Downlight installation - is this safe?

[Novicenovice]

I'm installing 5 x 50w mains halogen downlights in my kitchen, I'm not an electrician so just want to check this is totally safe.

I bought some 1.5 Twin & earth cable but as the light housings swivel 360 degrees with no stop - I'm reluctant to use this as it doesnt bend much and I guess might become loose at some point. My local electrical factor has sold me some .75mm 3 core flex - will this be adequate?
I presume I can just connect the fittings by looping cable from one fitting to the next. Also - there is no earth connection on the (metal) fittings - I presume there is therefore no need to earth them (there is an earth on the existing supply).

Finally... they are connected to a dimmer rated at 400w - have hooked it up and seems to work ok - but have heard the dimmer needs to be rated 2x the fittings if they are mains halogen?

Thanks!

 

[ban-all-sheds]

I'm installing 5 x 50w mains halogen downlights in my kitchen, I'm not an electrician so just want to check this is totally safe.

It's totally notifiable....

My local electrical factor has sold me some .75mm 3 core flex - will this be adequate?

Probably. It depends on the rating of your fuse/MCB. 1mm² would have been a safer bet.

It should be high temperature cable - those lights can get hot. How close to the light does the cable get?

And how will you join it to the circuit cable?

presume I can just connect the fittings by looping cable from one fitting to the next.

How far apart are they? It might be preferable to route the lighting circuit close to each position and just run short lengths of flex.

Also - there is no earth connection on the (metal) fittings - I presume there is therefore no need to earth them (there is an earth on the existing supply).

You must not earth them, but also you must not cut the earths back and you must maintain earth continuity through the circuit.

Finally... they are connected to a dimmer rated at 400w - have hooked it up and seems to work ok - but have heard the dimmer needs to be rated 2x the fittings if they are mains halogen?

It depends on the dimmer - what do the instructions or the specs on the makers website say?

 

[Novicenovice]

Thanks for the reply.
There's a chance the cables could get close to the lights if the fittings get rotated a few times over time. Is the high temperature cable easily available and is there any particular name or spec for it? I did read somewhere that even hi temp cable would not resist heat from a halogen as they get very hot..

The lights are about 800mm apart, the I plan to attach them to the same connections left from the previous lights, a cluster of three surface mounted spots, using a junction box. Then run cable (not connecting the earths) from one light to the next, terminating at the fifth one.

 

[RF Lighting]

I plan to attach them to the same connections left from the previous lights, a cluster of three surface mounted spots, using a junction box.

Will this junction box remain accesible?

Then run cable (not connecting the earths) from one light to the next, terminating at the fifth one.

Please, for the sake of your own safety, engage the services of a competant electrician.

 

[Novicenovice]

Point taken.

The comment about earths follows 'ban all shed's post above:

you must not earth them, but also you must not cut the earths back and you must maintain earth continuity through the circuit.

 

[ban-all-sheds]

Thanks for the reply.
There's a chance the cables could get close to the lights if the fittings get rotated a few times over time. Is the high temperature cable easily available and is there any particular name or spec for it? I did read somewhere that even hi temp cable would not resist heat from a halogen as they get very hot..

Silicone rubber should be good to well over 150°...

Then run cable (not connecting the earths)

Please read "you must maintain earth continuity through the circuit" again.

 

[Novicenovice]

I envisaged spuring off an existing loop-in circuit like this - the query was about the earth connection if there are no erthing points on the lights. As a matter of course I would maintain earth continuity in the loop-in circuit - is that what you meant?

Out of interest why would they make light without an earthing point?

http://www.flickr.com/photos/24253869@N04/2300959842/

 

[Novicenovice]

ps. realize the switch is drawn wrong - should be 2 lives...

 

[securespark]

Out of interest why would they make light without an earthing point?

If it were class II?

 

[Novicenovice]

sorry pics gone - try this:

http://www.flickr.com/photos/24253869@N04/2300211331/

 

[ban-all-sheds]

As a matter of course I would maintain earth continuity in the loop-in circuit - is that what you meant?

No - I meant on the cable that runs through each light as well - that's part of the circuit.

What if you, or a someone else, changes those lights in the future for Class I ones, or adds one which is Class I?

 

[Novicenovice]

So the layout as shown in the diagram is a correct wiring arrangement? - though the earth is not used in that part of the circuit it should be there and continuous all the way to the last lamp where it terminates.