Definiton of Double Insulated - Class 2

[Mike Hall]

We've just bought a bathroom wall light, (from Habitat), that claims to be Class 2 and specifically says that no earth should be attached. Looking inside I can't see how on earth (pun intended!) it can be double insulated, and I believe it will be much safer with an attached earth. The case of the light is painted metal, (aluminium), and inside there are mains votage wires. i.e. The separation between the mains voltage and the aluminium consists of the brown single layer of sheath around the cable and then the paint on the metalwork. Does paint really class as a layer of insulation for these purposes?

Anyway, not withstanding the above I'm going to earth the b*gger, especially as it's in a bathroom, which brings me on to the question of supplementary bonding. I know this is a well trodden subject in this group, but I still need a little clarification. The wall light is going to be wired in 1.5mm^2 T&E that I've burried in the plaster. I know it is permissible to use the CPC for supplementary bonding, so I presume this means that I am OK bonding from the JB in the loft, (that feeds this light), onto all of my other supplementary bonding?? Is the CPC in 1.5mm^2 suitable for this, as I've read talk of min 4mm^2 for supplementary bonding???

Finally, if I do have to run in a separate supplementary bonding right to the fitting, is this OK to run in the wall cavity, (as I forgot to plaster one in the wall!) - Hopefully this will be irrelevant anyway, as someone will tell me that the JB in the loft, being in 'close proximity' to the wall light, is a suitable place to bond to.

[Steven Briggs]

In message , Mike Hall writes

Generally paint & enamels aren't counted for safety grade insulation. I'm not totally familiar with the lighting equipment standards, but from your description is doesn't sound like the product qualifies as double insulated. If the insulated & sheathed mains wiring terminated inside some sort of plastic housing (i.e. a fully enclosed lamp base) within an otherwise metal case then OK, but if you're saying there are single insulated wires possibly in contact with the metal case, that sounds dodgy to me.

Yes you can do that.

4mm2 is the minimum where there is no mechanical protection, i.e. a simple single core wire.

The J/B is close enough.

[Andrew Gabriel]

I don't have the standards, but it was described on a course I did a few years ago. IIRC, two layers of insulation are required. One can be air, but something needs to ensure a suitable gap is maintained in this case. Unsheathed insulated conductors which can come into contact with exposed metalwork would not count as double insulated. Are you sure additional sleeving wasn't provided to slide over the singles (not that I'm sure if this makes any difference)?

[N. Thornton]

IME there are numerous items marked as double insulated which in reality dont meet Class 1 or 2 standards. I've heard it suggested that the extra insulation is included until production stage, when it is often dropped.

I couldnt trust [[]] marked goods to be upto standard without an inspection.

Regards, NT

[Steven Briggs]

In message , Andrew Gabriel writes

Yeah you could count an air gap if it was controlled (i.e. from a rigid component), but wouldn't count from uncontrolled wires. I've been trying to think if a seen anything similar to the OP's claim, the nearest is a floor standing up-lighter I've got, metal body, but double insulated two core feed, and the flex won't become un-sheathed until safely in the lamp holder. So OK. OTOH, I've had silicone sleeving provided with glass bowl type ceiling fittings to slip over the incoming leads, but I'm fairly certain they where earthed anyway and the sleeve was for high temperature protection.

Anyway, manufacturer's often get things wrong in production, particularly the guy who menial task is to do the labels. Start with a template label that has all approval logos & symbols, and forget to delete them.... Not of course that I've seen product go out the factory with illicit logos on labels, oh no ;-)

For the OP, was there any provision to earth the metalwork anyway ?

[Dave Stanton]

And most of this sort of stuff appears to come from our friends in Europe !!!

Dave

[Mike Hall]

No... not yet, but after a bit of work with a drill and a nut/bolt/shakeproof washer there sure will be!

[stefek.zaba]

That's the spirit ;-) As I think I mentioned a couple of months ago, I had a similar experience with some IKEA lights - five golfball lamps in a row with shiny pressed-and-folded sheet metal backing. It claimed as yours to be double-insulated and suitable for bathroom installation (in my case one each side of a mirror above the sink, well out of reach of the shower but still within a should-be-bonded Zone), and may even have met the letter of that spec (though I wasn't that convinced by the details of the cable routing). A few moments with a drill, nut-bolt-shakeproof to hold down a ring crimp on the end of a handy length of green-and-yellow, and once again Robert is a sibling to your parent...

Stefek