Using flex to interconnect halogen spots

[thefuzz247]

Ive temporarily (whilst the ceiling is still down) wired 6 halogen spots in parallel from a central junction box with 1.5mm t&e. To make the final wiring easier Ive thought about using 1.5mm flex instead, as its easier to fix into the spot "housings/connectors". Is there any reason why this shouldnt be done?

Also how should the earths be connected at each spot? as they only have 2 connectors (obvioiusly l & n) Should a connection to earth be made for the metal back section of the fitting for instance?

Thanks in advance for the advice.

 

[baldelectrician]

Use a choc box or a small joint box to wire the flex into the fixed wiring.

I personally only use 12V Halogen lamps and fittings, and wire trannys at each light, the lamps last longer, are cheaper to buy, and give a better light.

If the lights are class II don't connect the earth at the light.

same as you MUST not connect an earth to 12v SELV light fittings.

 

[plugwash]

ideally you would use 2 core flex for low voltage lights avoiding the issue of a redundant and possiblly misleading earth core.

unfortunately it can be hard to get this in larger sizes, so that leaves the question of what to do with the earth core. i'd say that since SELV systems should never have an earth it should be cut back and taped up but i'm not sure what the pros will say about that.

 

[thefuzz247]

ideally you would use 2 core flex for low voltage lights avoiding the issue of a redundant and possiblly misleading earth core.

unfortunately it can be hard to get this in larger sizes, so that leaves the question of what to do with the earth core. i'd say that since SELV systems should never have an earth it should be cut back and taped up but i'm not sure what the pros will say about that.

Sorry I think I should have been clearer! The spots are recessed 240v gu10 type and not lv. They are spaced about 1-1.5m away from each other and I really just want to know can I use flex to interconnect this distance as opposed to t&e?

The lights do not seem to require an earth so are you saying I should simply use 2 core so as not to confuse? I was just thinking that I could use 3 core flex and leave the earth in a choc block in case ever needed in future?

 

[baldelectrician]

GU 10 are crap, but as you have them that will have to do.

Use twin and earth connect earth at supply side but just terminate it in connector box at other side, without going to light.

 

[Spark123]

The lights do not seem to require an earth...

Never assume, if they don't require earthing they should have a double insulated marking on them (square in square). If there is no double insulated marking on them they will probably require earthing. Did you get an instruction leaflet with them?, this should tell you how to connect the light up.

 

[thefuzz247]

The lights do not seem to require an earth...

Never assume, if they don't require earthing they should have a double insulated marking on them (square in square). If there is no double insulated marking on them they will probably require earthing. Did you get an instruction leaflet with them?, this should tell you how to connect the light up.

Thanks - Ive found the instructions and they say class 2, square in square thingy - no earth required. So can I just use flex to interconnect then? And two or 3 core?

 

[baldelectrician]

The regs require an earth at every outlet, if the fittings do not require an earth you don't connect the earth to them.

Flex should't be used for fixed wiring- only cable.

Take a cable to each light - daisy chain it, use a joint box / choc box to terminate at each light and connect a short length of two core flex from there to the fitting.

All connections must be enclosed- this is why a choc / joint box is used.

I prefer choc boxes with crimps or connector block- you can remove them from the ceiling void and get at them

All joints must be accessible.

 

[thefuzz247]

GU 10 are rubbish, but as you have them that will have to do.

Use twin and earth connect earth at supply side but just terminate it in connector box at other side, without going to light.

Can someone enlighten me as to why gu10s are rubbish? (Presumably as opposed to lv?)

It seems to me its better to have a low current and a high voltage - rather than the high ampage and low voltage (not to mention transformers) of an lv solution? I thought that ampage was always the one to avoid if possible as it causes things to catch fire generally?

Then again perhaps Im being a complete numpty on this!! I wouldnt be surprised

 

[baldelectrician]

Mains lamps, comparing like for like give a poorer light output and less colour rendering, they are more costly to replace and the lamps last less time

Mains halogens are (generally) widely available in 50W and sometimes 35W

12V Halogens are available in 20, 35 & 50 W and are more happy to be dimmed

GU10 lamps don't like being dimmed and dimmers have to be de-rated usually.

If you buy 12v kits- seperate tranny, lamp and fittings they don't work out much dearer over the medium - long term, also if you refrain from buying tat they will last a long time

 

[rustus]

What would be the correct size of 2-core flex to use for the final connection between the transformer and the lamp connector block in a 12v 35W per lamp setup, please?

Cheers.