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Topic Title: Hello everyone
Topic Summary: After some advice on a Double Pole 2 Way switch
Created On: 02 November 2017 12:09 PM
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 02 November 2017 12:09 PM
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nickhalluk

Posts: 5
Joined: 02 November 2017

Hi all,

Had a bit of a search but couldn't fine any answers.

I'm designing some lighting for a house and need some Double Pole 2-Way light switches, but they don't seem to be a thing. Has anyone come across any or have suggestions on a work around.

Essentially I want 2, 2 Way light circuits, but at the location were they both have a switch I don't want a 2 gang socket, I want a 1 gang so using a Double Pole 2-Way (DPDT) would give me this.

Thanks,
Nick
 02 November 2017 12:40 PM
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dustydazzler

Posts: 1447
Joined: 19 January 2016

Why do you need neutral disconnection on a lighting circuit ?

I personally have never come across a double pole two way switch
 02 November 2017 12:47 PM
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AJJewsbury

Posts: 15997
Joined: 13 August 2003

No never seen such a thing (at least not in a conventional UK switch plate version - I've see plenty DPDT switches available for equipment though).

The only thing that comes to mind is something like a wide rocker switch with exchangable (grid like) switch modules - you might get two to operate from the same wide rocker (I'm thinking of MK masterseal swicthes, but I guess you'd want something less industrial). Other than that it would be a conventional switch and a DPDT relay hidden away somewhere - but that's perhaps not ideal.

Are you sure you really want one switch to 'flip" both 2-way "circuits"? I can see that if you're in say a corridor it might be convenient to turn both on at the same time, but if one was already one (switched from the far end) you could only get the other on by turning that on off - which feels unhelpful. The more usual solution is either a 2Gang 2Way switch (on a 1-gang faceplace) or have a 3-way switching system for all the lights together (i.e. 2-way switches at each end and a 4-terminal intermediate switch in the middle).

Or go continental and use retractive switches (as many as you like, all wired in parallel) and a step relay.

- Andy.
 02 November 2017 12:49 PM
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AJJewsbury

Posts: 15997
Joined: 13 August 2003

Why do you need neutral disconnection on a lighting circuit ?

My guess was that the OP wanted to operate two 2-way switches simultaneously - so switching L twice rather than N.
- Andy.
 02 November 2017 01:20 PM
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broadgage

Posts: 2433
Joined: 07 August 2007

Double pole 2 way switches for industrial control panels and the like are readily available, but I have not seen one in a domestic light switch format.

As has already been said, a suitable relay operated from a single pole switch is one possibility.
If a re-purposed or slightly modified witch is acceptable, look for a NOS MK logic 2 gang 2 way switch, or very close equivalent.
This type has the two switch rockers adjacent without a gap between them. Cut a small piece of rigid plastic to neatly cover both switch rockers and fix with suitable adhesive.
You now have in effect a 2 pole 2 way switch as the two single switches operate together.

I have installed triple pole 2 way switches for external lighting where it was desired to switch three lighting circuits together from both the main building and a remote security post.
In this case industrial switches were fine.
 02 November 2017 01:35 PM
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nickhalluk

Posts: 5
Joined: 02 November 2017

Thanks for all the input, I'll try and explain what I'm trying to achieve.

There is a Kitchen/Diner with 4 banks of lights lets say A, B, C and D.

AB light the Diner
CD light the Kitchen
BC light the Breakfast Bar

There are several entrances to the room hence the 2-Way requirement..(but only some light will be controllable at some entrances)

I could just control each bank with its own switch, but that would be to easy, I'd like to control each grouping with one switch (in reality one 2-way circulate)

I've mapped out the circuits and they work on paper, the hardware just doesn't exist to support it.

All suggestions are very welcome
 02 November 2017 01:59 PM
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Martynduerden

Posts: 3235
Joined: 13 July 2008

Use a lighting controller and programmable retractive switches, loads of options when you move away from twin & earth / singles at switches.

Lutron
Loxone
ZWave

To name but a few

-------------------------
Regards

Martyn.

Only a mediocre person is always at their best
 02 November 2017 02:05 PM
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dustydazzler

Posts: 1447
Joined: 19 January 2016

As above , install an intelligent lighting system
 02 November 2017 02:29 PM
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AJJewsbury

Posts: 15997
Joined: 13 August 2003

There is a Kitchen/Diner with 4 banks of lights lets say A, B, C and D.

AB light the Diner
CD light the Kitchen
BC light the Breakfast Bar

There are several entrances to the room hence the 2-Way requirement..(but only some light will be controllable at some entrances)

I could just control each bank with its own switch, but that would be to easy, I'd like to control each grouping with one switch (in reality one 2-way circulate)

I've mapped out the circuits and they work on paper, the hardware just doesn't exist to support it.

