Wiring a push-to-break switch with 3 downlights (diagram)

[JohnW2]

Thanks John. I've re-done my diagram based on what I'm interpreting from the posts above. Could I confirm then that the below is a parallel wiring setup and safe?

Yes and yes (the latter obviously assuming that the work is undertaken 'safely').

My first diagram was based on the instruction leaflet: ... However I can't see any reason why it's any different electrically 'daisy-chaining' them vs. using a choc box.

As you say, electrically there is no difference.

Kind Regards,

 

[riveralt]

I've re-done my diagram based on what I'm interpreting from the posts above. Could I confirm then that the below is a parallel wiring setup and safe?

Yes.

However I can't see any reason why it's any different electrically 'daisy-chaining' them vs. using a choc box.

It is just a different way of completing a radial circuit. By adding a jb (chockbox) there are more potential terminal errors which could lead to problems. You would also likely use more cable.
Flipside of 'daisy chaining' is that a bad terminal connection at any of the lights terminal block could result in the lights down line not working.

 

[FoxtrotOscar]

OK cheers guys really appreciate the help.

Whilst I understand that safety is crucial it's nice to be able to ask wiring questions without being bombarded with 'hire a spark' replies.

 

[Jackrae]

Personal opinion only, but that's a really poor design of switch for use on mains voltage. In fact I doubt it meets decent engineering standards for the application (even if it has CE marks on it).

Mains switches should have snap-action mechanisms which that one clearly does not have.

Consider the situation where the switch is just opening and the door that pushes it stops moving. The arc across the contact will be sustained with the result that the switch contacts continue to arc, the plastic melts, catches fire and whatever else ensues.

 

[FoxtrotOscar]

OK, interesting. I searched for a while and there wasn't much choice in terms of push-to-break switches. I don't know much about electrical arcs but will the low current draw make an arcing scenario less likely?

Incidentally this is the switch in question:

http://www.amazon.co.uk/White-Surface-Break-Light-Switch/dp/B00403YI3I

The spring isn't exactly soft; it's fairly stiff so I'll have to make sure the wardrobe doors hinges are adjusted to ensure the door is being shut quite strongly.

 

[JohnW2]

Mains switches should have snap-action mechanisms which that one clearly does not have. Consider the situation where the switch is just opening and the door that pushes it stops moving. The arc across the contact will be sustained with the result that the switch contacts continue to arc, the plastic melts, catches fire and whatever else ensues.

No-one can argue with the concept/theory of what you're saying. However, given that we are talkiing about AC, that the current in the circuit (through arc or otherwise) will be restricted to a low level by the load and the fact that the door position would have to hover around a very critical position for such a problem to be apossibility, I would imagine that the risk is actually extremely small.

There obviously are some ('bare') positive-action non-latching push-to-break switches (many of them microswitches) around, but I don't recall ever having seen one built into a product for domestic lighting use - one would probably have to put it into some sort of enclosure for oneself (that's what I've done for wardrobe light switches etc. in my house).

Kind Regards, John

 

[skotl]

Thanks guys. I didn't appreciate that daisy chaining them such was the same as wiring them in parallel, but looking at efli's diagram it seems obvious now.

I would suggest that you should exercise caution (and ask for clarification if there is any doubt) when anyone talks of 'daisy chaining'. I'm not sure about the rights and wrongs (even most dictionary definitions I've seen don't clearly distingusih between series and parallel connection), but some people use 'daisy chaining' to refer to any situation in which components are wired from one, to another, to another, to another ... (as opposed to each being wired separately from some common point), regardless of whether the components are wired in series or in parallel.

It is pretty rare in (e.g. domestic) electrical installations to have components wired in series, so 'daisy chaining' will, in that context, nearly always mean 'in paralllel' - but I would still suggest that you should always ask for clarification if there is any doubt at all about what someone means by the phrase.

Kind Regards, John

Thanks, John. It was me who originally raised the vague term - I did mean "in parallel", of course and will be sure to be clearer in future.

 

[JohnW2]

Thanks, John. It was me who originally raised the vague term - I did mean "in parallel", of course and will be sure to be clearer in future.

Indeed, and I'm sure that nearly all of us understood that you meant 'in parallel'. However, as I said, it's certainly not 'just you' so I do think that someone with any uncertainties (such as the OP clearly had) should always seek confirmation of the intended meaning of 'daisy chaining' (just as the OP did).

Kind Regards, John

 

[riveralt]

However, as I said, it's certainly not 'just you' so I do think that someone with any uncertainties (such as the OP clearly had) should always seek confirmation of the intended meaning of 'daisy chaining' (just as the OP did).

I'm not sure why you are criticising EFL and others - the diagram he produced was very clear and was acknowledged so by the OP. Whenever the words were used again the OP had a clear and visible reference point.

