Intermediate wiring

[Asm]

I was at college last week and overheard a conversation of someone who had that day been doing the installation part of their AM2 and by all accounts there has been a few small changes to the AM2 since January.

They said the the wiring of the intermediate lighting circuit in PVC/PVC has changed and now has to be wired:
-twin & earth feed to the first 2 way switch
-3 core & Earth from the first 2 way to the intermediate switch
-3 core & earth from the intermediate to the second 2 way switch
-twin & earth from the second 2 way to the luminaire

I've been thinking about it and can't come up with a way to connect that and it work, am I being stupid or have I overheard **** information.

 

[Darkwood]

If in doubt try draw it out, this way it will stick in your head. Try drawing out a 2way as suggested without the intermediate first then it should be easier to add the intermediate.

 

[Leesparkykent]

You wont have a neutral at the end switch.

 

[davesparks]

I was at college last week and overheard a conversation of someone who had that day been doing the installation part of their AM2 and by all accounts there has been a few small changes to the AM2 since January.

They said the the wiring of the intermediate lighting circuit in PVC/PVC has changed and now has to be wired:
-twin & earth feed to the first 2 way switch
-3 core & Earth from the first 2 way to the intermediate switch
-3 core & earth from the intermediate to the second 2 way switch
-twin & earth from the second 2 way to the luminaire

I've been thinking about it and can't come up with a way to connect that and it work, am I being stupid or have I overheard **** information.

Simples, you use a standard two way switching circuit and carry the neutral through on the extra core.
So the live feed goes to the common of the first switch, two strappers are taken from there to the intermediate and then on to the last switch, the common of the last switch is the switched live.
The neutral just joins through on the extra core at each point.

 

[Asm]

But isn't it still a core short for the neutral?

 

[Asm]

Simples, you use a standard two way switching circuit and carry the neutral through on the extra core.
So the live feed goes to the common of the first switch, two strappers are taken from there to the intermediate and then on to the last switch, the common of the last switch is the switched live.
The neutral just joins through on the extra core at each point.

ahhh yes, I get you. Simple really, I was being stupid.

 

[telectrix]

not if you're only using 2 cores for strappers instead of the conventional 3, where there is no neutrals required at the switches.

 

[davesparks]

not if you're only using 2 cores for strappers instead of the conventional 3, where there is no neutrals required at the switches.

Eh? There's only two strappers however you wire it?

 

[telectrix]

i tend to call the link from common to common ( joined at intermediate) a strapper. for want of a better word to describe it. if there is one i'venever heasrd it.

 

[davesparks]

i tend to call the link from common to common ( joined at intermediate) a strapper. for want of a better word to describe it. if there is one i'venever heasrd it.

Common is a pretty good word for it, I doubt there is a proper term as it's an adaptation of a conventional 2way circuit.
I think it's better to stick to established terms and definitions of them when discussing things with trainees.

 

[telectrix]

agreed, but it does seem a bit silly to refer to a 3 core cable as strappers and common.