running cable for first fix

[greeny4]

im currently about to run the cable on a new build extension upstairs. Downstairs i looped a twin and earth to each switch and then laid from each switch to each light, joining the neutral at each switch with a fixing block and pushing it to the back behind each switch. Is this okay to do as ive been told this is the hard way of doing it? any opinions appreciated, cheers Rick. sorry about previous post and mis understanding.

 

[kevindgas]

im currently about to run the cable on a new build extension upstairs. Downstairs i looped a twin and earth to each socket and then laid from each socket to each light, joining the neutral at each socket with a fixing block and pushing it to the back behind each switch. Is this okay to do as ive been told this is the hard way of doing it? any opinions appreciated, cheers Rick.

would you kindly explain this as it looks like you have mixed usage lighting and power !

 

[sparkwright]

i think you mean switches, not sockets. this is a lighting circuit i take it. the sockets circuit would be entirely separate.

for a lighting circuit this sounds acceptable. make sure you use boxes at least 25 mm deep.

 

[plugwash]

Essentially there are three main ways of doing lighting wiring (there are others too but they are less common and you will also often see mixtures of approaches).

The junction box method: Main circuit cable goes through a junction box, from that junction box run cables to the switch (with permanent live, switched live and earth) Rarely used in new installation due to the cost of the junction boxes, the fact that all connections are supposed to be accessible and the fact that it introduces unnessacery extra connections. Often seen when existing installations are modified.

The loop in method: Main circuit cables go to the light fitting and then a cable with live and switched live drops from the fitting to the switch. This is probablly the most common method as providing you use traditional pendants or striplights it is the cheapest and easiest. The trouble is it is often a PITA if you want to fit fancy fittings to such a system as fancy fittings are often lacking in wiring room.

The loop at swtich method (what you describe): the main circuit cable goes to the switches and then switched live and neutral go from the switch to the light. The advantage of this method is that you avoid junction boxes and yet still only have a single cable at the light (good for fancy fittings), the downside is that you generally end up with longer cable runs (= more cost and more work and probablly the reason you heard this described as the hard way). You also need to use deeper backboxes to allow for the extra wiring at the switches.

P.S. whether you go for loop at fitting or loop at switch consider using 3+E for the runs from light to switch. It is often handy to have an extra core when modifying the system in the future.

 

[Taylortwocities]

It is the hard way to do it, if you have pendant lamp fittings as all of the connections are in the pendant.

Your method is the way i do it if the luminaire is wall lights or downlights

PS 25mm boxes will probably be too shallow if you are using dimmers and also have the neutral block in there.

 

[safesinbad]

P.S. whether you go for loop at fitting or loop at switch consider using 3+E for the runs from light to switch. It is often handy to have an extra core when modifying the system in the future.quote]

Very good idea, so if u wish u would have a permanent live at the fitting also

 

[sparkwright]

P.S. whether you go for loop at fitting or loop at switch consider using 3+E for the runs from light to switch. It is often handy to have an extra core when modifying the system in the future.quote]

Very good idea, so if u wish u would have a permanent live at the fitting also

or a spare neutral at switch!

 

[safesinbad]

why would use a ''spare neutral'' there is already obe there.

wire it in 1.5 twin and you would have a switched live, neutral and cpc

wire it in 1mm/1.5mm 3core and you would have a switched live, neutal, cpc and a spare. Why would you use the spare as a neutral when there is already a neutral there?

 

[ban-all-sheds]

im currently about to run the cable on a new build extension upstairs.

When you submitted your application for Building Regulations approval, what did you say would be the way you'd comply with Part P?

 

[sparkwright]

why would use a ''spare neutral'' there is already obe there.

plugwash was discussing the benefits in running a 3 core+e between the switch and light on both loop in rose systems and feed the switch systems.

if you feed the switch the extra core can provide a perm live to the light which may come in handy for adding to the circuit.

however, if you have a loop in rose system (three plate) then the extra core could give you a neutral at the switch, again which could be very useful for extending the circuit.

you see?

 

[ColJack]

not quite mastered the "quote" button yet then?

 

[sparkwright]

not quite mastered the "quote" button yet then?

you got that right!

was struggling to get to get two quotes on the same post.

see how this one turns out...

 

[greeny4]

So whats the end verdict? is is acceptable to lay it the way i said, run a twin and earth looped to each switch with a cable running from each switch to the lights. The neutrals will be joined and pushed to the back behind the switch, thanks again for your help Rick.

 

[ColJack]

yes fine..

 

[ban-all-sheds]

im currently about to run the cable on a new build extension upstairs.

When you submitted your application for Building Regulations approval, what did you say would be the way you'd comply with Part P?