Re: LW10u - won't turn off ?

[Keith Doxey <ukha@xxxxxxx>]

Quoting Marcus Warrington <marcusw@xxxxxxx>:

> I just bought and installed an LW10u switch. It works fine as a
> local switch but won't turn OFF via X10 unless I (locally) dim
> the light to about 50%. Its using a 100Watt bulb and will turn
> on fine via the HR10u/TW12u just not off. Given that the main reason
> for fitting it was to make sure the light was turned OFF during
> the day, its slightly annoying to say the least... and SWMBO can't
> see why I've spent £30 on an "ugly" light switch.
>
> Can anyone explain to me why I'm seeing this behaviour ?
>

Hi Marcus,

Possible explanation....

The LW10 only connects to the Live and SwitchedLive wires so to get power
for
its own operation it relies on a small voltage drop across the switch when
it
is on to obtain enough power to operate. This is also how it receives its
X10
signals so the lower the drop across the switch, the lower the signal
level.

Its possible that when the light is on at 100% there is insufficient
voltage
for the signal amplifier to operate properly or that the signal is just too
weak. The Local control operates the chip directly so wouldnt be affected
by
that. By dimming the light, you are creating a greater voltage drop across
the
switch thereby giving it more power to operate with and also increasing the
signal level to it.

I am assuming that you can turn it on by X10 with no problems. If not then
you
have a general problems with X10 signal strength.  The signal level is
probably
quite low in that area of the house and it is just on the border line of
operating anyway.

My house had been relatively free of X10 problems for almost 6 years but
having
moved my Laserjet4, added a new PC, and re-arranged some other kit, I now
have
problems with X10.

HomeVision no longer "sees" the X10 transmissions from the IR543
in the lounge
although both HV and the IR543 can control the lights in the lounge.

Homevision can control the DIN rail module in the kitchen for the Hot Water
Heater but for the last 3 weeks cannot control the Appliance module
connected
to the kettle apart from last weekend when it succeeded in turning it off.

I need to dig out some filters that I have to see if I can isolate all the
PC
and AV gear from soaking up the X10 signals.

Try putting a 200W load on the switch to see if you can then turn it off
remotely when it is set to 100%, if you can then it would indicate that it
needs more power to operate or more signal.

Another thing you can try is to unplug ALL TV sets, Computer Equipment, all
appliances fitted with motors, and anything else that has a switch mode
power
supply. If it then works perfectly it will indicate that something in the
house
is soaking up the X10 signal and needs to be filtered.

Start plugging stuff back in until it stops working but BEWARE... it may
not be
any single item causing the problem, it could be the cumalative effect of
several devices. If you have all your PC equipment fed via a distribution
board
then a single X10 filter on the input to that will effectively isolate all
the
gear from the mains wiring.

If you have a "FILTERED POWERSTRIP" for anything eg HiFi or PC
equipment, note
that the filter is designed to kill interference on the mains side which
means
that it will kil X10 dead.

Hope that helps

Keith