All suggestions are very welcome

I think we need a bit more detail about what you're trying to achieve. As you describe it the 'breakfast bar' banks are controlled by 2 separate sets of switching - e.g. if you switched on 'Kitchen' and then 'Diner' presumably you'd expect both breakfast bar banks to be on too (without switching any of the 'breakfast bar' switches). If the Kitchen switches were 'on' and the Dining ones 'off' (so half the breakfats bar lights were now on and half off) what would you expect operating one of the 'breakfast bar' switches would do? Turn on the ones that are off? Turn off the ones that are on? of both? (I suspect simple 2-way switching will do the latter - which is probably the least helpful).

If you want the breakfast bar lights on when either of the kitchen or diner is in use (or both) then perhaps you just need two switching systems - one for kitchen directly controlling bank D, one for the diner directly controlling bank A, and banks B & C switched by a pair of contactors wired in parallel so they come on when either (or both) of the set of switches are "on".

Or just re-arrange your lights into three banks...

- Andy.
 02 November 2017 02:29 PM
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nickhalluk

Posts: 5
Joined: 02 November 2017

Like the idea of a Smart light system, but not the price. the relay idea seems like it has legs, but it's not something I'm familiar with. can anyone give me a steer?
 02 November 2017 02:49 PM
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nickhalluk

Posts: 5
Joined: 02 November 2017

@AJJewsbury you're correct in your assumed behaviour:

If Kitchen lights (C and D) are On the Breakfast Bar switch would only turn on/off bank B but if kitchen is off it would operate bank B and C
Same for Diner and Breakfast Bar combination.
If both Kitchen and Diner are On Breakfast Bar switch would do nothing.

Lighting designers have specified 8 lights (4 banks of 2) to get the lighting level requirements. I could just have 4 switches, but like I said that would be easy.

Trying to work out how the contactors would work.
 02 November 2017 02:54 PM
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sparkingchip

Posts: 10100
Joined: 18 January 2003

If I remember it correctly in part L of the domestic Building Regulations there is a line that says "A single switch should normally operate no more than six internal light fittings with a maximum total load of 100 circuit-watts."

Andy B
 02 November 2017 03:05 PM
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AJJewsbury

Posts: 15997
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Trying to work out how the contactors would work.

A contactor (or relay) is just a switch controlled by an electromagnet (coil) - a relay might have any kind of contacts (normally open, normally closed, change-over and several poles, while by convention a contactor just has normally open contacts (and usually fairly high rated ones).

So 2-way switching bank "Kitchen" controls the kitchen-only lights directly plus the coil of contactor "X".
2-way switching bank "Diner" controls the diner-only lights directly plus the coil of contactor "Y".

Both contactors have a pair of normally open (make) contacts (which close when the coil is energised) - wire the contacts of the two contactors together in parallel and use to control the middle two banks of lighting. In effect you've created an OR-gate between the two switches to control the two middle banks of lights.

(You can also achieve the same using one change-over relay controlled by just one of the switch bank, but that's slightly more difficult to describe!)

- Andy.
 02 November 2017 03:18 PM
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mapj1

Posts: 9557
Joined: 22 July 2004

I'm not really sure why you cant have a 2 gang intermediate switch at each location, as it seems that at each point door 2 different zones converge. After all, when you come in through a mid door and flick the switch you may not want to have to turn off the kitchen lights off to your left to put the breakfast lights on to your right- I think your original single switch rocker proposal has this weakness.
(or if you never want kitchen on and breakfast off or vice-versa, then you only really have one big circuit)

-------------------------
regards Mike
 02 November 2017 03:20 PM
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nickhalluk

Posts: 5
Joined: 02 November 2017

Thanks Andy. Think I follow. it appears to be "working" in my head, just need to draw it out.

How/where can I mount the contactors? do you have any links to suitable hardware?
 02 November 2017 06:40 PM
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AJJewsbury

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Joined: 13 August 2003

Just examples (there are many different brands and prices out there) -

contactor: http://www.tlc-direct.co.uk/Products/HGESC225.html

enclosure: http://www.tlc-direct.co.uk/Products/BHCT4.html

(personally I'd go for a 4-module rather than 2-module enclosure for two contactors - not only gives you a bit more wiring space but allows a bit more room for airflow as contactors can run warm after a while). If it's going to be somewhere that isn't dry and clean then go for a decent IP rated one with a lid instead.

The contactors are MCB sized so will usually fit into just about any modular enclosure - even your consumer unit if you have a few spare ways (and if the bus-bar doesn't get in the way).

- Andy.
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