Lighting Circuit Nuetrals in Domestic Light Switches

[Barrie Patrick]

Its been many years since I passed my Apprenticeship and was active on the tools and although a little rusty, (the last training I did was a familiarisation course and an Inspection & Testing Course when the 17th Edition of the IEE Regs replaced the 16th Edition, 1988?) I think I am still a decent Electrician and good Tradesman so can still tell whats right and wrong but as so much has changed in the industry there can always be a little doubt in the back of your mind and I would like a couple of questions confirming?

I recently went to my Neices birthday party at their new house and one of my nephews said the 2 way lighting on the upstairs landing wasn't working and could I have a quick look rather than get myy neices friends, girlfriends brother, who had changed their Consumer Unit and wired up their garage to come again and sort it, I had a look and quickly found it was wrongly connected making 1 switch master to the other so I put it right. My neice was that proud of her new home she showed me round, we went to the garage and alarm bells started to go off, it has 3 lights controlled from a 2 gang light switch by the door, the lighting is wired in white 1.5mm 3 core and earth badly clipped with unevenly spaced clips of varying types and sizes and the switch box is very deep, looks crap but not necesarily unsafe, however there are 4 individual 3 core cables hanging down the wall unclipped and going into the switch box. I took off the cover and in the back were connectors for the 4 nuetrals (black) and 4 earths (Green/Yellow sleeved), the browns were the live feed in, loop to the next room that was built in the back of the garage and the 2 switch wires and the greys had all been cut off, so I took off the switch in the little room and the nuetral was also wired through the switch.

I looked at the Consumer Unit and it looked nicely done but no notices or circuit information given, only the ring main cables for downstairs were to short and the cables had been extended using proper joint boxes fixed to the wall underneath the new CU However no evidance of testing.

My questions are, and I already know the answer:

1) Its not in accordance with the BS 7671 or good practice to wire nuetrals through a switch, unless a double pole switch is used and certainly bad practice to use a connector pushed into the back of the box for the nuetrals and earth?

2) Lighting should be wired using the 3 plate system, no nuetrals at switches?

3) Under the Building regs the work is notifiable and the whole installation should be tested?

Barrie

 

[Darkwood]

Welcome to the forum barrie

 

[telectrix]

there.s nowt wrong with neutals blocked at switches. tbh, i think you are out of your depth hre.andthe 16th did not come into effect till 1991. the 17th in 2008.

 

[DPG]

Common thing now neutral in switches, and much better than trying to cram god knows how many wires into a crappy light fitting whilst on a stepladder. Where do you think BS7671 says it is wrong? Daz

 

[Farmelectrics]

welcome to the forumn

 

[Barrie Patrick]

Hi Telectrix,
Firstly, thank you for taking the trouble to let me know that it is now permisable to wire nuetrals through light switches, personally i think its a retrograde step but I do know things have changed since I was last employed as an Electrician so I thank you and bow to your more up to date knowledge. During my working life I have always had an open mind and been willing to learn new things, as I think we all should, thats why I sought advice from others here who I believe are more up to date and qualified. I also thank you for correcting me on the dates when various editions of the IEE/IET Regs came into force, Barrie

 

[Barrie Patrick]

Hi DPG,
Thank you for taking the time to answer my question about neutrals in light switches, as already mentioned in a previous reply I personally think its a retrograde step to bring neutrals into a light switch box and through connect them to a connector taped and pushed into the back but things do change and we can all learn something new and I stand corrected. In regards to cramming God knows how many wires into a crappy light fitting while on a step ladder I'd say " please dont use crappy light fittings and plan the wiring so you dont have too many wires at one lighting point" LOL

I think if you saw the example I mentioned in my original post of 4 x 3 core and earth cables going into a much deeper box than would be necessary had 2 x twin and earth or 1 x 3 core and earth been run using the 3 plate lighting meathod you might think working off a step ladder was not so bad?

Barrie

 

[Midwest]

My questions are, and I already know the answer:

1) Its not in accordance with the BS 7671 or good practice to wire nuetrals through a switch, unless a double pole switch is used and certainly bad practice to use a connector pushed into the back of the box for the nuetrals and earth?

2) Lighting should be wired using the 3 plate system, no nuetrals at switches?

3) Under the Building regs the work is notifiable and the whole installation should be tested?

Barrie

1) Nought wrong with neutrals at switches, why would there be? Nought wrong with terminating them (and earths) in suitable connectors in said back boxes
2) What ever is a suitable design, for the luminaires installed.
3) New circuits, consumer units & alteration/additions in Zones 1&2 in special location, are notifiable to LBC

What were your answers to your questions?

 

[Midwest]

Hi Barrie. A good example of not using the '3 plate' method, would be when installing downlights. That would involve taking a live/neutral to the switch. The method you speak of, is still used, but as I said before the design of the circuit is adapted to the type of luminaires installed.