 

[JohnW2]

I'm not sure why you are criticising EFL and others - the diagram he produced was very clear and was acknowledged so by the OP. Whenever the words were used again the OP had a clear and visible reference point.

Eh? I'm not criticising anyone - merely advising caution. EFLI's diagram was, indeed, very clear. However, "whenever the words are used again", someone who thinks in terms of EFLI's clear diagram could possibly end up with the wrong interpretation, if the person who spoke/wrote those words was (as some certainly do) using the words in a different way. That's all I was saying.

The great majority of us here know that a number of 230V lights need to be wired in parallel, so it doesn't matter to us what words are used. However, in a forum like this, we do need to consider those people who do not necessarily have the same degree of knowledge.

Kind Regards, John

 

[riveralt]

I'm not sure why you are criticising EFL and others - the diagram he produced was very clear and was acknowledged so by the OP. Whenever the words were used again the OP had a clear and visible reference point.

Eh? I'm not criticising anyone - merely advising caution. EFLI's diagram was, indeed, very clear. However, "whenever the words are used again", someone who thinks in terms of EFLI's clear diagram could possibly end up with the wrong interpretation, if the person who spoke/wrote those words was (as some certainly do) using the words in a different way. That's all I was saying.

Don't you see your response is an oxymoron. EFL's diagram clearly outlines the difference between serial and parallel circuits and links the words 'daisy chaining' to the appropriate circuit.
Remember the OP at the outset raised the issue

Regarding daisy chaining them, I was under the impression that that would be the same as wiring them in series, which I thought was a no-no for this type of light. Also the instructions show them wired in parallel like that. Very happy to be corrected on that though, cause it'd mean one less junction box.

EFL then produced his diagram and the OP's response was:

Thanks guys. I didn't appreciate that daisy chaining them such was the same as wiring them in parallel, but looking at efli's diagram it seems obvious now..

So the OP has a clear image of what parallel wiring (daisy chaining) is and even goes further by producing the diagram indicating the assimilation of that knowledge.

Other than yourself, of those who posted after EFL's diagram, who has caused any confusion?

 

[JohnW2]

Don't you see your response is an oxymoron. EFL's diagram clearly outlines the difference between serial and parallel circuits and links the words 'daisy chaining' to the appropriate circuit.

No. EFLI's diagram clearly links the words 'daisy chaining' to one of the two circuits (which is the appropriate one in this case) but, as I keep saying, the OP may find other people using 'daisy chaining' to refer to the other (series) circuit.

So the OP has a clear image of what parallel wiring (daisy chaining) is ...

.. but, again, you are asserting, just as EFLI implied, that 'daisy chaining' always equates to parallel wiring. You don't have to look very far to find examples of the words 'daisy chaining' being used to refer to series connection. For example (the first example my Google search found), this 'factsheet' contains the statement:

If a number of LEDs are connected to a voltage source along a single path (i.e. in daisy chain fashion), this is called a series connection.

Hence my view that one should exercise caution when interpreting the words 'daisy chaining' when one comes across them.

Kind Regards, John

 

[JohnW2]

Other than yourself, of those who posted after EFL's diagram, who has caused any confusion?

Whatever confusion you may think thas subsequently arisen (when you started taking me to task for my 'caution' message, after the OP had thanked me for it), I don't think anyone could deny that I gave the OP very clear and non-confusing confirmation/advice when (before you replied to his same message) I wrote:

Thanks John. I've re-done my diagram based on what I'm interpreting from the posts above. Could I confirm then that the below is a parallel wiring setup and safe?

Yes and yes (the latter obviously assuming that the work is undertaken 'safely').

My first diagram was based on the instruction leaflet: ... However I can't see any reason why it's any different electrically 'daisy-chaining' them vs. using a choc box.

As you say, electrically there is no difference.

Kind Regards, John

 

[bernardgreen]

Mains switches should have snap-action mechanisms which that one clearly does not have..

I totally agree with that. The risk of prolonged arcing at the contacts when the door is opened or closed slowly is high and the consequential risk of overheating is high.

 

[Jackrae]

Obviously most of you guys have never made or never seen a real daisy chain.

It is the technique of linking the flower known as DAISIES together into a CHAIN to form a garland or head-band such as shown here http://www.google.co.uk/imgres?imgu...fob-UZagEo6V0QXg74AQ&ved=0CF8Q9QEwAw&dur=2249

To use the term to refer to circuits connected in parallel is clearly the creation of confusion (and possibly danger) whereby misuse becomes practice which becomes procedure.

Daisy-chaining circuits should only ever be considered as circuits connected in series.

Circuits connected in parallel may be considered as "multi-drop" but I'm sure others will correct me.