Wiring advice please for GU10 light fitting

[Simon]

I'm replacing GU5.3, 12V ceiling mount halogen lights (separate 240V to 12V) power supply) in the kitchen with GU10, 240V, 5W LED types (240V power supply built into the LED bulbs).

There is the usual grey sheath twin and earth to junction boxes above the ceiling.

The steel ceiling fittings of the new units (fire rated) have a 3 terminal chocolate block mounted on a metal strip to connect to.

A colleague states "this is permanent wiring, so should use the grey sheath twin and earth from the junction box to the ceiling fitting". Interestingly, the previous halogen units had very thin (2 wire, no earth) flexible cable from the junction box to the separate power supply - no earth for the steel housing.

I'd rather connect with 3 wire flexible cable of reasonable guage from the junction box to the chocolate block on the ceiling fitting. (It just works out easier for me). But if that's a no-no, I will use the grey sheath twin and earth.

Comments please. Thanks in advance, Simon

[On a separate, but related point, I read the EU is going to ban 12V halogen lights. I don't usually agree with the EU regulating us, but this time I do. Reasons:

1. Extreme inefficiency of the 50W 12V halogen lights = energy waste. I find the 5W LED lights have comparable brightness.
2. This leads to extreme heat, which is a danger. (A few minutes of lights on, and they are untouchable for a long time.)
3. The high current (50W/12V = 4A) leads to deteriorating bulb-holders, wire and intermittent connections. That's an observation as well as opinion. ]

[Tricky Dicky]

It is quite normal for mains spot light fittings to have T&E run up to a ju nction box and then use a short length of flexible cable to make the final connection to the lamp fitting, and you are correct the fittings should be earthed. It is advisable to use heat proof cable for this final connection, although your LED lamps will not generate much heat if someone replaces a bulb with a standard halogen GU 10 then that will generate heat.

Richard

[John Rumm]

Since they would have been classed as SELV, they would not have needed earthing.

1mm^2 T&E would be fine - easy to work, and will fit the terminals.

Depends on how you look at it. 12V filament lighting has greater output (lumens per watt) than 240V lamps...

It doesn't if you measure with a lux meter. A 9W LED GZ10 replacement will give a similar output to a 50W halogen, although in a slightly narrower beam.

Its only a danger of the fitting is not designed for this, or it is located in a daft place.

When combined with a low standard of workmanship - connections can be a problem. I have not noted any deterioration in bulb holders on my 12V lamps though.