AM2 Lighting

[YoungBart]

Hi all, I do apologise if this has been posted before, But I'll be damned If I can find it. I have my AM2 this week, and I'm fairly confident In all aspects of it (Famous last words). But I've just hit a snag while trying to work out the lighting.
Apparently the circuit is a 2 way and intermediate, wired in 1.5 t&e, with the feed going to the switch. (I can manage that bit)
and the strappers and switch wire are all ok, But what about the Neutral, I've just seen somewhere that says I need another legnth of cable between the first 2 way switch and the last 2 way switch with the Brown unused (in a connector) and the neutral Joining up with the feed Neutral and the Neutral from the light (again in connectors).
Anyway I've done a quick diagram (of sorts) does it look ok to you (from a technical point of view NOT artistically)

 

[murray2707]

How about feed and neutral into first switch, switch and neutral back to light from first switch. Then just a 3core t&e from first switch, with com joint through in intermediate switch to your last switch.

 

[Guest55]

im afraid your wiring layout is completely wrong young man.

it can be done using just a single 3 core & earth cable which will carry the neutral through the switches and onto the light.
the problem is you've taken the permanent live ( brown ) to all the switches when it should go no further than the common terminal in switch 1




it should be like above but with the neutral going through the switches on its way to the light.

 

[trebor]

I would say you have been looking at the ----------- website which is probably the cause of so many failures, take note of murray2707, far more accurate

 

[YoungBart]

Murray, I'm fairly sure the spec for the AM2 says the feed into one switch and the switch wire out of another switch, So unfortunately that is not an option. Biff I tried to draw my diagram using the info, from sparky facts (As trebor has said) website, And upon further investigation I have misread it, and shouldn't have continued my brown feed.

 

[trebor]

The spec says I can assure you 150% the feed from the db to sw1 next to the db, a 3 core and earth from sw1 via the intermediate to sw 3, the twin and eaearth fom the light back to switch 1, hence you will have two twin and earths in the first switch, screwless connectors must be used to marshall the neutrals and cpc`s, the common in the intermediate and also the lone cpc in switch 3, eg wagos

 

[YoungBart]

Thanks Trebor, I've evidently been fed duff information from the 'Sparky Facts' I've been focusing that much on the S plan that the Lighting has falled down the pecking order

 

[trebor]

youre welcome, by the way the common is grey, and dont forget to brown sleeve the grey and black in all switches

 

[KAS1]

How about loop in loop out system, T&E down to SW1 3c&E SW1-SW2 and 3c&E SW2-SW3 all done without the need for N at switch in this case as not necessary

How about feed and neutral into first switch, switch and neutral back to light from first switch. Then just a 3core t&e from first switch, with com joint through in intermediate switch to your last switch.

 

[Guest55]

How about loop in loop out system, T&E down to SW1 3c&E SW1-SW2 and 3c&E SW2-SW3 all done without the need for N at switch in this case as not necessary

its a requirement of the am2 exam to do it a particular way KAS , they wont have option to choose the 3 or so different ways of wiring the circuit.

 

[Garythenab]

im afraid your wiring layout is completely wrong young man.

it can be done using just a single 3 core & earth cable which will carry the neutral through the switches and onto the light.
the problem is you've taken the permanent live ( brown ) to all the switches when it should go no further than the common terminal in switch 1


View attachment 18975

it should be like above but with the neutral going through the switches on its way to the light.

Yep agree with with that. Thats how it was done when i done it 1 1/2 years ago

 

[YoungBart]

Ok, So a day to go and my nerves are rattling like crazy, I can barely hold my glass of scotch lol. I've got these 2 methods for my lighting, Can anyone tell me if they are both correct (They should all be functional) and wich of the two methods is best.

 

[Guest55]

no 1 is correct , no 2 isnt.

 

[KAS1]

If you draw the switch positions in, as in biff's drawing you'll be able to follow the diagram and determine as to why the switching works or doesn't, it's the easiest way.