 

[Barrie Patrick]

Hi Again DPG,

Sorry I forgot to mention in my first reply to your answer, where/why I thought the 17th Ed (BS7671) might state its wrong to run neutrals through light switches, the truth is I dont know if it does but when my new copy arrives I'll look, hense why I asked here.

However I do recall when studying at Matthew Boulton Tech for my Cert b C&G in the early 1970s we were taught it was wrong, unfortunately I dont own a copy of the 14th ed any more so cannot qoute the reg.

Yes that was the 14th Edition of the IEE Regs LOL Dont worry I have used the 15th and 16th Editions and know there is something called the 17th LOL

Barrie

 

[Midwest]

Hi Barrie. A good example of not using the '3 plate' method, would be when installing downlights. That would involve taking a live/neutral to the switch. The method you speak of, is still used, but as I said before the design of the circuit is adapted to the type of luminaires installed.

That said your description of how the lighting circuits have been installed in your nieces garage, sounds like bit of a dogs dinner.

 

[Barrie Patrick]

Hi Midwest,
Thank you for taking the time to reply to my post. My answers to the questions I posed are/were,
1) Nuetrals shouldn't be run through lighting switch boxes or terminated there, I say this because back in the days of himself and the 12 apostles when I was learning my trade it was not allowed and also considered bad practice, but I do understand things change hense why I asked here.
2) Although I've always used 3 plate meathod when using twin and earth for lighting I do know and have indeed used variations as the need has required (suitable design) but always taken care never to put a neutral in a switch box, now I know its permisable its something I would consider if ever called upon to design and install a lighting circuit.
3) I would have said exactly the same as you, I got this from the guides I bought for Electricians and Inspection and testing.

I know my knowledge is out of date and as i now have lots of free time I am considering paying to go back to college to up date my knowledge and qualifications, even though I'll probably never use them in a commercial sense again............. To Old to be competative LOL

Barrie

 

[Barrie Patrick]

Hi Again Midwest,

I have installed some down lighting fited with cold running LED's in my kitchen and utility room and downstairs toilet using the existing 3 plate lighting system, I just used a junction box to create the lighting point in each room then looped the switched live and perminant neutral and earth (cpc) from light to light, it all went in very nicely.............. Please dont tell me there is now a Reg that says I should have switched the neutral LOL

Barrie

 

[Barrie Patrick]

Hi Midwest,

I think 'Dog Dinner' sums up what I felt when I first saw it :-9

As I said I do realise my knowledge is probably out of date but I do now and always have enjoyed being an Electrician and even though I'm now "Old and Wrinkly and retired2 I do think I'd like to go back and take a couple of courses to bring me back up to date, especially testing and Inspection ;-)

Barrie

 

[Midwest]

[QUOTE
3) I would have said exactly the same as you, I got this from the guides I bought for Electricians and Inspection and testing.


Barrie[/QUOTE] Sounds like your niece may have the same issues as this gentleman found with his mothers newly installed CU. Long thread, but worth a look; http://www.electriciansforums.co.uk...paperwork-new-consumer-unit-installation.html

 

[Deleted member 72666]

Hi Again Midwest,

I have installed some down lighting fited with cold running LED's in my kitchen and utility room and downstairs toilet using the existing 3 plate lighting system, I just used a junction box to create the lighting point in each room then looped the switched live and perminant neutral and earth (cpc) from light to light, it all went in very nicely.............. Please dont tell me there is now a Reg that says I should have switched the neutral LOL

Barrie

....No, but there is a reg(526.3) that states all joint/junction boxes need to be accessible or be of the maintenance free type! Are yours? Oh, and welcome to the forum.

 

[Flanders]

....No, but there is a reg(526.3) that states all joint/junction boxes need to be accessible or be of the maintenance free type! Are yours? Oh, and welcome to the forum.

If you use a maintenance free junction box it does not need to be accessible Hager White 32A Maintenance Free Junction Box, J803 - The Electrical Guys

 

[Deleted member 72666]

If you use a maintenance free junction box it does not need to be accessible Hager White 32A Maintenance Free Junction Box, J803 - The Electrical Guys

Aye, I stated that!

 

[Flanders]

Sorry Did not read your post properly :1eye:

 

[Clive P]

Hi,

I can see where you are coming from Barrie, when I did my apprenticeship I would of been slated if I had run neutrals through switches ; it was a definite No No. Same as running any circuit through a DB, but times have changed especially with the advent of downlights ( we only ever had pendants or florries back in the day). I have been doing some work on my place on the upstairs lighting and I still use the old JB04 method, not everyone's cup of tea; but does it for me.

Regards.

