No earth wire!

[kosmonooit]

Thanks Dieter I am just quoting 'the book' having made an attempt to memorise it, and the subject of earthing lights did come up for discussion in our classes at P&T.

I have been doing domestic LED conversions using those GU10 fittings from those horrible 12V transformers that sit it the roof. Those things are a real fire / safety hazard, the get so hot the melt wires and fittings (see pic). Have seen some that are earthed, others not, but never the fittings as such. One does get a GU10 adapter with provision for earth, but if the fitting is non-conductive, there is no point really?

[AndyD]

I'm not getting confused with discharge luminaires....well not as far as I know at least.

My understanding is that generally a 'lamp holder' is not a 'luminaire', it's a part of the luminaire that the lamp actually inserts into. These are lamp holders;

The only time a lamp holder on its own would qualify as a luminaire would be if it would fall under the note in the luminaire definition in 3.48.

NOTE A batten lamp holder or a lamp holder suspended by a flexible cord is a
luminaire.

I don't see that reg 6.14.4.1 would extend to the entire 'luminaire' or 'light fitting' unless it was a batten lamp holder suspended by flex. Therefore there's no way a luminaire or light fitting would be exempt from earthing.

Reg 6.14.4.1 A lamp holder shall be shrouded in insulating material or shall
be earthed, unless it is simultaneously
a) out of arm's reach from the floor or walkway level,
b) out of arm's reach from a structure that is bonded to earth,
c) protected from the weather and the splashing, dripping, or accumulation
of water, and
d) not touching a conductive surface.

A luminaire or light fitting is the complete lighting assembly including the lampholder inside obviously. Luminaires;

According to the regs the definition is;
3.48 luminaire
appliance that distributes, filters or transforms the light transmitted from
one or more lamps and that includes all the parts necessary
supporting, fixing and protecting the lamps but not the lamps themselves,
and, when necessary, circuit auxiliaries together with the means for
connecting them to the supply.


To address the exception made for an 'exposed conductive part' in 6.12.3.2. I'd suggest 'exposed conductive part' would apply to exposed cover screws for example. Any part likely to introduce any potential, including earth potential, would be classed as 'extraneous conductive' and not 'exposed conductive'. For the part to qualify as exposed conductive it would need to have a resistance of at least 1kΩ @ a 250v IR test in dry conditions otherwise it would be classed as extraneous conductive in which case it should be earth bonded.

[bergie]

6.12.3.2 The following conductive parts do not need to be earthed:

b) exposed conductive parts of fixed electrical equipment that are
1) out of arm's reach from the floor (or walking) level,
2) out of arm's reach from a structure that is bonded to earth, and
3) not exposed to the weather or to the condensation, dripping,
splashing or accumulation of water, and
4) not touching a conductive surface;

and/or

6.14.4 Lamp holders


fixed electrical equipment : would a luminaire not be considered fixed electrical equipment?

[Dave A]

Here's one I got presented with this morning.

It is a low hanging Radiant light fitting with metal ceiling cup and reflector/shade over a kitchen counter top -



The bottom of the metal reflector is 1.8m above floor level. It's a 220v luminaire. Our test for earth on the metal reflector revealed no continuity back to the main earth point of the installation. Closer examination reveals there is an installation earth conductor available at the point of consumption, but no earth connection point provided to connect to within the luminaire, and the cable between the two metal parts is twin flex with no earth conductor.

Ultimately the luminaire seems to be installed and connected as designed...

Thoughts, anyone?

[Leecatt]

Well now I can't find the sentence in the regs.
It used to say that a tool must be used to separate connections, or something to that effect. Of course, undoing a twist tie is not using a tool. I will keep looking when I get more time.

[Dave A]

Nice picture, I assume that you do realise that the use of "twist ties" is also illegal.

Care to elaborate on that? I am just asking because when i got the contractor in to replace all the lights in my home, "twist ties" was the norm" They are all gone now but somehow the guy that did the first COC didn't mention it and he cost me a lot of money to date and I would love to know more because this will be yet another thing he overlooked.

Well now I can't find the sentence in the regs.
It used to say that a tool must be used to separate connections, or something to that effect. Of course, undoing a twist tie is not using a tool. I will keep looking when I get more time.

I'd also be curious as to the section that makes the twist tie illegal on all phase conductors and neutrals.

When it comes to the earth conductor,

6.12.1.5 - Connections of earth continuity conductors shall not rely only on twisting of the conductor or strands of the conductor

and

6.12.1.6 - A fuse or switching device shall not be fitted in an earth continuity conductor (joints which can only be disconnected by means of a tool may be provided for test purposes).

apply.

[SilverNodashi]

Here's one I got presented with this morning.

It is a low hanging Radiant light fitting with metal ceiling cup and reflector/shade over a kitchen counter top -



The bottom of the metal reflector is 1.8m above floor level. It's a 220v luminaire. Our test for earth on the metal reflector revealed no continuity back to the main earth point of the installation. Closer examination reveals there is an installation earth conductor available at the point of consumption, but no earth connection point provided to connect to within the luminaire, and the cable between the two metal parts is twin flex with no earth conductor.

Ultimately the luminaire seems to be installed and connected as designed...

Thoughts, anyone?

So it shouldn't be earthed?

[hartdev@hotmail.com]

I struggle to understand why any light fitting out of arms reach should not be earthed. If someone is on eg. a metal ladder and gets a shock while changing a bulb or doing a repair then that person could fall from a height as a result, making it more dangerous than something that is at arms reach.
It's not like it's a big deal to connect an earth wire...