The 'carter' Wiring Method

[SLIPSHOD & SLAPDASH]

Whilst on holiday in Canada my brother found some work for me to do in his house (typical).  I did some research and found an old and now banned 2 way switching method known as the Carter method that was commonly used there & the US.

Note they call the live or phase 'Hot' & show the connected cables as red & non-connected as black. They also call 2 way switching 3 way.



How dangerous, depending on which end is switched you are breaking the live or the neutral & reversing the polarity across the lamp. Only ES lamps are used so the outer exposed connection could be live. No wonder its banned. I found this method disconnected in my brothers car port.

Another interesting 2 way switching circuit is called the California method which seems a good idea. You always have a live, neutral & switch line at all points in the circuit. This would need 4 cores plus an earth but you could add a light anywhere on the circuit.



Their regs  are all 2 (3) way switching has to have all cores inc the neutral carried in the same cable. Different electrical licenses & regs apply to domestic, industrial etc.

 

[ProDave]

The Californian method is not that different to what we often do, though it's usual for the perm L in and switched L out to come from the same switch.

That would not work if you introduce an intermediate switch in the middle though (would not work as in you could no longer add a light from any point)

So to comply with their regs you would need 4 core & E cable? I assume that must be available over there.

I do like the neutral carried around with the L strappers.  That's easy to do here with 3 core & e and I do it often.  I'll see if I can do a quick drawing.  

Drawing attached

2 way with neutral.pdf

 

[binky]

known as 'conduit method' down ere in Devon

 

[SLIPSHOD & SLAPDASH]

Its very unusual for the conduit method to have the neutral running with the strappers.

I was taught the live into the common one end then 2 strappers between switches and the switch line to the common the other end was the 'conventional' conduit way using the lest amount of cable.

A 3c & e between switches with a Tw & e across the strapper's at one switch is the 'conversion' method  using the least amount of cables in domestic work.

The 'California' method of having the live on one strapper one end and  the other strapper the far end is something i have not seen before.

For your info the Canadians and Americans refer to the strappers as 'The travelers'

 

[davetheglitz]

Perhaps we should call it the 'let some other con do it' method!

Thanks or the Carter method - explaining how it works and why it is dangerous should be a good question for my students.

 

[binky]

don't confuse Rob again, the lad struggles to tie his shoelaces as it is! :slap

 

[davetheglitz]

There's a new market - steel toe cap loafers!

 

[binky]

that'll be rigger boots.