they might trip an RCD should you happen to have a 30mA one
covering the whole installation.

We're not talking about putting a load between live and earth, just
using earth as a reference point for a signal to be transmitted on the
live line from.

Understand. Really though - it is a fundamentally bad idea to use the earth.
Sorry I explain why any better.

Can I common up netural and earth in the CU?? I've yet to see what
voltage is between them but last time I looked a few years back it was
only a few volts.

Definately *don't* do this. Your electricity supplier will have a stated
way of providing an earth (or not in some cases). You must not interfere
with it. If, for example, they provide a seperate earth or CPC via the
supply cable, commoned back at the substation, then you can get some
potential difference between your neutral and earth. Connecting them in an
unauthorised way can give rise to large currents and generally annoys
electricity suppliers, apart from being dangerous.

My father saw a case once where a screw in a wall had gone through a cable
shorting the earth and neutral. Apparantly it got rather hot, to the point
of being a fire risk. It didn't blow any fuses because there were'nt any
in the neutral circuit.

Any other suggestions to get this working?

Well... Tricky one. I see you've found a funky X10 device I've not come
across before, if you mean Micromodule AW12.

Here's an idea:

Another way might be to use a different X10 setup with a remote X10
receiver controlling the light (install somewhere safe and convenient
where you can get the lighting supply and light pendant cables to it.

Then see if you can find a pure X10 single-address transmitter that looks
like a light switch, but isn't expecting the load to be wired in directly
to it. You might even be able to use some of the other X10 switch products
and just ignore the switched live output, and put the switch and the
receiver on the same address. Best to check with the manufacturer if in
any doubt - they're usually pretty helpful if you phone or email them.

*disclaimer*

I haven't done all the research into this myself, so these are just ideas,
may or may not be practical and and before Lurch jumps in and tells you
I've just suggested something dangerous (he means well and I'm fairly sure
I haven't!) it's upto to you to (as always with any online advice) to
consider your final solution and be satisfied that it's safe and correct.

HTH

Timbo

On Tue, 01 Feb 2005 12:23:39 GMT, "Alan"
strung together this:

So, I'm looking at alternatives. One idea is to see about using earth as
neutral for this as it's just a reference point for the X10 signal. As
netural will be commoned to earth somewhere (incoming supply? substation?)
what reasons are there not to do this?
We're not talking about putting a load between live and earth, just using
earth as a reference point for a signal to be transmitted on the live line
from.
Can I common up netural and earth in the CU?? I've yet to see what voltage
is between them but last time I looked a few years back it was only a few
volts.

Not a good idea, this is classed as a total bodge and can be quite
lethal. It is contravention of every regulation out there.

Any other suggestions to get this working?

Drop a neutral to the switch, i.e. do it properly or not at all.
--

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

On Tue, 01 Feb 2005 12:23:39 +0000, Alan wrote:


Can I common up netural and earth in the CU?? I've yet to see what
voltage is between them but last time I looked a few years back it was
only a few volts.

On an aside, the reason there's a few volts there is due to the the
impedance of a fairly hefty neutral core in the street supply cable
between the consumers and the substation.

It might be a few volts, but if you provide a second path for the neutral
current to return to the transformer (via the ground) then proportion of
that current[1] will be diverted via your earth and your common joint.
That's going to get hot. Also, if your neutral suffers a fault further up
the line you're in danger of everything in your house rising to some
undesireable voltage.

There are types of supply earth where something like this is done but the
suppliers know what they are doing more than you or me ;-/ And they design
it work in that way.

[1] Not just your current, but any other neutral current in your area will
back feed to your earth bond)

Timbo

"Tim" wrote in message
news
IANAEE (I'm not an electrical engineer etc...)

