Another Bathroom Downlighter Question

[Frankiesays]

Hi All, this is my first post on here. I can see people have asked this question before but I'll ask again as I want to be certain I'm doing the right thing in my particular case. I'm replacing everything in the bathroom including replacing the ceiling and replacing to old single bulb light with 240v bath/show spec downlighters x 6. I have attached a pic of what was there and a picture of the wiring underneath the rose. I have two cables coming in from the loft with the two earths twisted together, the two reds joined together leaving two wires going to the bulb. I have terminated these two wires and pulled the lot back into the loft while i put the new ceiling up. I will be joining the 6 new light fittings together presumably using the usual 3 core lighting cable but how should I connect that to the wiring I'm currently left with. All help appreciated.

 

[Taylortwocities]

You need to replace the light with a junction box. The cables go in to the junction box exactly as you have them at present.
ie
Two reds connected together and nowhere else. Earths connected together
That leaves two blacks. These will be the live and neutral connections to the downlights. You'll need to find out which is which. Do you have any sort of electrical test meter?
When you have found out, mark the live one with red or brown sleeve.

Then you 'll need new cabling to run round friom one downlight to the next. You'll need 2 core and earth. The earth connection must be carried round from supply to the last light EVEN IF THE LIGHTS THEMSELVES DO NOT NEED AN EARTH!

 

[ban-all-sheds]

replacing to old single bulb light with 240v bath/show spec downlighters x 6.

Please think about whether the fact that you'll need 6 times as many lights as you had before might indicate that the new lights are rubbish at the job of actually lighting up rooms.

Also, when you put downlights in bathrooms you need a sealed enclosure over them in the loft, large enough to provide the necessary clearance and able to take the weight of the insulation.

• http://www.nhbc.co.uk/NHBCPublicati...ical/StandardsExtra/filedownload,16553,en.pdf
  
  
• IET article on installing downlighters safely

how should I connect that to the wiring I'm currently left with.

Neutral to Neutral.
Live to Switched Live.
Earth to Earth.

Make sure you maintain the permanent live loop

• http://wiki.diyfaq.org.uk/index.php/House_Wiring_for_Beginners#Lighting
  
• https://www.diynot.com/wiki/Electrics:Lighting

 

[Frankiesays]

You need to replace the light with a junction box. The cables go in to the junction box exactly as you have them at present.
ie
Two reds connected together and nowhere else. Earths connected together
That leaves two blacks. These will be the live and neutral connections to the downlights. You'll need to find out which is which. Do you have any sort of electrical test meter?
When you have found out, mark the live one with red or brown sleeve.

Then you 'll need new cabling to run round friom one downlight to the next. You'll need 2 core and earth. The earth connection must be carried round from supply to the last light EVEN IF THE LIGHTS THEMSELVES DO NOT NEED AN EARTH!

Thanks for that Taylortwocities. Can I assume that the earth from the new cable will be connected to the currently twisted pair earths which will shortly be in the junction box?

 

[Frankiesays]

Please think about whether the fact that you'll need 6 times as many lights as you had before might indicate that the new lights are rubbish at the job of actually lighting up rooms.

Also, when you put downlights in bathrooms you need a sealed enclosure over them in the loft, large enough to provide the necessary clearance and able to take the weight of the insulation.

• http://www.nhbc.co.uk/NHBCPublicati...ical/StandardsExtra/filedownload,16553,en.pdf
  
• IET article on installing downlighters safely

Neutral to Neutral.
Live to Switched Live.
Earth to Earth.

Make sure you maintain the permanent live loop

• http://wiki.diyfaq.org.uk/index.php/House_Wiring_for_Beginners#Lighting
  
• https://www.diynot.com/wiki/Electrics:Lighting

Thanks for the reply and the documents - now and and saved for future use. Although I agree with your sentiments re the choice of lamp (the other bathroom has a single 13w LED lamp which is superb), the current Mrs H is in charge of design for this project so who am I to criticise a bigger LED bulb than present would have been so much easier.

 

[winston1]

the current Mrs H is in charge of design for this project so who am I to criticise a bigger LED bulb than present would have been so much easier.

You need to be firm. Are you a man or a mouse.

 

[Frankiesays]

Thanks for all these very useful and prompt responses. I'm just placing an Amazon Prime order for my electrical tester. As I'm fitting lamps specifically for bath/shower rooms they are sealed and must have LED GU10's fitted which will generate very little heat. Would an electrician still fit thermo hoods just in case some idiot changes them for halogen lamps in the future? My lamps won't really need them but I don't want a future owner of my house burning the place down.

 

[flameport]

Would an electrician still fit thermo hoods just in case

No, as that's not what they are for.
Hoods are there to prevent fire passing through the holes - as in when your bathroom is filled with smoke and flames and is already totally destroyed.
They are not there to prevent overheating.

However if you have insulation above the bathroom, you will need to fit some kind of rigid support, cover or similar to maintain a space between the back of the lights and the insulation above so they do not overheat. This applies with LED, halogen and any other type of lamp.

 

[JohnD]

...you can make up such a cover with five squares of plasterboard, nailed together as an open-ended box. Plasterboard doesn't burn so is I think quite a good choice. It will prevent loft insulation flopping onto the lamp, and also reduce steam rising and causing loft damp.

If you buy fire hoods, they come with an intumescent lining that swells up in the event of a fire. They're quite cheap now.

 

[Iggifer]

Or some manufacturers do insulation caps for their fittings to allow you to bury them in insulation. Aurora do them for their fittings and there’s a few other manufacturers too.

Cheaper and easier than having to mess around with plasterboard to just buy the correct fittings in the first place.

A upturned flower pot is cheap as chips too if you can get a good sized one cheap enough

 

[ban-all-sheds]

I'm just placing an Amazon Prime order for my electrical tester.

What sort of tester is it?

 

[ban-all-sheds]

A upturned flower pot is cheap as chips too if you can get a good sized one cheap enough

Will be piggin' useless as a vapour seal though....

 

[Frankiesays]

What sort of tester is it?

https://www.amazon.co.uk/dp/B01MSSQNG6/ref=pe_3187911_189395841_TE_dp_2

 

[ban-all-sheds]

Sent it back unopened so that there can be no grief about the state of it.

Buy a proper 2-pole tester instead - those magic wands are dangerous.

 

[Taylortwocities]

Whssign

• Taylortwocities
• 16 Jul 2016

What he said

You need a two probe voltage tester. Those wands lie to you, and they will not help with problems with the neutral connection, which is responsible for at least half of the problems we encounter.