Changing ceiling rose in a new build house

[Daniel Morgan]

Hi all sorry if this is the wrong section, im currently studying to become and electrician and so far learned the basics. A friend of mine has asked if i can change his bathroom and on suite light. Each bathroom he wants light changing has a extractor fan as well wired to the lights. Looked at the current wiring arrangement to see how it had been wired in since the house was built. Below is a pic of what he has at the moment, plus instructions for the new light.










Based on the above this is how i was going to approach the job but wanted a second opinion from the pros.

New light

Line from light ---------- both switch line wires identified with a brown sleeve (black wire with brown sleeve and blue wire with brown sleeve)


Earth/CPC from light ------------ All cpc wires from all looms


Neural from light -------------- both single blue wires and the gray cable with the blue sleeve (identified as the neutral)


4th terminal blank from light side ----------- all brown cables into this one terminal



If the above arrangement is correct are we likely to come across any issues or over current? As with mounting the unit to the ceiling will it just be self tap screws straight into the ceiling?

Thanks

 

[davesparks]

You may come across an issue getting a good termination on four conductors in one of those terminals so you may be better off fitting short tails in to them and using a better connector on the other end.

To be honest I would consider a joint xternal to the fitting and a heat resistant flex run into the fitting itself if I was doing that.

I would however suggest that if you are at an early stage in your apprenticeship that you don't yet have confidence in this then it would be best to ask your friend to wait a while until you do, or get your apprenticeship mentor to advise you as they will best know your ability at this stage.

 

[Daniel Morgan]

Thanks for your reply yeah its annoying knowing the theory of something but when you have has hardly any practical experience to compensate for any issues is another thing. Thanks again.

 

[dave274]

The manufacturer puts an extra connector for the loop but gives you a cable entry that you would struggle to get a single cable through.

 

[gnselectricals]

I'd cut round the rose and recess into ceiling with new 3core to new light

 

[gnselectricals]

Just a joke there, a suitably accessible mf jb for me with a 3core to new light

 

[sparksburnout]

Just a joke there, a suitably accessible mf jb for me with a 3core to new light

Suitably accessible maintenance free JB?

 

[gnselectricals]

Suitably accessible maintenance free JB?

Yeah mate that's the way I'd go

 

[telectrix]

if you cut a hole in the ceiling and use a wagobox or line enclosure to terminate the T/E s and then use flex to the fitting, that would be ideal.

 

[123]

Just a joke there, a suitably accessible mf jb for me with a 3core to new light

If its accessible, why does it need to be maintenance free?

 

[Adam W]

So what you've got there is:
supply (brown & blue)
feed to next light (brown & blue)
live feed and live return to switch (brown & blue sleeved brown)
3 core to fan (brown to permanent live, black with brown sleeve to switched live, grey with blue sleeve to neutral).

If there's enough space in the back of the fitting and heat isn't going to be an issue I'd go with what the manufacturer suggests and join some of the cables in the fitting using wagos.

On a side not the way it's been wired seems a bit cumbersome - if there's a fan isolator some of the connections could have been spread across that and the switch, or maybe a deep backbox used and the connections made in the back of that; a lot of modern light fittings don't give you much space to accommodate extra connections like switched lives or fan connections.

 

[Martin Kerr]

Is there any specific reason you do not use twin brown ,that side of the pond ?
we normally wouldn't use brown and blue for switch wires

 

[Risteard]

Is there any specific reason you do not use twin brown ,that side of the pond ?
we normally wouldn't use brown and blue for switch wires

And let's not forget that BS 7671 states a preference for a conductors being identifiable throughout its length, so really it's better practice to use twin brown instead of brown & blue.

Some day they may also discover the delights of Scrulox screws!

 

[sparksburnout]

And let's not forget that BS 7671 states a preference for a conductors being identifiable throughout its length, so really it's better practice to use twin brown instead of brown & blue.

Some day they may also discover the delights of Scrulox screws!

What a load of cobblers. So we have a bit of T&E going from a ceiling rose to a switch - any spark with half a brain will know that the blue or black is likely to be a SL return. Yeah put some sleeving on of course, but really! In most, particularly older lighting set-ups, it's just safer to assume any colour could be anything, specially if DIY has been involved, I've even seen CPC's used as SL's!!

 

[Adam W]

Is there any specific reason you do not use twin brown ,that side of the pond ?
we normally wouldn't use brown and blue for switch wires

Using brown and blue makes identifying the switched live much easier, and saves carrying two lots of cable around.

 

[Risteard]

Using brown and blue makes identifying the switched live much easier, and saves carrying two lots of cable around.

I've never had a problem with twin brown. Anyway, it is often irrelevant which one is the switched return for the phase conductor (e.g. 1-way switching).

 

[Risteard]

What a load of cobblers.

How is it cobblers. BS 7671 states that identification of conductors are "preferably throughout their length". So there clearly is a preference stated.

Here many would make you rip it out if you installed brown & blue (even if it was sleeved). It is considered bad practice here. And if I drive just 1.5 miles and cross the border it is expressly prohibited.

 

[sparksburnout]

Because its bloody obvious to anyone that if its a switch drop both conductors are likely to be live. Sleeving is perfectly acceptable, IMO.

 

[davesparks]

How is it cobblers. BS 7671 states that identification of conductors are "preferably throughout their length". So there clearly is a preference stated.

Here many would make you rip it out if you installed brown & blue (even if it was sleeved). It is considered bad practice here. And if I drive just 1.5 miles and cross the border it is expressly prohibited.