 

[7029 dave]

Hi,

I can see where you are coming from Barrie, when I did my apprenticeship I would of been slated if I had run neutrals through switches ; it was a definite No No. Same as running any circuit through a DB, but times have changed especially with the advent of downlights ( we only ever had pendants or florries back in the day). I have been doing some work on my place on the upstairs lighting and I still use the old JB04 method, not everyone's cup of tea; but does it for me.

Regards.

Yep, times have changed , not going to go into it because N's in switch's have been flogged to death on here.

 

[Clive P]

Hi Dave,

Totally agree, and I now accept neutrals in switches etc; even do it myself!

Regards.

 

[Barrie Patrick]

Hi MidWest,

Thanks for that. I actually read it, well virtually all of it, last night. Bit of a learning curve here for me at present as I've never actually had to deal with building regs before in respect of a domestic electrical installation but I have been doing a lot of reading and its all very interesting. Personally I've said that due to the likely age of the wiring and the fact I think a gifted amatuer has carried out a few alterations to the wiring over the years I'd start again and get it rewired but time will tell?

Barrie

Barrie

 

[Barrie Patrick]

Hi StantheMan,

Thanks for your message, I'm enjoying being here.

I dont think the J/B I used is a maintenance free one but it is what I would call accessible, sure others may disagree. I know where its fitted and the trap in the floorboards of the bedroom where it is, is marked (Kitchen lighting J/B), however there is carpet and underlay over the floorboards and the dreaded furniture would need moving but this is how I was taught and I think its good enough.

Barrie

 

[Barrie Patrick]

Tut Tut lol

 

[Barrie Patrick]

Hi Clive P,

Thank you for taking the time to reply to my questions, I'm really relieved I'm not the only one who remembers that running neutrals through switches was taboo but everything evolves and if you can learn something new everyday you're doing well,

Barrie

 

[Deleted member 9648]

The reason that neutrals in switches is no longer considered bad practice is that nobody has ever come up with a valid reason as to why it is bad practice.
The arguments are that the neutral is not necessary in a switch box. That argument ignores the fact that a permanent live is not necessary at a 3 plate light point.
Another argument is that a switch box is not a suitable enclosure for joints,which ignores the fact that neither is a light fitting.

 

[Deleted member 72666]

Sorry Did not read your post properly :1eye:

Not a problem, I'm prone to doing that myself.

 

[DPG]

Hi StantheMan,

Thanks for your message, I'm enjoying being here.

I dont think the J/B I used is a maintenance free one but it is what I would call accessible, sure others may disagree. I know where its fitted and the trap in the floorboards of the bedroom where it is, is marked (Kitchen lighting J/B), however there is carpet and underlay over the floorboards and the dreaded furniture would need moving but this is how I was taught and I think its good enough.

Barrie

Definitely not accessible then I would say And the problem is, although you know where it is, no-one else does in years to come. Maybe wago's would have been better here? Daz

 

[Flanders]

Definitely not accessible then I would say And the problem is, although you know where it is, no-one else does in years to come. Maybe wago's would have been better here? Daz

I,m sure that junction box will fine and as long as all terminals are nice and tight the junction box if fixed and the cable cliped it will be good for 100 years or more !!!

 

[DPG]

I,m sure that junction box will fine and as long as all terminals are nice and tight the junction box if fixed and the cable cliped it will be good for 100 years or more !!!

Not convinced - I've seen quite a few loose terminals. Especially if there's also no strain relief on the cables. Daz

 

[Jay Sparks]

Another good reason why neutrals are connected in the switch back box's, is with the advent of the RCD. When testing your Zs on No trip, as you need to connect to the neutral as well, it's a lot easier to do at the switch, than the light fitting on ladders.

Jay

 

[Flanders]

Not convinced - I've seen quite a few loose terminals. Especially if there's also no strain relief on the cables. Daz

yes i have tloo but always belieave if its install propley in the first place then it will last for years .

 

[7029 dave]

yes i have tloo but always belieave if its install propley in the first place then it will last for years .

I agree with you, having said that any joint anywhere is going to be an fault liability.

 

[Marvo]

The reason that neutrals in switches is no longer considered bad practice is that nobody has ever come up with a valid reason as to why it is bad practice.
The arguments are that the neutral is not necessary in a switch box. That argument ignores the fact that a permanent live is not necessary at a 3 plate light point.
Another argument is that a switch box is not a suitable enclosure for joints,which ignores the fact that neither is a light fitting.

Neutrals through switch boxes is the normal way of doing things where I am and this post pretty much sums up my sentiments about it. It's something that some of the older guys feel strongly about but I've never heard a convincing argument against it.