On Tue, 01 Feb 2005 12:23:39 +0000, Alan wrote:

Hello,

I wish to use some X10 transmitters within some [existing] light
switches (like these: http://www.homeautomation.eu.com/category/6),
however they require a neutral connection as well as live - and as
everyone knows this does not exist in a typical UK light switch.
Dropping a new neutral wire to existing switches would be impossible
except when each room is being decorated.

So, I'm looking at alternatives. One idea is to see about using earth as
neutral for this as it's just a reference point for the X10 signal. As
netural will be commoned to earth somewhere (incoming supply?
substation?) what reasons are there not to do this?

No - *don't* do this. The earth or CPC is designed for one main purpose
only, to carry off fault currents (and provide equipotential bonding with
respect to the ground). That's probably not the best (or even fully
correct) explanation, but it'll do for starters.

Doing anything else with the earth would be fundamentally bad practise.

Also, if these X10 devices do pass even a few mA then between them and you
install a few they might trip an RCD should you happen to have a 30mA one
covering the whole installation.

We're not talking about putting a load between live and earth, just
using earth as a reference point for a signal to be transmitted on the
live line from.

Understand. Really though - it is a fundamentally bad idea to use the
earth.
Sorry I explain why any better.

Can I common up netural and earth in the CU?? I've yet to see what
voltage is between them but last time I looked a few years back it was
only a few volts.

Definately *don't* do this. Your electricity supplier will have a stated
way of providing an earth (or not in some cases). You must not interfere
with it. If, for example, they provide a seperate earth or CPC via the
supply cable, commoned back at the substation, then you can get some
potential difference between your neutral and earth. Connecting them in an
unauthorised way can give rise to large currents and generally annoys
electricity suppliers, apart from being dangerous.

My father saw a case once where a screw in a wall had gone through a cable
shorting the earth and neutral. Apparantly it got rather hot, to the point
of being a fire risk. It didn't blow any fuses because there were'nt any
in the neutral circuit.

Any other suggestions to get this working?

Well... Tricky one. I see you've found a funky X10 device I've not come
across before, if you mean Micromodule AW12.

Here's an idea:

Another way might be to use a different X10 setup with a remote X10
receiver controlling the light (install somewhere safe and convenient
where you can get the lighting supply and light pendant cables to it.

Then see if you can find a pure X10 single-address transmitter that looks
like a light switch, but isn't expecting the load to be wired in directly
to it. You might even be able to use some of the other X10 switch products
and just ignore the switched live output, and put the switch and the
receiver on the same address. Best to check with the manufacturer if in
any doubt - they're usually pretty helpful if you phone or email them.

*disclaimer*

I haven't done all the research into this myself, so these are just ideas,
may or may not be practical and and before Lurch jumps in and tells you
I've just suggested something dangerous (he means well and I'm fairly sure
I haven't!) it's upto to you to (as always with any online advice) to
consider your final solution and be satisfied that it's safe and correct.

HTH

Timbo

..........And this is why I posted here before trying anything! It's easier
to ask for advise and workarounds than find out the hard way when it all
goes wrong!
Hmmmm. Getting neutral to the switches is going to be a PITA.

How about using the 4th core of the three core & earth to the existing
two-way switches - and letting X10 take care of the 2 way switching needs?
Then the cores will become live, switched live, neutral and earth...?
2 of the switches I wish to control are part of a 2 way switching
arrangement so this could be reasonably easy to do.

Alan.

Alan wrote:

How about using the 4th core of the three core & earth to the existing
two-way switches - and letting X10 take care of the 2 way switching needs?
Then the cores will become live, switched live, neutral and earth...?
2 of the switches I wish to control are part of a 2 way switching
arrangement so this could be reasonably easy to do.

Yes, this one's good: this is a pretty common usage of 3+E when wiring
fans with a run-on timer, for example, and is much cleaner than
dribbling return currents to earth or to some other circuit's neutral.