 

[YoungBart]

The 2nd method is just what I could decipher from a message a friend sent me, so possibly he's got confused or I've missed a point a copy of the message 'the feed in goes in the bottom of switch (L1) and the feed to the light from (L2) of same switch then strappers as normal between switches terminal block on common at intermediate tho I think your way works aswell there is no need for the connector in the first switch you just make use of the switch terminals instead if u do it my way plus that's how I did it and I passed...eventually!! '

I can see now with the switching paths that it won't work.
Just wondering if my 1st method will be ok with it having 2 connectors at the first switch (Neutral, SL+C, CPC)

 

[ackbarthestar]

From what I can see, youngbart, both of your drawings are correct, that is, both will work.
The easiest one is to grasp is your top drawing and probably the one to remember

The top one is an adaption of a two plate wiring system and the bottom one is an adaption of of a three plate wiring system.

Now whether it is acceptable to use a 2-plate method in T&E or whether it acceptable to take a neutral down to the switch for a 2-plate method are open to debate.

However, if you are still in doubt I would draw out 16 little diagrams, tedious I know, but you'll have a handy reference for the future.

 

[somersetsparks]

I thought they used singles for the lighting on the AM2? how times change, T+e for everything now :-(

 

[ackbarthestar]

I thought they used singles for the lighting on the AM2? how times change, T+e for everything now :-(

If its conduit wiring then it should be by convention 2-plate wiring.
If i remember rightly, there is both T&E and singles used on the AM2. I can't remember whether or not they use T&E for the lighting though.

 

[Hants-Spark]

If its conduit wiring then it should be by convention 2-plate wiring.
If i remember rightly, there is both T&E and singles used on the AM2. I can't remember whether or not they use T&E for the lighting though.

It was singles when I done mine some 25yrs ago but they never told you how it was to be wired you could do it however you wanted, 2 or 3 plate.

 

[somersetsparks]

It was singles when I done mine some 25yrs ago but they never told you how it was to be wired you could do it however you wanted, 2 or 3 plate.

Same when I done mine 5 years ago, seem to remember it had a landlords override switch as well.

 

[Hants-Spark]

Same when I done mine 5 years ago, seem to remember it had a landlords override switch as well.

Possibly but I dont have that good a memory I'm afraid lol, I mainly remember having to wire a nurse call system as one of the modules, safe to say I was panicing but lucky enough I got it to work, more luck than judgement I think lol

 

[YoungBart]

It's all in twin now, got my results back and I failed the install, something on the ring circuit and something on the lighting, all tested and worked fine so not really sure what was wrong.

 

[Hants-Spark]

It's all in twin now, got my results back and I failed the install, something on the ring circuit and something on the lighting, all tested and worked fine so not really sure what was wrong.

Gutted for you mate, chin up though and I'm sure you'll pass the resit. Good Luck

 

[KAS1]

In practice how many conduit systems would you wire in singles as a 3 plate ???

It was singles when I done mine some 25yrs ago but they never told you how it was to be wired you could do it however you wanted, 2 or 3 plate.

 

[Outspoken]

The spec says I can assure you 150% the feed from the db to sw1 next to the db, a 3 core and earth from sw1 via the intermediate to sw 3, the twin and eaearth fom the light back to switch 1, hence you will have two twin and earths in the first switch, screwless connectors must be used to marshall the neutrals and cpc`s, the common in the intermediate and also the lone cpc in switch 3, eg wagos

That is bad practice unless there is absolutely no choice, neutrals should not be in switches.

Feed goes from MCB to Light, from light a T&E to Switch 1 (2 Way), from Switch 1 take a 3C & E to Switch 2 (Intermediate) and then another from this switch to Switch 3 (2 way). You just have to ensure you connect it correctly...

