Lighting circuit and Low voltage lights!

[r1chg1lbert]

Hi all

Now, I never touch electrics (that's what professions sparks are for) but I'll replace 'like for like' if it invlolves unscrewing a terminal. So...

This weekend I was up in the loft adding some top up insulation, and lifting the cables as I did so I managed to disconnect some wires from the low voltage transformer for the bathroom downlights. When I looked at the transformer I could see that it was cracked / damaged so I replaced it 'like for like' and connected everything back up as it was - I have working lights!

So, when I look at the way it's wired it's like this - from the pull switch I have a live (red sheath) and earth (unsheathed) in the same cable and the live wire is connected to the transformer (as the instructions say no earth is required), but the neutral (black sheath) appears to run in a separate cable and it looks to me as though the neutral wire has been cut and both ends connected to the transformer. I'm guessing that the correct way to do this would be to use a junction box for the neutral wire? Is this correct? I'm getting a spark in to have a look soon but just wanted to put my mind at rest as I thought lighting circuits were always twin and earth (1.5mm).

Thanks guys

Rich

 

[plugwash]

lighting circuits have been wired in all sorts of ways over the years

Afaict technically yours is probablly not compliant with current regs because every "live conductor" including neutral is supposed to be accompanied by an earth preferablly in the same cable but at least in close proximity. Also you do not say if this neutral is double insulated or not (if it's not thats a noncompliance). Still these are both relatively minor noncompliances IMO and not something to immediately worry about.

There is nothing wrong with putting multiple wires in a terminal as long as they are all held securely.

 

[r1chg1lbert]

Thanks Plugwash!

Like I say I don't touch electrics (leave it to you guys) but I'm pretty sure now I can leave it a few days until my spark gets here.

Thanks again

Rich

 

[ricicle]

I hope you made sure said transformer was not buried beneath the insulation either !

 

[r1chg1lbert]

well it was buried (as were the downlighters) but I took the advice posted on here and fixed it to a rafter, and also used some drainage pipe to place over the downlighters - and I'm glad I did because they kick out so much heat its unreal1

 

[ban-all-sheds]

You may be interested to know that by doing that you have broken the law and will be causing your roof timbers to slowly rot.

 

[r1chg1lbert]

No one mentioned that on here! I don't understand how that breaks the law because the instructions on the downlighters says clear any insulation away from the lights, which is what I've done by using drainage pipe to separate the light from the insulation (I've not covered it). Also wouldn't all downlighters cause timbers to rot using this argument?

What do you recommened I do? Any advice is appreciated!

Thanks

 

[ban-all-sheds]

No one mentioned that on here!

I just have....

I don't understand how that breaks the law

It will contravene Parts C and L of the Building Regulations.

because the instructions on the downlighters says clear any insulation away from the lights, which is what I've done by using drainage pipe to separate the light from the insulation (I've not covered it).

Yes, but they don't tell you not to reinstate the insulation, keeping it a specified distance away, and they don't tell you not to seal the hole, do they?

Also wouldn't all downlighters cause timbers to rot using this argument?

Yes, and the problem is particularly acute with holes in bathroom ceilings as the air going into the loft will be particularly moisture-laden.

What do you recommened I do? Any advice is appreciated!

http://www.nhbc.co.uk/NHBCPublicati...ical/StandardsExtra/filedownload,16553,en.pdf

 

[r1chg1lbert]

Thanks - that's pretty clear then! Makes absolute sense to me!

Any suggestions what to use to enclose the downlighters? I'm thinking plasterboard as plaster shouldn't ignite but not sure about the paper backing.

Thanks

 

[davelx]

http://www.nhbc.co.uk/NHBCPublicati...ical/StandardsExtra/filedownload,16553,en.pdf

Interesting inaccuracies regarding Part P in that doc!

 

[ban-all-sheds]

Any suggestions what to use to enclose the downlighters? I'm thinking plasterboard as plaster shouldn't ignite but not sure about the paper backing.

Plasterboard will be fine.

 

[DCC]

Any suggestions what to use to enclose the downlighters? I'm thinking plasterboard as plaster shouldn't ignite but not sure about the paper backing.

Plasterboard will be fine.

Will it? Normal plasterboard? Fraid not, that would be breaking the rules again.

 

[ban-all-sheds]

Why?

 

[DCC]

Because the guidance you linked states that an non combustible material should be used and normal plasterboard isn't.

 

[properleckie]

downlights for a bathroom should be 'room sealed' type anyway, then a pipe above to keep insulation clear is all needed since no through flow of heat from room just convected heat from lamp with no moisture.
better still do away with the hideous things and fit a proper bathroom light