Metal Desk Lamp - Wiring/compliance

[Greenwich Junky]

Hello, I am building a metal desk lamp out of old iron piping.  It looks good but I am concerned about the wiring.  I have found a supplier for a metal bulb holder which has a threaded end to screw into 20mm piping.  As the fitting is metal they say it requires 3 core fabric lighting cable (which they also supply) because it requires earthing.  I understand the need for this and, in fact, the whole light is going to be made out of metal so from what I understand it definitely would require an earth 3 core cable.  The company supplies the bulb holder fittings already wired up to 2 core cable but not 3 core.  This makes me nervous.  Does anyone know why they are happy to wire up 2 core but not 3 core to the light fitting?  They say it is just not something they do.  Is this a job I could do myself or do I need an electrician.  Presumably once the wire is attached to the bulb fitting, I thread it through the metal piping and I just need to add a plug.  I would be grateful for any comments if anyone sees any problems here such as do UK regulations require a switch? or can I just use the plug socket as the switch and if I do need a switch, is that easy enough to incorporate using fabric cable?

Once the light is constructed, it is my intention to have it checked by an electrician before switching it on!  Can anyone recommend a reasonably priced company for small quantity electrical and EU compliance certification (preferably London so I can visit in person).  I have found some online but most cover large suppliers.  

Many thanks in advance for assistance.

Fiona.

 

[Andy™]

that kind of work is not covered by wiring regulations, and there are very few people here who could even give an 'EU compliance certificate'.  and for a one-off, it would probably be very expensive

if the lamp holder is 2 core then its probably designed for to be double insulated. in which case the metallic pipe may not need an earth

 

[Pepparz]

use 3 core 1mm² flex and earth the metal base using a brass screw and bolt or similar and a 3 amp plug top fuse, make sure the cable wont chaff on the pipe, job done.

 

[ProDave]

For one off prototypes you don't need CE marking.

Just build it, earth the metal frame, and get is PA tested as a class 1 device.

 

[SLIPSHOD & SLAPDASH]

Where in London are you ?

Edit, Greenwich, too far from me.

 

[Sidewinder]

For one off prototypes you don't need CE marking.

Just build it, earth the metal frame, and get is PA tested as a class 1 device.

Unless you are putting it into your business for business use, then you must comply with any and all legislation, standards etc, even for prototypes.

 

[Greenwich Junky]

Thank you, yes, I expected that I would need to get it certified as safe and compliant.  I would like to sell them in the future and so the design needs to be compliant.  Does anyone know of a company that provides electrical design consultancy services that would be interested in this initially small job.  I found a couple of firms via the internet but so far they are not interested in this relatively small job - they seem a bit unimpressed that it is a desk lamp and not a office block IT system!  Fair enough.  I realise it will cost a bit but I was hoping in the hundreds, not the thousands.  I can make it look cool but at the end of the day the electrics need to work... and safely!

Many thanks.

Fiona.

 

[Sidewinder]

You can CE mark against the LVD etc. yourself, as long as you are competent to do so, and insured.

 

[Marvo]

If you're buying the lamp holders prewired then ask the company that's supplying them for the certification. As long as you don't change anything then that should be adequate. For example if the lamp holders are certified as a 'Class II' item you can extend this certification to your finished product if you don't make any electrical alterations or additions.  

 

[Sidewinder]

If you're buying the lamp holders prewired then ask the company that's supplying them for the certification. As long as you don't change anything then that should be adequate. For example if the lamp holders are certified as a 'Class II' item you can extend this certification to your finished product if you don't make any electrical alterations or additions.  

Really?

 

[Marvo]

Really?

Lol, I assume you disagree?

 

[Sidewinder]

I don't see how you can extrapolate CE marking from a single component/.sub assembly to a completed assembly, especially as it is specifically stated in all guidance issued in the EU for compliance with the LVD, the MD & the CEMD, that this cannot be done.

There is a saying CE + CE does not equal CE.

This is TOTALLY correct and true.

 

[Marvo]

What she's describing is a complete electrical assembly that will remain unaltered and will be put in a housing.

 

[SLIPSHOD & SLAPDASH]

I doubt the cable from the lampholder will be long enough or be able to go through the fitting  without modification.

 

[ProDave]

I would not personally be very happy using a class II pre made lamp holder with a 2 core flex, and then passing that flex through a non earthed metal tube (or tubes)

It sounds to me like the OP is re inventing the anglepoise lamp?

With regard to prototypes, in my last proper job we were always making one off experimental rigs and running them in the lab and nothing was ever certified, just basic common sense testing.  It was only when a machine went into production and got sold to a customer that we did all the work to CE mark it.

 

[Sidewinder]

With regard to prototypes, in my last proper job we were always making one off experimental rigs and running them in the lab and nothing was ever certified, just basic common sense testing.  It was only when a machine went into production and got sold to a customer that we did all the work to CE mark it.

Yes PD, you are absolutely correct, I don't think my terminology was quite right.

However, if the prototype makes it out of the lab and into your production facility, if you were self building say your production machines, then once it goes from the R&D dept say and into it's place on the shop floor in the production line, then it must be CE marked.

 

[roys]

 if you were self building say your production machines, then once it goes from the R&D dept say and into it's place on the shop floor in the production line, then it must be CE marked.

This is turning out to be an interesting thread and in a different way than I thought it was going to go,  so just to make sure I am understanding this correctly, if I make up say a shoe box size panel with a couple of timers, a couple or relays and a handful of SAK terminals all on a bit of DIN as an addition / modification to a bit of our production line, I would have to get this CE marked ( or should I say ' should have got this CE certified') ? 

 

[Sidewinder]

roys,

The answer is probably, but it depends, this could warrant a thread all of its own TBH.

Are you employed?

If so then the responsibility falls on your employer.

I'll see if we can get this hived off into another thread if you like?

 

[ProDave]

The fact of the matter it it's all irrelevant.

Conformity with all the various EU standards, be it low voltage, machinery etc, rests with trading standards to enforce.

So if you make one off, or a small number of machines and use them in your own factory, in the real world, nobody will give a jot.

Put them on sale with a CE mark on it, and nobody will give a jot, unless perhaps if one of them kills or injures someone, then they may take a closer look.

Do you REALLY think all those imports from China with a CE mark REALLY comply with all the EU directives and have the documentation to support them?  Are trading standards going to check them all?

When all this nonsense first came in, to start with we spent a lot of time on it, before drawing that conclusion.

Of course none of the above is to be taken as advice. but I'm not sorry to no longer be designing machinery. I used to love electrical design, but became to hate the paper trail you had to create to support anything you made.

the only time it DID matter, was one company I worked for, in a very cut throat business, would pull the competitors machine apart actively looking for non compliances and then reporting them, to try and make life difficult for the competitors and for no other reason.

 

[Marvo]

I would not personally be very happy using a class II pre made lamp holder with a 2 core flex, and then passing that flex through a non earthed metal tube (or tubes)............

Surely if the pre-assembled lampholder and flex assembly came with ClassII certification then the metallic housing of the lamp would just fall under the normal supplementary bonding regs if it was for domestic use? This is a question, not a statement, I genuinely don't know the UK regs so I'm interested what you'd be unhappy about.

I do have a somewhat unrelated but not completely off-topic query as well. If hypothetically speaking this lamp was being sold in the UK and it only had a single pole switch either as an integral part of the lampholder itself or part way along the trailing flex cable, would the lamp be compliant for use on installations that have a TT earthing arrangement? If not then as the manufacturer or supplier would you be required to state its unsuitability for a TT supply on the product or would it be the responsibility of the householder to establish whether the product is suitable before plugging it in?