On Tue, 01 Feb 2005 14:09:57 +0000, Alan wrote:

Then see if you can find a pure X10 single-address transmitter that
looks like a light switch, but isn't expecting the load to be wired in
directly to it. You might even be able to use some of the other X10
switch products and just ignore the switched live output, and put the
switch and the receiver on the same address. Best to check with the
manufacturer if in any doubt - they're usually pretty helpful if you
phone or email them.

I probably should clarify that you could, with the above method, just rewire
the existing swich cable from up above the ceiling to be across the L+N of the
lighting circuit which allows you to leave the existing cable in place.

The X10 switch gets its feed and no need for the load supply wire as
that's handled by the remote X10 receiver module.

.........And this is why I posted here before trying anything! It's
easier to ask for advise and workarounds than find out the hard way when
it all goes wrong!

Hmmmm. Getting neutral to the switches is going to be a PITA.

How about using the 4th core of the three core & earth to the existing
two-way switches - and letting X10 take care of the 2 way switching
needs? Then the cores will become live, switched live, neutral and
earth...? 2 of the switches I wish to control are part of a 2 way
switching arrangement so this could be reasonably easy to do.

Stefek answered this already, it's a perfectly good way to do it.

Let us know how you get on - I'm thinking of maybe using X10 for some
garden lighting (rather than running lots of SWA back to the house, I can
just run one lighting supply circuit and use the DIN rail X10 modules in
waterproof housings near each set of lights). Could be a good setup for
the pond too...

Best,

Timbo

"Tim" wrote in message
news
On Tue, 01 Feb 2005 14:09:57 +0000, Alan wrote:

Then see if you can find a pure X10 single-address transmitter that
looks like a light switch, but isn't expecting the load to be wired in
directly to it. You might even be able to use some of the other X10
switch products and just ignore the switched live output, and put the
switch and the receiver on the same address. Best to check with the
manufacturer if in any doubt - they're usually pretty helpful if you
phone or email them.

I probably should clarify that you could, with the above method, just
rewire
the existing swich cable from up above the ceiling to be across the L+N of
the
lighting circuit which allows you to leave the existing cable in place.

The X10 switch gets its feed and no need for the load supply wire as
that's handled by the remote X10 receiver module.

.........And this is why I posted here before trying anything! It's
easier to ask for advise and workarounds than find out the hard way when
it all goes wrong!

Hmmmm. Getting neutral to the switches is going to be a PITA.

How about using the 4th core of the three core & earth to the existing
two-way switches - and letting X10 take care of the 2 way switching
needs? Then the cores will become live, switched live, neutral and
earth...? 2 of the switches I wish to control are part of a 2 way
switching arrangement so this could be reasonably easy to do.

Stefek answered this already, it's a perfectly good way to do it.

Let us know how you get on - I'm thinking of maybe using X10 for some
garden lighting (rather than running lots of SWA back to the house, I can
just run one lighting supply circuit and use the DIN rail X10 modules in
waterproof housings near each set of lights). Could be a good setup for
the pond too...

Best,

Timbo

Tim,

X10 will do this easily - I have a similar setup but have the modules in the
garage, all fed via a SWA to the house.
Works great.
Current project is trying to get X10 control of existing lights with the
minimum of disruption to each room to keep SWMBO happy!

Alan.

Alan wrote:

Let us know how you get on - I'm thinking of maybe using X10 for some
garden lighting (rather than running lots of SWA back to the house,
I can just run one lighting supply circuit and use the DIN rail X10
modules in waterproof housings near each set of lights). Could be a
good setup for the pond too...


X10 will do this easily - I have a similar setup but have the modules
in the garage, all fed via a SWA to the house.
Works great.
Current project is trying to get X10 control of existing lights with
the minimum of disruption to each room to keep SWMBO happy!



I quite fancy doing something like this, along with perhaps some method to
control garden sprinklers, but am concerened about reliability. If
controlled from say, a ring main, the signals would have to go back to the
CU, through an RCD, meter tails, a switchfuse, 30m armoured cable, and then
another RCD before reaching the module. How does this compare to your
setup? Have you had any reliability issues?

