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.