Is this Intermediate switching image from the Student's Guide wrong?

[rewireIT]

Shouldn't the lines from the first switch both go into the L1 L2 on the intermediate switch?

 

[James]

Looks correct to me.
but feel free to draw out your solution for comparison

 

[rewireIT]

Looks correct to me.
but feel free to draw out your solution for comparison

Ok so on that note, the reason i'm asking is because the GSH electrical channel has a video on this, and he says the L1 L2 from the first switch cannot go L1 L3 and must go L1 L2 on the intermediate switch.

Is he wrong or is that just another way of doing it?

 

[timhoward]

What GSH was probably meaning is that you need to connect to the left hand side of the the switches as marked in fig 8.14
If you connect to the top two terminals as marked in fig 8.14 then things won't work as intended.

In real life it's never not been the top two grouped and the bottom two grouped as far as I can remember.

 

[nicebutdim]

Guide does appear to be poorly illustrated. If wired as per 2nd image the circuit would only ever close with intermediate in one position.

I'm not sure if all intermediate switches are marked L1-L4 but, as @timhoward states, the general convention is that they're intended to receive one set of strappers in the top and the other in the bottom.

 

[davesparks]

Ok so on that note, the reason i'm asking is because the GSH electrical channel has a video on this, and he says the L1 L2 from the first switch cannot go L1 L3 and must go L1 L2 on the intermediate switch.

Is he wrong or is that just another way of doing it?

Different manufacturers label switches in different ways so they are both right for a particular brand and style of labelling.

The diagram in the book is correct for the way the switch is shown as operating in the picture above it.
The GSH video is correct for the majority of common switch manufacturers, but not all.

The key thing is to learn how the circuit works and how to read the manufacturers instructions/diagrams.

Anyone can match wires to numbers, an electrician needs to understand what they are doing.

 

[davesparks]

I'm not sure if all intermediate switches are marked L1-L4

I've seen them with two pairs of L1 and L2 and with A1, A2, B1, B2

 

[timhoward]

Guide does appear to be poorly illustrated.

AH I see the issue now. Yes. I was looking at the whole circuit which is ok.

The picture top right in fig 8.14 is not consistent with the diagrams showing how the switches work. At least that is my experience.
Ignore the picture of the real switch.

 

[nicebutdim]

I've seen them with two pairs of L1 and L2 and with A1, A2, B1, B2

I wasn't going to make any bold statements were labelling of intermediate switches was concerned as it's not something I've studied in great detail - that and the fact that switches seem to be labelled as and how each manufacturer sees fit.

Thinking about this some more, I think L1, L2, L1, L2 is probably what I've seen most often. After this thread I'm going to find myself studying ever single intermediate switch that crosses my path

 

[rewireIT]

I'm still rather confused as to what you're all saying - so is it the picture of the 'real' switch that is wrong physically, or is it labelled wrong?

The real switch picture and the diagram are laid out the same, so which part is wrong?

 

[rewireIT]

If wired as per 2nd image the circuit would only ever close with intermediate in one position.

I've traced it and it looks like it would operate normally?

 

[nicebutdim]

I'm still rather confused as to what you're all saying - so is it the picture of the 'real' switch that is wrong physically, or is it labelled wrong?

The real switch picture and the diagram are laid out the same, so which part is wrong?

Look at the switching arrangement shown in the first image. I've never seen an intermediate switch configured in that way, but it is correct for wiring in second image.

I've traced it and it looks like it would operate normally?

It will operate normally according to images shown, but would not operate normally according to the top-bottom convention that appears to have given rise to this thread.

 

[davesparks]

I'm still rather confused as to what you're all saying -

Not all intermediate switches are labelled in the same way, different manufacturers have their own conventions on labelling the same as they do with normal 2 way switches.

so is it the picture of the 'real' switch that is wrong physically, or is it labelled wrong?

It is unconventional for an intermediate switch to work that way but the circuit shown is correct for the wiring diagram of the switch.

 

[davesparks]

I've traced it and it looks like it would operate normally?

Yes, the circuit as drawn matches the wiring diagram as drawn and will operate correctly.

in the real world the majority of intermediate switches would require one pair of strappers connected to L1&L2 and the other pair of strappers to L3&L4.

 

[rewireIT]

Not all intermediate switches are labelled in the same way, different manufacturers have their own conventions on labelling the same as they do with normal 2 way switches.

It is unconventional for an intermediate switch to work that way but the circuit shown is correct for the wiring diagram of the switch.

I get ya i think - so the top left image of how it switches is unconventional? What does it normally look like? I want to learn the common way which is applied to most switches and now feel like i can't really trust the guide i bought.

I mean i get how it's working in terms of the wiring, but it was GSH's comment here that completely threw me since he makes it sound like a rule.

 

[nicebutdim]

I get ya i think - so the top left image of how it switches is unconventional? What does it normally look like? I want to learn the common way which is applied to most switches and now feel like i can't really trust the guide i bought.

I mean i get how it's working in terms of the wiring, but it was GSH's comment here that completely threw me since he makes it sound like a rule.

I've never seen a switch that was configured for anything other than one cable in top terminals and other in the bottom, but that's not to say other arrangements don't exist and there's no reason why they shouldn't.

The guide you have has shown everything correctly, albeit in what could be considered an unconventional manner. It's worth remembering that exams are similarly devised, with questions intended to determine whether a candidate is paying attention, and understanding what is in front of them, or simply repeating mantras they've been taught.

 

[snowhead]

The intermediate in the GSH video is shown changing over differently to the one in the first post on this thread,
so his statement is correct for his switch / drawing.

 

[rewireIT]

The intermediate in the GSH video is shown changing over differently to the one in the first post on this thread,
so his statement is correct for his switch / drawing.

View attachment 109502

But would this be the normal way most switches would do it? Is the guide i'm using (IET Students Guide to the Wiring Regs) using an uncommon switching pattern to demonstrate an intermediate switch?

 

[Taylortwocities]

The wiring isn't done like that for the (common) loop in at lamp method. In fact, the student diagram is from wiring that was done a very long time ago.......

 

[nicebutdim]

The wiring isn't done like that for the (common) loop in at lamp method. In fact, the student diagram is from wiring that was done a very long time ago.......

A lot of loop in wiring is done in exactly this manner in NI and for good reason. I'm of the opinion it's important that students learn this method as it will be very common outside of domestic installations in GB.