 

[Barrie Patrick]

Have to say Thank You to everyone whose replied and I'm sorry if the topic of neutrals in light switches had previously been done to death on here but I've actually found it very useful to hear what some of the Younger guys on here actually do when installing and what they think. I think if I ever do any wiring again I'll think about running the neutral through the switch................... then Not do it LOL

One reason I remember the tutor giving us at Tech for not taking a neutral through a switch was it increases the chance of electric shock because there is a return path at the switch, I always thought this a little lame as there is already an earth there as a return path, that switched sockets outlets, spur units and double pole switches had a neutral and earth with a switch and it was deemed ok so like others I dont really have a valid argument for not doing it :-(

However, I'm afraid I will probably stick with what I know but now I wont criticise other Sparkies who do run neutrals through switches and if ever stuck I'll do it without that guilty feeling I would have once had LOL

Barrie

 

[PEG]

Welcome,Barrie, and may i take this opportunity to applaud an action,that three pages on,everybody has overlooked...

That is,that you got yer tools out,at your nieces party ...a man after my own heart...

 

[Paulgwat]

I would expect to see Neutrals being brought into light switch back boxes being something that will get more common with the rise in popularity of home automation systems as most of the lower cost systems such as Zwave and Fibaro etc need a neutral to work.

If doing a rewire I personally would bring a neutral to each light switch as a minimum, if not all of the Nautrals for that circuit.

My understanding was that the UK was the odd one out and that in most other European countries you would expect to see Neutrals in a light switch back box as a normality.

Paul

 

[M-Ty]

One reason I remember the tutor giving us at Tech for not taking a neutral through a switch was it increases the chance of electric shock because there is a return path at the switch, I always thought this a little lame as there is already an earth there as a return path <SNIP>
Barrie

You're right: It sounds like he was more familiar with the 13th Edition with its un-earthed lighting circuits, if non-conducting floors, and/or metal fittings (now luminaires) placed out of reach.

 

[hightower]

On the subject of accessibility I'm sure I've seen somewhere that a hatch in the floorboards is acceptable for screw type junction boxes. Will try and remember where I saw that. ...

 

[Midwest]

BS 7671, 526.3. Makes a start.

 

[hightower]

Must have been here in my 2365 textbook.

 

[Andy78]

On the subject of accessibility I'm sure I've seen somewhere that a hatch in the floorboards is acceptable for screw type junction boxes. Will try and remember where I saw that. ...

It's debatable really whether or not a hatch is considered accessible or not. I personally only fit MF connections under floors. I may make an exception for a marked board in a central heating cupboard or understairs cupboard that has exposed boards as it is easily spotted and accessed.
A hatch under a floor is only accessible after all the furniture has been moved and the carpet taken up. Not my idea of accessible. And it's only accessible in that manner as long as no laminate/tiles/lino is put down over it.

 

[richy3333]

Hi Again Midwest,

I have installed some down lighting fited with cold running LED's in my kitchen and utility room and downstairs toilet using the existing 3 plate lighting system, I just used a junction box to create the lighting point in each room then looped the switched live and perminant neutral and earth (cpc) from light to light, it all went in very nicely.............. Please dont tell me there is now a Reg that says I should have switched the neutral LOL

Barrie

hope that JB was a MF one

 

[Jay Sparks]

If the OP has used pork pie JB's to connect each down light, then there's no access problem because if they went into the hole for the down light, then they can be easily accessed by the same hole?? I have done this on many occasions. I would never put them under floor boards though. And Wago's are a good idea but they have only been out for 5 maybe 10 years!! How can any one guarantee they are MF??? They haven't been tested long enough.

Jay

 

[DPG]

If the OP has used pork pie JB's to connect each down light, then there's no access problem because if they went into the hole for the down light, then they can be easily accessed by the same hole?? I have done this on many occasions. I would never put them under floor boards though. And Wago's are a good idea but they have only been out for 5 maybe 10 years!! How can any one guarantee they are MF??? They haven't been tested long enough.

Jay

If they have no strain relief for the cables then they need to be fixed though. Daz

 

[Jay Sparks]

If they have no strain relief for the cables then they need to be fixed though. Daz

If the JB is resting on the under side of the ceiling, about 6 inch away from the down light, wheres the strain?? So you pull your down light down and the JB is there. Easy access, no strain??!!

 

[DPG]

If the JB is resting on the under side of the ceiling, about 6 inch away from the down light, wheres the strain?? So you pull your down light down and the JB is there. Easy access, no strain??!!

The strain relief in junction boxes is there so that when the junction box and cables are moved around, the terminations are not put under stress, especially where the relatively non-flexible t&e is used. Daz

 

[Jay Sparks]

The strain relief in junction boxes is there so that when the junction box and cables are moved around, the terminations are not put under stress, especially where the relatively non-flexible t&e is used. Daz

I know what you are trying to say but i just cant see how a downlight is gonna move around when its in a ceiling. Jay

 

[DPG]

I know what you are trying to say but i just cant see how a downlight is gonna move around when its in a ceiling. Jay

It's more the juggling around and moving things around when the boxes are pushed up into the ceiling though. Daz