NEWBOY NEEDS HELP, 2 WAY HALL/LANDING SWITCH.

[JONNIGEE]

Hi I've previously posted on here, and basically I've taken the advice that I was given, but the light is still not working. I have bought a new metal 2 way light switch for the downstairs hallway, it services the hall light and the upstairs landing light. I need to know how to correctly wire the new switch because the B&Q instructions are gibberish. I have got two red wires and two black wires coming out of two thick grey wires in the housing backplate. The switch has two rectangular wiring blocks which sit side by side, they both have a screw housing marked 'L' at the top and each block has two screw holes at the bottom of the block marked 'L1' and 'L2'. I have wired red to 'L' and black to 'L1' (as previously advised) the downstairs light then works but the upstairs won't. I can turn the upstairs light on and off using the upstairs switch but the new downstairs switch is ineffective. Can somebody please let me know how to wire this switch so I can operate both lights. thanks very much.

 

[Spark123]

How is the upstairs switch wired? How was the downstairs one wired before?
If you can upload some photos this will help

 

[ban-all-sheds]

1) How was the old switch wired?

2) Do you understand the various ways in which 2-way switching circuits work?

3) Do you own, and know how to use, a multimeter?

4) In what way are the B&Q instructions "gibberish"?

too quickly

Doh!

 

[holmslaw]

..

 

[ban-all-sheds]

Or even worse, he didn't used to have....

 

[Spark123]

The shared neutral scenario seems viable however I'm thinking how does it still work from the upstairs switch?
I can think of one way of it working however it will involve a shared neutral in the hallway light (unless they are both on the same circuit).

 

[sealeon]

It is normal that a downstairs passage light would be on the same circuit as the upstairs passage light to avoid two circuits being fed from two different fuses at the switch and therefore having a potential of 400 volts at the switch.

 

[Spark123]

Wouldn't you need to have a 3 phase (or 2 phase) supply for that to happen?

 

[sealeon]

It was always what we were taught we always had to put labels inside the switches whwn we come across them.Its pretty dangerous to have two circuits in same switch in a domestic I think

 

[BS3036]

That because you might turn off one circuit, but not the other, because you don't realise there are two different circuits there. Usually only talking about 230V because british houses usually only have one phase. Of course in germany the circuits are evenly spread across all 3 phases, so the 400V warning would be appropriate.

 

[holmslaw]

..

 

[sealeon]

Still think its safer not to have two circuits in a switch in a domestic reg or no reg and best to have landing and downstairs passage on same circuit if usimg a two gang switch

 

[securespark]

I have just skim-read this, so apologies if I am talking rubbish.

If you have only two twin & earths at the switch, they must be wired like this:

One pair is the live feed and switchwire for the 1 way light, the other are the strappers.

Therefore, the live feeds both commons, the switchwire from the "live" cable goes to L1 on one side and the strappers go to L1 & L2 on the other.

However, you need a two-pole voltage & continuity tester to bell out the wiring so you know which pair is which.

 

[Newboy1996]

Newboy does not need help, I am just fine!

Newboy1996