Top and Bottom Stairs 2-Way Switches not working correctly

[ban-all-sheds]

I don't either, what's wrong with using t&e in a 2 way switching situation?

It can cause EMI.

It's not recommended if you have a choice.

 

[333rocky333]

theres nothing wrong, but you would need a LIVE at one switch and the SWITCHLINE at the other, which the OP does not have, he has both SWITCHLINE and LIVE at the same switch, with the other switch paralleled off it.

 

[John D v2.0]

Oh, how does it compare with a normal switching situation with L and SL? I know using 3+e can cause induction between the two adjacent cores, but I didn't realise that about emi, as it's still just 50hz mains.

 

[ban-all-sheds]

theres nothing wrong, but you would need a LIVE at one switch and the SWITCHLINE at the other, which the OP does not have, he has both SWITCHLINE and LIVE at the same switch, with the other switch paralleled off it.

True - 'fraid I got derailed by the argument about using 2 cores for strappers.

 

[endecotp]

I didn't realise that about emi, as it's still just 50hz mains.

The 50 Hz is an issue mainly for interfering with HiFi and hearing aids. You would probably also get harmonics in the audio range.
I don't think high frequency EMI will tend to radiate from that sort of loop.

 

[mwatsonxx]

I agreed with Watson

Are you drunk, you've agreed with me, how will you ever live it down.

 

[ban-all-sheds]

Unlike some people, I am not so stupid that I believe in ad hominem attacks.

 

[ban-all-sheds]

I didn't realise that about emi, as it's still just 50hz mains.

EMI is electromagnetic interference - can be any frequency.

 

[John D v2.0]

Sorry my point about emi is I don't see what's special about using t&e that could make it worse. I'm aware you'll get some radiation from any live conductor but I don't see what the specific core usage is that would be a problem with t&e.

 

[EFLImpudence]

The point is whether you have two adjacent conductors cancelling each other or a single loop.

 

[John D v2.0]

The point is whether you have two adjacent conductors cancelling each other or a single loop.

What conductors would be classed as cancelling from an emi point of view? I assume neutral, but short of running the neutral and live together and switching both I can't see a solution.

3+e can actually have other problems if it's wired wrong for example capacitance between live and switched live or different Strappers.

 

[EFLImpudence]

Two lives in opposite directions has the same effect - is the same - as live and neutral.

 

[John D v2.0]

Good point about the lives in different directions - so based on that wiring 2 way switches with t&e would be as good as 3&e. And seems you need to connect the live and the load at the same "end" in either case.

 

[EFLImpudence]

so based on that wiring 2 way switches with t&e would be as good as 3&e.

No, because you only have single conductors.

And seems you need to connect the live and the load at the same "end" in either case.

You would (the switch drop) but you can't have two-way switches with T&E as the strappers - the case in this thread.

I shall re post my diagram - follow the current

 

[ianniann]

Not only EMI, but also there is a distinct likelihood of having live and neutral taken from different circuits.