dundee 2 way? anyone help!?

[The apprentice]

theres a link from the connector of the earth to the back box just cant see it in picture

 

[telectrix]

theres a link from the connector of the earth to the back box just cant see it in picture

yes but the metal faceplate is more critical than the back box. either earth the faceplate/s instead or link to back box with a fly lead.

 

[Andrew Hunter]

Well said Andy 78 was about to jump on the ex-potential bonding of the face plate my self there.
that looks to me like some one has used a three gang intermediate (middle of a three way) switch plate with 2 of the switches wired correct as intermediate and the third wrongly wired as a two way.
again would help if switch wires identified as clearly there are neutral's present in this switch plate box.

 

[Richard Burns]

Hmm, based on some of what has been described (particularly the massive joint box) and from viewing the photos I might assume he has "simply" wired two three way switches and a single one way switch with the connections from all switches (excluding the one way switch) collected in a central joint box, from which the lights are also supplied.
Therefore each two way switch for both sets of three way switching would have a single 3 core cable to it, the intermediates pictured have two 2 core to each switch, as shown.
The one way switch looks like it might just be basic switch fed lighting: loop in and out (L and N) at the switch and run the switched line and neutral to the light.
Possibly looking like this (though I have got this picture wrong several times so may not be right now)! I am sure it will make things clear as crystal!

I have not heard it called Dundee wiring though, perhaps Dumb Dee wiring?

 

[ipf]

Think he might be having you on...…..return bus ticket to Dundee, maybe

 

[davesparks]

I don’t know that I would call your standard method ‘standard’, at least not now.
It’s this method which causes borrowed neutrals when used on stair lighting.

How on earth does it cause borrowed neutrals? I've installed a lot of 2 way circuits this way and it's never caused a borrowed neutral to appear in my wiring?

The cause of borrowed neutrals is people wiring things incorrectly through lack of knowledge, care or just plain stupidity.

 

[pirate]

Like the cake...it's all down to currant carrying capacity

 

[Deleted member 26818]

How on earth does it cause borrowed neutrals? I've installed a lot of 2 way circuits this way and it's never caused a borrowed neutral to appear in my wiring?

The cause of borrowed neutrals is people wiring things incorrectly through lack of knowledge, care or just plain stupidity.

If you take the feed to the downstairs light switch from the downstairs lighting circuit, then feed the upstairs light from the upstairs light switch, where do get the neutral for that upstairs light?

 

[davesparks]

If you take the feed to the downstairs light switch from the downstairs lighting circuit, then feed the upstairs light from the upstairs light switch, where do get the neutral for that upstairs light?

Obviously the neutral has to come from the same circuit as the feed, there's no question about that. In your scenario you'd either run a single neutral or a 3 core between switches then twin from upstairs switch to the light.

Always select the method of wiring the 2 way which suits the particular installation best.

 

[Lucien Nunes]

I think it would be more true to say that the 'conventional' arrangement with PL at the downstairs switch and SL upstairs, offers a 'temptation' to borrow the line from the downstairs circuit, that many used to find hard to resist. The neutral at the light is the one that would have been used anyway.

One advantage of the 'switch conversion' method (PL and SL paralleled with strappers) is that there can be no open space within current loops to radiate interference from dimmers, LED drivers etc. With the conventional system, if the PL takes one route to the switch, the strapper takes another to the other switch and the SL another to the light, a large loop can be formed that radiates quite badly. I did this with some florries, and when switched on you could not listen to an AM radio anywhere near the circuit due to the buzz. Rewiring it to the 'switch conversion' method shut it up.

I wonder what names have been given to these schemes in various places. In the US, what has been called the 'switch conversion' scheme above, is 'California 3-way', and there was also the 'Carter 3-way' which has been prohibited both in the US and UK since the 20s, with the switches each sending L or N to one lamp terminal.

 

[telectrix]

think what spin is referring to is when the L for the landing light is taken from the downstairs as in a 2 gang switch for hall (1 way) and (2 way) for landing, with the L linked between the commons. was done regularly in 60's and 70's . we'd not do this today, but back then, it was accepted, along with wind-up meggers and bang tests. loop impedance was how long an apprentice could hold onto 500V from the megger before screaming for his mum.

 

[Lucien Nunes]

Yes that's what I mean Tel, we always call it a borrowed neutral but in this case it's really the line that's borrowed from the downstairs 1-way.

 

[coolsparx]

I quite like jobs to fix lights where everything has been disconnected. The more wires the better, especially if some connections don't belong in the standard rose terminal blocks.

One of the best ones I had to fix was the switching for a light in another room that (for historical reasons) went via the rose in a different room. And a smoke alarm installer adding a wireless room alarm had mistaken the blue (old colours 3-core) for N. The light in the other room then never turned off completely.

I had one the other day, the home owner was changing a bathroom light & thought it would be wired the same as one in another bathroom, apparently the light came on, then went bang when he pulled the switch. It was a bit of a head scratching challenge for me as there were 2 twin & earth cables ;-)

 

[dksanders]

this is what he had.
he had a 3 gang toggle switch. this is the wires he had at it 3 x 3 core into the first switch he had 1 x 2 core and 1 x 3 core into the second switch in the 3rd toggle he had 3 x 2 core doing 3 no of lights had a feed in and linked them all joint all neutral at switch dunno how he done go get him to draw it on a bit paper tomorow to let use all see

Do you know what commas and full stops are?

 

[vjsmarwick]

There used to be a company up here that ran all lighting wires back to a 6x6 box and wired everything from there ! What a mess and many a time bedroom switches would be switching lounge lights or bathroom lights and sometimes some lights wouldn’t switch off at all ! I much prefer looping mains at the switches !