On 2 Oct 2004 "robert horsey" wrote:

I have a single switch down which controls a light near the front
door it also can be switched on or of by a double switch upstairs at
the moment if you have the upstairs switch in one position you cant
switch the light on or off.

What do you mean by this? Is the light permanently off or permanently
on, or as I interpret your description, does it stay in whatever state
it was set to by the downstairs switch when you put the upstairs switch
in this position? I find this somewhat difficult to believe.

It's more likely that you have connected one of the wires from the
light to the common terminal instead of one of the other two. That way
if either switch is in the on position you won't be able to turn the
light off using the other switch.

I also have another single switch down stairs which controls the
light at the top of the stairs. that is also controlled by the
double switch upstairs with that one the light only comes on by
using the down stairs switch.

I'm beginning to think that you may have cross-wired the two sections of
the double switch upstairs, or that one of the wires is not connected or
one switch is duff. I'd be inclined to take the switches off, suss out
what does what if the terminals aren't clearly marked and start again.

this all came about when I tried to replace the switches. before I
started I wrote down the way the switches were wired but I seem to
have gone wrong somewhere . Is there some where I can get a wiring
diagram or can someone explain where I have gone wrong

It should be straightforward. Both switches are connected by a triple
core (+ earth) cable. Make sure you connect C to C, L1 to L1 and L2 to
L2. C is the common terminal which is connected by the switch to either
L1 or L2. If the switch isn't marked then test it with a circuit tester
or multimeter or lamp and battery (when it's not connected to the
mains of course). Never mind what physical positions the wires were in
before because switch designs vary.

At one of the switches - probably the downstairs switch for the
downstairs light and the upstairs switch for the upstairs light - there
will also be a two core (+ earth) cable. This should be connected to L1
and L2, not C.

I'm not sure what the regs say but on the triple core cable I use red
for the live side, connected to red on the twin, blue for the load side,
connected to black on the twin, and yellow between the commons.

All earth wires, if provided, should be sleeved and terminated on the
wall boxes. If there's an earth terminal on the switch (if it has a
metal face plate) this should also be connected.

The way it operates is that if the common wire is connected to live at
one switch and load (the lamp) at the other switch then the lamp is on;
if common is connected to the same side on both switches the lamp is off.

--
Richard Porter
Mail to username ricp at domain minijem.plus.com
"You can't have Windows without pains."