Magnetic base LED machine light - WARNING MAY BE UNSAFE

Exactly what I found with mine! At least they're consistent. ISO9000 (or whatever) would be proud of them.

Hi Duncan,

Your modification pretty much eliminates the mains risk inherent in the lamp as bought and I'd be happy to use it as is. So we're only worrying about the possibility of a low voltage short in the goose-neck if your lamp happens to have the same fault as suspected in MikeP's unit.

Where the fuse or fuses go depends on how your 40V stepper supply is configured. If you have a voltmeter, all you need to do to find out is to check if there are any volts between the machine ground and the plus and minus 40V stepper power wires.

If the 40V+ wire shows volts relative to machine ground, you need a fuse in the positive wire.

If the 40V- wire shows volts relative to machine ground you need a fuse in the negative wire.

If both + and - shows volts relative to machine ground, you need a fuse in both wires.

If neither shows volts relative to machine ground, the one fuse should be fine.

Does the Duffer know what he's talking about? My understanding comes from a lifetime interest in Amateur Radio where there are different earth requirements for Radio Frequencies, Mains Safety, lightning protection and signal isolation. Professionally I know a bit about electrical practice in computer rooms and data centres but note all that's theoretical and not particularly deep. Therefore I'm quite happy to be corrected about the advice I offer - several people on the forum are better qualified than me.

Cheers,

Dave

A while ago, I was responsible for buying sub assemblies from China, to go into our light sources. I requested several samples to supply to a CE "Test House". The Chinese manufacturer said "Why bother?. I can supply modules with any certification that you might require" On checking this statement I realised that I was being offered a CE mark on the product, without any testing being done!

So beware of any CE mark on Chinese products that are imported directly from China or Hong Kong!

Andrew.

I can second that - our firm purchased a heat press from a so called reputable supplier the heater was 10a 240V - this heater had a centre tap with that cable cut off about 1/4" short of the metal plug with an earth cable connected to an isolated control box - the rest of the machine became live - I condemned the machine ended it's very short life in the bin CE just stood for China Export

Edited By Limpet on 29/11/2016 20:58:48

A lot of 9oimported model engineering kit is CE certificated by the manufacturers properly, although I don't deny there is stuff that is just marked 'CE', especially cheap grey imports.

My understanding is that it is the responsibility of the importer to do the CE compliance stuff, and he cannot sub it onto the manufacturer, see thread under LED fluorescent tubes

It depends whether they simply import or they rebrand. If they rebrand, they need to have their own compliance file.

.Gov.uk says "If you are importing a product that is from a third country you have to check that the manufacturer outside the EU has undertaken the necessary steps. " which is basically checking their doumentation, not re-doing the compliance testing.

Edited By Neil Wyatt on 29/11/2016 23:53:22

Even when done "properly" it only means the supplied samples were up to the required standard. As time goes on through the production run, "quality fade" is common Chinese business practice where materials and processes are cut back gradually gradually so they can make a profit on their low quoted production price. It's so common that whole books have been written on the practice. The Chinese, however, say it is not "quality fade" but "oversight fade" as Western customers turn a blind eye to quality as time goes on and focus only on keeping prices low.

I'd better check all my laptops, routers, games machines, iPhone chargers, TVs, domestic appliances, audio equipment, light fittings etc, given that the vast majority are made in China. Without wishing to generalise of course.

Not at all. The importer is responsible for ensuring that all relevant EU Standards are complied with on a continuous basis and for ensuring that the products are correctly marked. Of course things may change after Brexit and quality is likely to fall.

(Now ducking to avoid the flack )

Incidentally, I've seen many items which arrive CE marked but which are not subject to any Directive requiring CE marking. That is also an offence.

Russell.