Out of interest, what do you do for a two gang switch? Do you use a three core and sleeve the black and grey or would you run a twin brown and a single?

 

[Risteard]

Because its bloody obvious to anyone that if its a switch drop both conductors are likely to be live. Sleeving is perfectly acceptable, IMO.

No-one said it wasn't - simply that correctly identified conductors throughout their length is better.

 

[Risteard]

Out of interest, what do you do for a two gang switch? Do you use a three core and sleeve the black and grey or would you run a twin brown and a single?

Almost always twin brown for strappers and singles either end (presuming you mean 2-way).

Although some use 3-core, I would say the majority don't. Again, across the border the use of 3-core (or three-phase cable as they describe it) is not permitted.

 

[sparksburnout]

Almost always twin brown for strappers and singles either end (presuming you mean 2-way).

Although some use 3-core, I would say the majority don't. Again, across the border the use of 3-core (or three-phase cable as they describe it) is not permitted.

OOeerrrr

 

[davesparks]

Almost always twin brown for strappers and singles either end (presuming you mean 2-way).

Although some use 3-core, I would say the majority don't. Again, across the border the use of 3-core (or three-phase cable as they describe it) is not permitted.

I meant a 2 gang, 1 way. So I would run a three core from the rb4 to the switch, brown for common and black and grey for the two switched lives

 

[Risteard]

I meant a 2 gang, 1 way. So I would run a three core from the rb4 to the switch, brown for common and black and grey for the two switched lives

With a 2-gang 1-way just a twin brown from one of the luminaires, and then a single to the other luminaire with the commons bridged in the switch.

 

[davesparks]

With a 2-gang 1-way just a twin brown from one of the luminaires, and then a single to the other luminaire with the commons bridged in the switch.

Which wouldn't happen over here as we don't have sheathed singles available.
So for me it would be a three core to the switch from the rb4 and a twin to each light from the rb4

 

[Risteard]

Which wouldn't happen over here as we don't have sheathed singles available.

I wasn't aware of that. PVC/PVC single brown or brown & earth, or single blue (or unusually blue & earth) are readily available here.

 

[davesparks]

I wasn't aware of that. PVC/PVC single brown or brown & earth, or single blue (or unusually blue & earth) are readily available here.

I wish they were available, it would make some things a lot more simple/logical

 

[telectrix]

Which wouldn't happen over here as we don't have sheathed singles available.
So for me it would be a three core to the switch from the rb4 and a twin to each light from the rb4

i wouldn'tcall this unavailable:


Welcome to Doncaster Cables - Single Core PVC Insulated, PVC Sheathed Cables

 

[davesparks]

i wouldn'tcall this unavailable:


Welcome to Doncaster Cables - Single Core PVC Insulated, PVC Sheathed Cables

Yeah but when was the last time it was commonly stocked by a wholesaler?

 

[telectrix]

point taken. shame as it's very useful for strapping the exhaust back up on a landrover.

 

[sparksburnout]

Load o fuss about nowt. I hate old houses where the lighting circuit is wired in singles. Bloody cables slung about all over the place takes ages to work out what's going where half the time. Nothing wrong with using 3 core cables for 2 way lighting at all, in fact, best way. How do you lads go on with armoured then? Do you have specialised Brown Blue and Green/Yellow SWA?????

 

[Risteard]

How do you lads go on with armoured then? Do you have specialised Brown Blue and Green/Yellow SWA?????

Not in the north, but in the south 3-core SWA is brown, blue & green/yellow. Although ETCI Wiring Rules permit the use of the armour as a cpc it is never actually done, and it wouldn't be permissible to remark the conductors on the SWA. (Except for recently it has been made legal to remark the blue as green/yellow with retrospective effect.)

In fact a job I did recently in Bridgend, Co. Donegal (right on the border - less than 5 minutes from me) needed a 3-core SWA. The local wholesalers didn't stock any in single phase colours so I had to drive to Letterkenny in Co. Donegal 20 miles away to get the cable.

 

[Leesparkykent]

You can get 3core swa here which is brown,blue, green and yellow. Its just not very common and generally a special order.

 

[Risteard]

You can get 3core swa here which is brown,blue, green and yellow. Its just not very common and generally a special order.

Granted, but unfortunately it's not always an option to wait for delivery!

And before anyone asks why not use 2-core - no-one stocks it!

 

[sparksburnout]

Blimey my flabber has never been more gasted. Last time I was in Southern Ireland (Admittedly a while back now, on the West coast), we went into a local "shop", for some butties, it being a "general store". Turns out not only is it a general store and post office, but at the end of the room is a coffin resting on a table, yep its a funeral parlour as well, and to top it off, there is a couple of old boys supping the black stuff up the other end of the shop, this at 9:30 am. Fantastic, what a place. So I am amazed anyone gives a ---- about the colours of anything really!!! Hey ho.

 

[Risteard]

LOL. Believe it or not electrical work has become much more regulated over the past two and a half years. Although the Wiring Rules have been around longer than that.

 

[sparksburnout]

LOL. Believe it or not electrical work has become much more regulated over the past two and a half years. Although the Wiring Rules have been around longer than that.

Mmmm I will take your word for that. Anyway as it happens I am off to see a G&R tribute now so see you later

 

[Risteard]

Mmmm I will take your word for that. Anyway as it happens I am off to see a G&R tribute now so see you later

Have fun, but don't be Dancin' with Mr. Brownstone...

 

[Dave OCD]

You can get 3core swa here which is brown,blue, green and yellow. Its just not very common and generally a special order.

And much more expensive !