Many thanks,

Chris Key

I quite fancy doing something like this, along with perhaps some method to
control garden sprinklers, but am concerened about reliability. If
controlled from say, a ring main, the signals would have to go back to the
CU, through an RCD, meter tails, a switchfuse, 30m armoured cable, and
then another RCD before reaching the module. How does this compare to
your setup? Have you had any reliability issues?

Many thanks,

Chris Key

Why would the signal need to go over meter tails? Is there a seperate meter
to each building? If so you may be fed from different phases...

My arrangement from X10 computer controller goes: (computer in loft, mains
supplied as spur from upstairs ring main)
Ring CU MCB busbar MCB 30m (ish) SWA cable garage CU main switch
busbar MCB radial circuit in garage X10 module.
Signals travel fine in both directions, if I use an X10 transmitter in the
garage, the computer recieves them fine also.

Alan.

Alan wrote:
I quite fancy doing something like this, along with perhaps some
method to control garden sprinklers, but am concerened about
reliability. If controlled from say, a ring main, the signals would
have to go back to the CU, through an RCD, meter tails, a
switchfuse, 30m armoured cable, and then another RCD before reaching
the module. How does this compare to your setup? Have you had any
reliability issues? Many thanks,

Chris Key

Why would the signal need to go over meter tails? Is there a seperate
meter to each building? If so you may be fed from different phases...

We have the house CU, and two switchfuses (garage / summerhouse) all fed
from a henley block, hence the need for the signals to go via a short length
of meter tail. All comes from the same supply though.

My arrangement from X10 computer controller goes: (computer in loft,
mains supplied as spur from upstairs ring main)
Ring CU MCB busbar MCB 30m (ish) SWA cable garage CU main
switch
busbar MCB radial circuit in garage X10 module.
Signals travel fine in both directions, if I use an X10 transmitter
in the garage, the computer recieves them fine also.

OK sounds fairly similar, with the exception of the two RCDs. Has anyone
had any luck sending X10 through an RCD? Any thoughts on typical inductance
for these, as they'll need to pass 120kHz.

Chris Key

"Christopher Key" wrote in message
...
Alan wrote:
I quite fancy doing something like this, along with perhaps some
method to control garden sprinklers, but am concerened about
reliability. If controlled from say, a ring main, the signals would
have to go back to the CU, through an RCD, meter tails, a
switchfuse, 30m armoured cable, and then another RCD before reaching
the module. How does this compare to your setup? Have you had any
reliability issues? Many thanks,

Chris Key

Why would the signal need to go over meter tails? Is there a seperate
meter to each building? If so you may be fed from different phases...

We have the house CU, and two switchfuses (garage / summerhouse) all fed
from a henley block, hence the need for the signals to go via a short
length of meter tail. All comes from the same supply though.

My arrangement from X10 computer controller goes: (computer in loft,
mains supplied as spur from upstairs ring main)
Ring CU MCB busbar MCB 30m (ish) SWA cable garage CU main
switch
busbar MCB radial circuit in garage X10 module.
Signals travel fine in both directions, if I use an X10 transmitter
in the garage, the computer recieves them fine also.

OK sounds fairly similar, with the exception of the two RCDs. Has anyone
had any luck sending X10 through an RCD? Any thoughts on typical
inductance for these, as they'll need to pass 120kHz.

Chris Key

Yes, I've gone over 2 RCD's also between the split load CU RCD side, and
into the kitchen fed from it's on MRCD(?) on the non-CD side of the CU.
Works fine also.

Alan.

Alan wrote:
Yes, I've gone over 2 RCD's also between the split load CU RCD side,
and into the kitchen fed from it's on MRCD(?) on the non-CD side of
the CU. Works fine also.


Thanks for that, sounds like it'll be fine then. I'll hopefully be able to
give it a go over Easter.

Chris Key