Job DONE

 

[Outspoken]

Have to agree with many of the comments here, if you are wiring lights in conduit, then 2 plate is the preferred method. With T&E or structured cable installs then the preferred method is more often 3 plate as you do not end up with neutrals and joints in switches.

 

[markc123]

It's all in twin now, got my results back and I failed the install, something on the ring circuit and something on the lighting, all tested and worked fine so not really sure what was wrong.

Unlucky buddy, you'll get there in the end - have a never say die attitude and turn up next time even more determined. Being from Bridlington, are you doing it in Hull by any chance? i did mine there years ago.

Your installation was probably correct, worked perfectly and tested out bob-on. However, if you haven't followed there instructions then you'll fail even if your way is better than theres. The AM2 test is also about being able to follow orders, which you'll have to do on site whether it's from the architect or your boss. Read the instructions very carefully. Best of luck.

 

[ackbarthestar]

It's all in twin now, got my results back and I failed the install, something on the ring circuit and something on the lighting, all tested and worked fine so not really sure what was wrong.

My sympathies, Youngbart, its a real barsteward when things go pear shaped when you thing all has went well.

I think its now standard practice to get some feedback about your efforts, so it would be well to ask why they failed you.

Its always good to have some redirection so you don't make the same mistakes again....

 

[Hants-Spark]

In practice how many conduit systems would you wire in singles as a 3 plate ???

In practice probably none, but just saying at the time they never stated the method which it was to be wired, therefore it was your choice.

 

[YoungBart]

Unlucky buddy, you'll get there in the end - have a never say die attitude and turn up next time even more determined. Being from Bridlington, are you doing it in Hull by any chance? i did mine there years ago.

Your installation was probably correct, worked perfectly and tested out bob-on. However, if you haven't followed there instructions then you'll fail even if your way is better than theres. The AM2 test is also about being able to follow orders, which you'll have to do on site whether it's from the architect or your boss. Read the instructions very carefully. Best of luck.

Yes doing mine Hull, given the state of some if the accessories I probably used the same gear as you did! I think I know what I've done wrong in the lighting, and it's just a case of I mis read the drawing and fed the furthest switch instead of the nearest one,

will definitely ring them to find out what I've ballsed up on my ring circuit though. Just noticed I have to re do my fault finding as well. I got a fault on the motor which stumped me, so I probably got that wrong.

 

[Engineer54]

Have to agree with many of the comments here, if you are wiring lights in conduit, then 2 plate is the preferred method. With T&E or structured cable installs then the preferred method is more often 3 plate as you do not end up with neutrals and joints in switches.

Now wait for those that will come out and say ''I always loop through the switches'' for all my lighting circuits, saves me working on a step ladder and getting sore arms!! lol!! :sad_smile:

 

[Knobhead]

 

[KAS1]

If I came across this method of wiring I'd think "What a chancer" who the ***** taught you that method should be shot lol

 

[Knobhead]

If I came across this method of wiring I'd think "What a chancer" who the ***** taught you that method should be shot lol

Nobody taught me that method, I worked it out in less than a minute and drew it out.

I’ve spent my life in industrial, not house bashing!

 

[KAS1]

You and me both, but you certainly would not contemplate that as a "house bashers method" whatever next...........

Nobody taught me that method, I worked it out in less than a minute and drew it out.

I’ve spent my life in industrial, not house bashing!

 

[telectrix]

If I came across this method of wiring I'd think "What a chancer" who the ***** taught you that method should be shot lol

that's exactly how i've just drawn it. using brow/black for strappers and grey ( slevved blue) for N.

 

[ackbarthestar]

Nice diagram, Tony. From the look of it you are the culprit who can't be bothered to use a ladder then?

Some chap i used to work with said there are 27 variations of wiring for two way lighting circuits. I think I've come across about 10 of them, lol....

 

[Knobhead]

Nice diagram, Tony. From the look of it you are the culprit who can't be bothered to use a ladder then?

