Neon indicator for 3-way garage lights

[Andy Burns]

the right hand switch?

[Richard Russell]

That's right. It's possible the OP may need to swap a 2-way switch with an intermediate switch to achieve the correct arrangement.

The more general topology of the N-way 'alternative' method is (simplified):

2-way switch Any number of intermediate switches Load(s) Neon(s) Any number of intermediate switches 2-way switch

So for example it's possible to have more than one switch in the house as well as more than one in the garage, with loads in both places, without any extra wiring. It's just a case of ensuring that the leg to which the load(s) and any monitoring neons are connected is the leg which joins the house to the garage.

I've never understood why this 'alternative' method isn't more popular. The Wikipedia article says it "can cause confusion" but, come on, it's only wires and switches - you don't need a PhD to understand it!

Richard.

[Andy Burns]

What about the 'carter' method?

I can see it's more dangerous where ES lamp-holders are prevalent, but is it outlawed or frowned-on over here with BC lamp-holders? Not many people would be expecting both prongs to be live when it was switched off ...

[Richard Russell]

It also has rather unfortunate consequences if the switches are make-before-break!

Richard.

[The Medway Handyman]

Drill a hole in the door & insert a door viewer.

[Dave Liquorice]

"across" connection mode.

It was late last night and I was tired. B-)

Doesn't work if you connect the load to the RH switches L1 or L2 which i= s what I had last night by simply inserting an IM switch between the chang= e overs.

With three switches the load has to be on the other side of the "supply"= change over switch. With four or more switches the load can be any where= except on the last change over switch. I think...

[Richard Russell]

In the general case there is a 2-way switch at each end with any number of intermediate switches in between. You can connect the load(s) and supply to any leg, including the end ones (my drawing shows the load and supply connected at the left-hand end). But the load must be connected to the same leg as the supply!

One way to think about it is that a changeover switch plus any number of intermediate switches is equivalent to a single changeover switch. This allows you to expand the basic topology as shown on Wikipedia by adding intermediate switches at either end:

Changeover switch (plus any number of intermediate switches) load(s) + supply Changeover switch (plus any number of intermediate switches)

Richard.

[Andy Wade]

Even with break-before-make there is the distinct possibility of an arc propagating and causing the same consequences - especially if the load is inductively-ballasted discharge lighting.

[Andy Wade]

For UK wiring in twin- and triple-&-earth cable the alternative method (as it used to be called) *is* standard. A 'switch-drop' T&E cable from a ceiling rose or luminaire goes to one 2-way switch. From that switch you run 3&E cable via zero or more intermediate switches to a second

2-way switch.

The other method (formerly called standard) is appropriate when wiring with singles in conduit.

[Richard Russell]

It's probably worth noting that the 'switch drop' doesn't have to go to one of the 2-way switches, it can equally well go to any of the intermediate legs (i.e. between two intermediate switches). This gives a lot of flexibility and can reduce wiring lengths.

If as you say this method is now standard perhaps it's how the OP's setup is wired, in which case the most he might have to change to fit his neon is to ensure that the 'switch drop' connects to the leg which runs from the house to the garage.

Richard.

[Harry Bloomfield]

Bob Minchin formulated on Saturday :

I have a similar arrangement in place, for PIR controlled lighting, except instead of wiring a neon across the output I used a piezo sounder. The output of the transformer just generates a few volts, only enough for the sounder, so perfectly safe and the noise is difficult to miss.

[newshound]

+1 !

[Harry Bloomfield]

Richard Russell was thinking very hard :

before.

[Paul G]

Thanks for the suggestions & comments. The switch in the house is an intermediate but nearby (inside the garage) is the switch with live & switched live. So I've been able to lay another cable from this garage switch to the switch in the house, with a view to using an MK K3041 Neon Switch Locator, or MK Gridswitch with an neon indicator. Am I correct in thinking I need to use both wires of this new cable rather than just the neutral ?

Thanks Paul

[Dave Plowman (News)]

Yes - you need to get the live feed from the end of the two way circuit. So effectively make the neon like an extra fitting on that circuit.

[Bill Wright]

In my experience people with a PhD are no more likely to understand electrical installation than anyone else.

Bill

[The Natural Philosopher]

Especially in anthropology

[Harry Bloomfield]

Those words you quoted were not written by me, they were written by Richard Russell.