"bad practise"

[double 22]

After completing my exams i was only taught one lighting wiring system:

Phase / neutral feed to fittings, then twin to switch, you know like all the diagrams we're shown....

A few on the course (2360) who'd done more on site work than me kept saying about another way, but the teachers just told us it was "bad practice" to wire any other way than i've mentioned above.

Now, I'm "learning on the job", and all is fine.
But the wiring system for lights we always use is, permanent live feed (brown single + earth) to switches, neutral (blue single) to fittings, and switch wire (bn single and earth again).

I've mentioned what the teachers said, but get no favorable responce, so I'm just asking...
Is this system being phased out ?
Is it less safe than what we are taught nowadays ?

Any other comments ?

 

[RF Lighting]

No, its perfectly acceptable to wire lights in this way, and it is again becoming a common way of doing things with the advent of fancy fittings or downlighters in every room of the house (It saves having an un-needed permanent live at every light fitting.)

You can also wire lights where you loop the live and neutral round all the switches, and just take a T&E to the light fitting (carrying switched live and neutral)

There are diagrams and explainations of all these methods in the Wiki


//www.diynot.com/wiki/electrics:lighting

 

[ricicle]

As long as the wiring complies to regulations and the system works as intended then there is no incorrect way of wiring lighting circuits.Some might be a little long winded, use a bit more cable than was needed or might have a simpler way than them.It depends on what was in the mind of the designer/installer at the time.
The recognised way for a long time and still is to a certain extent is the 'loop-in' system where feeds are taken from the CU and daisy-chain to each light on the circuit.Switch wires are then taken from each light to the relevant switching positions.This can leave up to 3 or more cables at each light making it tricky to fit fancy light fittings.Some sparkies now wire feeds to the switches, join neutrals through and take a single cable to the light making the fitting of other lights easier

Note:Must learn to type faster!!

 

[securespark]

To my mind having only a switch & neutral at the ceiling position must be nightmare if you want to extend.....

 

[RF Lighting]

Loft light. The electricians saviour

 

[plugwash]

To my mind having only a switch & neutral at the ceiling position must be nightmare if you want to extend.....

Assuming the cables between the switches run through the loft it shouldn't be too hard to find one of them and break into it with a JB.

And looping at switches is easier if you want to add extra lights from an existing switch position too.

Still there is a lot to be said for using 3+E for switch drops regardless of which end of the drop the looping happens at.

 

[tim west]

I still go with the way that i was taught with the loop between roses and single T&E to switch drops. It's got to be easier not having to run several cables down a wall together rather up in a loft space or floor void.
I suppose with the advent of stud partioning it has let this sort of practice become favourable?

 

[Spark123]

One problem with using the loop in method is the amount of wires which end up at each ceiling rose, I seem to remember reading in the DPC (Draft for Public Comment) for the next edition of the regs that through wiring may only permitted in luminaires which have been designed for this purpose hence I can see the loop in at the switch method becoming more common if this regulation is adopted.

 

[plugwash]

I still go with the way that i was taught with the loop between roses and single T&E to switch drops. It's got to be easier not having to run several cables down a wall together rather up in a loft space or floor void.

sure if its all roses thats the easiest way to do it but fancy fittings often make it a right PITA to get 3 cables in and join up the permanent lives.

you can use junction boxes of course but people tend to board over the loft making those inaccessible.

 

[securespark]

To my mind having only a switch & neutral at the ceiling position must be nightmare if you want to extend.....

Assuming the cables between the switches run through the loft it shouldn't be too hard to find one of them and break into it with a JB.

What about the ground floor lighting?

Second, I thought the whole idea of these methods of wiring were to do away with concealed joints.

 

[Warrior]

After completing my exams i was only taught one lighting wiring system:

Phase / neutral feed to fittings, then twin to switch, you know like all the diagrams we're shown....

A few on the course (2360) who'd done more on site work than me kept saying about another way, but the teachers just told us it was "bad practice" to wire any other way than i've mentioned above.

Now, I'm "learning on the job", and all is fine.
But the wiring system for lights we always use is, permanent live feed (brown single + earth) to switches, neutral (blue single) to fittings, and switch wire (bn single and earth again).

I've mentioned what the teachers said, but get no favorable responce, so I'm just asking...
Is this system being phased out ?
Is it less safe than what we are taught nowadays ?

Any other comments ?

Correct me if i am wrong but the lighting method wich you describe, is it not the difference between, twin and earth method and conduit singles metod

 

[ColJack]

the problem with the "loop in at the switch" method is that you either need double pole switches, or a connector block for the neutrals which in my opinion is bad practice..

you also need to install deeper back boxes to accomodate the number of extra cables ( you have 3 T+E cables for 1 light switch rather than 1 T+E the "proper" way.. )

 

[plugwash]

the normal conduit method is to only take stuff where it needs to go, that is permanent lives go to the switches, neutrals go to the lights and switched lives run from the switches to the lights. Earths normally run alongside the lives (or are sometimes formed by the conduit itself).

With T&E you can't really do that (you can get single brown and earth and double insulated single core blue but th ey aren't easy to get and I suspect they are quite expensive). Therefore when wring with T&E you have 3 main choices (many systems end up as hybrids of theese as they are expanded).

1: traditional loop in at rose: This is economical on cables and fittings and no concealed joints but its a bitch to do with cramped imported light fittings. Also while it is possible to extend from a rose with this system in my experiance its a right bitch getting the lids on to a rose where this has been done.
2: junction box: This avoids the problem of getting wires into fancy light fittings but keeping the junction boxes accessible is a pain (in reality people often don't bother). You could use crimps or soldering to avoid the accessibility issues but crimps aren't really designed to take more than two cables and most sparkies don't carry a decent soldering iron afaict.
3: loop at switch. If you use a deep enough box there is plenty of space in the switch box for the neutrals regardless of the faceplate style and all connections are accesible. The downside is that you have to get three cables down a wall.

I suspect the reason this isn't mentioned at collage is that teaching beauracracies tend to lag a few years behind reality.

 

[ebee]

No, its perfectly acceptable to wire lights in this way, and it is again becoming a common way of doing things with the advent of fancy fittings or downlighters in every room of the house (It saves having an un-needed permanent live at every light fitting.)

You can also wire lights where you loop the live and neutral round all the switches, and just take a T&E to the light fitting (carrying switched live and neutral)

There are diagrams and explainations of all these methods in the Wiki


//www.diynot.com/wiki/electrics:lighting[/QUOTE]

An uneeded permanent live at every fitting?

 

[ColJack]

you only really need a switched live and neutral at the light fitting ( and an earth if it's metal.. )