Some chap i used to work with said there are 27 variations of wiring for two way lighting circuits. I think I've come across about 10 of them, lol....

Did I say I'd do it like that? Read the OP.

 

[Guest55]

neutrals should not be in switches.

utter crap lol.
;-)

 

[Engineer54]

utter crap lol.
;-)

It's not utter crap at all!! ..lol!! :nono:

 

[Guest55]

oh it really really is lol.
been on any UK commercial contracts lately E54 ?

 

[Engineer54]

Well, if they are now pulling neutrals through switch boxes for no reason, i don't think i'd want to be associated with them!! Though i doubt very much that on any prestige projects, you would see that method of wiring, especially if it's an all metal containment system, which you would expect on a prestige project anyway!!

 

[Guest55]

im not talking about singles in conduit Eng , im talking about lighting circuits , both domestic & commercial that are wired in T&E ( as per the OP's discription ) as its common practice to loop in / out at the switch carrying the neutral through.

 

[Engineer54]

Not in my world it's not!! Not unless a neutral is required at a switch, then fine!! But looping/jointing neutrals at every switch, No Way!! And i don't care if it's acceptable or not with BS7671....

 

[Marvo]

I guess it's just different common practices in different geographical locations, neutrals jointed in switches is common practice here. I have nothing against it electrically and more and more switches nowadays require a neutral for small illuminating led's or neons in the switch itself. I can't ever remember having a fault caused by neutrals being jointed and it can also make for easy future extending of the light circuit if necessary.

 

[Guest55]

Not in my world it's not!! Not unless a neutral is required at a switch, then fine!! But looping/jointing neutrals at every switch, No Way!! And i don't care if it's acceptable or not with BS7671....

thats because in your world materials get delivered to jobs by rickshaws or junks lol.
;-)

- - - Updated - - -

I guess it's just different common practices in different geographical locations, neutrals jointed in switches is common practice here. I have nothing against it electrically and more and more switches nowadays require a neutral for small illuminating led's or neons in the switch itself. I can't ever remember having a fault caused by neutrals being jointed and it can also make for easy future extending of the light circuit if necessary.

hear hear !
;-)

 

[Engineer54]

I guess it's just different common practices in different geographical locations, neutrals jointed in switches is common practice here. I have nothing against it electrically and more and more switches nowadays require a neutral for small illuminating led's or neons in the switch itself. I can't ever remember having a fault caused by neutrals being jointed and it can also make for easy future extending of the light circuit if necessary.

Same in Cyprus Marvo, my house is all looped through the switches, where the majority of the conduits are laid in the floor screed. In other words, the ceiling conduit systems are not interlinked between the rooms as would be the case in the UK. Most installs in the UK with T&E, would be via ceiling voids etc, so every switch would require at least two cables when using a switch looping system. Back boxes can start getting pretty full when talking about up/down stairs 2 way switch positions!! Nothing against a neutral at a switch position, if it's there for a purpose, but i certainly wouldn't loop through switches as a wiring system. It has to use more cable too, than a UK conventional/typical 3 plate wiring system!!

 

[Outspoken]

utter crap lol.
;-)

That comment is UTTER CRAP Bif, I said that Neutral should not be in switches unless there is not choice...if you have an indicator in the switch, then of course you need a neutral, otherwise, in my opinion, it is a bad practice. The more this type of practice is deemed to be acceptable the more standards lower. I do know that on many job I control if anyone took a neutral to a switch without a darned good reason they would be getting that on the snag list to rewire it at their cost.

 

[KAS1]

Well said they'd be "down the road" on my jobs

 

[jc-electrical]

Thought I'd post my thoughts about the Neutrals at switches debate as this is something I raised with my tutor when doing 2391. He said it is acceptable but not preferred, I raised the point that surely it is better to have the neutral connected in an easily accessible switch than at a (very often inaccessible) junction box as so often the modern fittings do not have the room/facility to properly 3plate the feed and neutrals therefore requiring a JB.