Bathroom Lights

[grimster]

Again, thanks all for the advice.

The coil contacts are the top (not the left) and the switch contacts are at the bottom. The relay is there to prevent the switched live from the downstairs bathroom feeding back into the upstairs lighting circuit and turning the lights on.

This is what was happening when I bought the house (every house in the street is wired in the same crazy way!!). The two bathrooms share a single fan. I cured it by changing the downstairs light switch for a doouble pole switch - (the upstairs one was double pole already) - but now I want to make the upstairs dimmable and you can't get a double pole dimmable pull cord. The relay was just a way of keeping the two circuits seperate.

Is there anyway this would work or am I flogging a dead duck?

 

[ban-all-sheds]

The coil contacts are the top (not the left) and the switch contacts are at the bottom.

So when the dimpull is turned on, the coil windings are in series with the new lights.

This will result in:

1) The new lights not lighting up.

2) If/when the relay contacts close, then if the downstairs light is on and if you've got separate lighting circuits you'll have joined them together.

 

[grimster]

Ban, you are a legend on this forum!

I see the error of my ways regarding the relay in series.

I realise that (assuming this works) the circuits are joined when both upstairs and downstairs lights are turned on and that is probably very bad practice.... but it's no different than it (and all other houses on my street) have been since 1972.

Amended diagram...


PS... My wife wants to know what you have against sheds?

PPS... Just to re-assure you, I will get this will get checked my my qualified spark friend!!

 

[ban-all-sheds]

PS... My wife wants to know what you have against sheds?

As in this:

not this:

 

[ColJack]

a PIR is still your best bet.. no messing about and you then feed the PIR from downstairs so that you don't get interlinking of circuits..

your current idea will still require a 3 core and earth from downstairs to bring permanent live, switched live and neutral up to the fan and relay, so go for the easy option..

as for the PIR getting triggered falsely, put it directly above the door as close to the wall as you can, this cuts down the "viewing" angle of it to nothing more than a few CM outside the door.. and does it really matter if it gets triggered anyway?