Problem with 3 way lighting

I've just bough a house and only just noticed that there are 3 light's all of which should be able to be turned on or off from 3 different switches, not independantly but on of off all together. However at times one switch doesn't seem to be able to turn them on whilst the other 2 switches work. At other times one of these switches won't work and the other 2 will work. Any ideas what could be the problem. All the lights work, it's just that the 3 swiches don't work together

Reply to
waqaaz
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I've just bough a house and only just noticed that there are 3 light's all of which should be able to be turned on or off from 3 different switches, not independantly but on of off all together. However at times one switch doesn't seem to be able to turn them on whilst the other 2 switches work. At other times one of these switches won't work and the other 2 will work. Any ideas what could be the problem. All the lights work, it's just that the 3 swiches don't work together

Reply to
waqaaz

It sounds like there`s a little crossed wiring in there - are you confident enough to slacken the screws on all the light switches to see how they`re connected ?

Excuse the crap ascii attempt, but IIRC these are the two main ways of connecting 2-way lighting circuits, the first being the most common

_______ ________ mains __/ \/ \__ light \_______/\________/ 3way intermediate 3way

mains __________ ________ /.......\/........\ /_____ note the dotted line is connected light __\_______/\________/ \ straight through 3way intermediate 3way

You`ll notice in the second example you need a 3 core cable between switches

Reply to
Colin Wilson

How about this one?

L1 L1 0===========0 0===========0============= Line | \ / | C 0================================O C \ / \ / 0===========0 0===========0============= Switch return L2 Optional L2 Intermediate

Reply to
Dave Plowman (News)

One of the switches isn't an "intermediate". You'll need to work out what wires go between which switches and the lighting loop and the fittings. This might not be easy. The circuit is simple but implementing it with twin and earth or three core and earth is fun and variable...

(Fixed pitch font required)

o------o o------o +--- bulb ---+ / \ | | L ---o \ o----+--- bulb ---+--- N \ / | | o------o o------o +--- bulb ---+ S1 S2 S3

S1 and S3 are single pole change over switches. S2 is the "intermediate" it connects one corner to the diagonally opposite corner at a time.

Reply to
Dave Liquorice

No t'isn't. In your circuit, if you reverse S3 then the light can

*never* be on regardless of the position of S1, without also operating S2.

Intermediate switch is a straight-through or swap of the strapping wires, ie. = or X

ie (light on)

o------o o------o / \ / / \/ o----+--- bulb ---+--- N L--o /\ / / \ / o------o o------o

S1 S2 S3

or (light off)

o------o---o-------o / / o----+--- bulb ---+--- N L--o / / o------o---o-------o

S1 S2 S3

Owain

Reply to
Owain

Oh dear; time to become pedantic ..... when you write 'at times' and 'at other times', do you mean to say 'intermittently'? Or is the behaviour of the switches and lights combinations consistent (but just not what you expect)? if 'at times' = 'sometimes it does, sometimes it doesn't': there _might_ be a loose wire. Perhaps you could supply a 'Truth Table' (it's a valid engineers' tool, honest) which will give the states of the switches and lights - it'll look something like this;-

SW Light

A B C A B C O O O O O O O O 1 O 1 O ( for instance) ......

I I I I I I

There are only eight possible combinations for the switch positions; On = I, Off =O and eight possible 'states' for the lights On = I, Off = O: so it shouldn't take too long to 'catch' the data - then one might be able to discern the desing and/or intent.

Reply to
Brian Sharrock

On 8 May 2006 11:38:44 -0700 someone who may be " snipped-for-privacy@googlemail.com" wrote this:-

Standard multiple switching. It should work fine.

Without rather more information how will anyone know? Are "at times" and "at other times" related to the phases of the moon, the price of fish, or something less exotic? As has been suggested, do a simple experiment and tell us whether there are certain switch positions when it doesn't work as it should, or the times it doesn't work are random.

If there are certain switch positions then it is likely to be one or more of the switches. Either one or more is wonky, or the wrong sort of switch is installed, or (perhaps) the wiring is wrong.

If the times it doesn't work are random then it is either wiring not connected properly, or an switch with an intermittent fault.

If you know what you are doing, then it might be worth bypassing the intermediate switch and checking that the resulting two-way switching works properly. If it does then you have isolated the fault. The intermediate switch is the one with four connections.

Intermediate switches are relatively rare, but MK make them as part of their Gridswitch range and I assume other manufacturers do as well.

Reply to
David Hansen

You need to think a bit harder.

And that scheme results in exactly the OPs problem, that not all switches are able to control the lights, depending on the state of the other switches.

Start with the switches in the positions shown by your diagram and the light is on. Operate the intermediate and the light turns off. Neither S1 nor S3 are now able to turn the light on.

MBQ

Reply to
manatbandq

There is probably a miswiring problem, here is a link for diagrams: -

formatting link

Reply to
John McLean

Thats a joke right ?

Dave

Reply to
gort

Presumably, since most of the sheds sell ordinary plate switch intermediates. Grid types are useful if you want a two or more gang with one or more intermediates, though. Don't think I've ever seen a two gang intermediate plate switch on sale.

Reply to
Dave Plowman (News)

On Tue, 09 May 2006 14:04:56 +0100 someone who may be gort wrote this:-

No. Why do you think it is.

Reply to
David Hansen

On Tue, 09 May 2006 14:59:21 +0100 someone who may be "Dave Plowman (News)" wrote this:-

Can't say I have ever noticed any. However, I have not been looking.

Reply to
David Hansen

T'was late after a long day, 4+hrs driving and 11hrs on camera.

Ta, I knew one needed an intermediate and how it should be wired. Just got the detail of the intermediates innards wrong. I've never had to use one so not had the opertunity to play and find out what they realy do.

Thank you for supplying the correct information, unlike others who just criticise.

Reply to
Dave Liquorice

Because if I went to my electrical wholesaler and he said that, I would tell him to stop pissing around. Have a look in B&Q next time your near one.

Dave

Reply to
gort

It's just a double pole changeover with the commons not accessible.

Reply to
Dave Plowman (News)

On Tue, 09 May 2006 18:29:45 +0100 someone who may be gort wrote this:-

You assume that I have not. However, as I said in another posting, "Can't say I have ever noticed any. However, I have not been looking."

I didn't notice any on the MK web site either, other than as Gridswitch components.

Reply to
David Hansen

MK K4875 is the Logic Plus part number. And pretty well all other makers do them too.

Reply to
Dave Plowman (News)

On Wed, 10 May 2006 01:13:19 +0100 someone who may be "Dave Plowman (News)" wrote this:-

I'll have to try harder if I ever want one.

Reply to
David Hansen

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