Technical

Technical

Why bother to rewire an American light fitting?!

ln my post The regulations that lights in Europe must meet (click here), I point out that there is more involved to convert a north American light for use elsewhere in the world than just "rewiring"! If a light is to be used in the EU, it has to meet EU standards, proof of which is given by a Declaration of Conformity, that you can request from the supplier at any time.

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Technical

The regulations that lights in Europe must meet

Many products sold in Europe have to be assessed to meet high safety, health and environmental requirements. So that you know that a product you are specifying or buying complies with all the regulations relevant to it, the CE logo (above) will be prominently located.

Of course, an immoral supplier might put the CE mark on, even though the product does not comply. So a Declaration of Conformity ("DoC") will always be available. Often in the box, it can also be asked for in advance so that you know that what you are specifying complies.

The maker can self-certify (i.e. it is not necessary to use an independent laboratory), but their Declaration of Conformity MUST be supported by the test data. You won't need to see them: they are kept on file in case law enforcement, trading standards or customs authorities ask for them.

The DoC will unambiguously identify the specific model. It will show the name and address of the maker. The particular harmonized standards with which it complies are indicated, and it is signed by a senior representative of the maker.

The harmonized standards potentially relevant to a light are:

-    for safety: for mains powered lamps, the Low Voltage Directive ("LVD")

-    to prevent interference with other electrical equipment by control gear or electronics in the light: the ElectroMagnetic Compatibility Directive ("EMC")

-    for EcoDesign: the Energy Related Products Directive ("ERP")

-    energy labelling*: this, for example:

EU energy label

-    to control hazardous chemicals: the RoHS Directive (Restriction of Hazardous Substances) and the REACH Regulation* (Registration, Evaluation, Authorisation and restriction of CHemicals)

-    to prevent waste: the WEEE Directive* (Waste Electrical and Electronic Equipment); for batteries, Directive No. 2013/56/EU*; and for all products, including packaging, Directive No. 94/62/EC*.

*not applicable to CE marking

EN60598

The core requirement of the Low Voltage Directive is that products must be safe. Compliance is demonstrated by meeting the harmonized European safety standards. For lights, this includes EN60598. It is in two parts. Part I applies to all lights, and is 216 pages long. Part II is in twenty three sections, each one dedicated to a particular type of light (e.g. "portable general purpose luminaires") and adds requirements specific to it.

EN60598 goes into great detail about: methods of construction; wiring; earthing; protection against electric shock; resistance to dust, solid objects and moisture; insulation; resistance to heat and fire; and terminals; amongst other things.

There is a section on marking that defines not just what information should be on the light, but also where it should be put, so that it is seen when it is needed. It includes the CE mark, the name and (from April 2016) the address of the maker, the model name, and details of the lamp types that can be used. So if you can't see this information, you already know that the luminaire does not comply, and in the most obvious way! Don't use it. Send it back.

It is no good making a light and then reading the Directive to see if it complies. It won't (there are too many details). Instead, read it first and see it as an invaluable, very specific indicator of what you have to do in order to create a luminaire that is safe – and that could be proved safe in court.

The extraordinarily good thing about EN60598 is that, if your light complies, it can be sold all over the world, except north America! For it is based on the global standard IEC60598 (IEC = International Electrotechnical Commission). There are necessary minor differences between states (e.g. the fused plugs required by UK electrical wiring practices) and these are included in the text of the Directive.

Note, though, that the standards in north America are completely different, which is why lights made to American standards cannot be used elsewhere in the world, and vice versa. As you can now appreciate, a lot more is involved than just "rewiring"! Please read my post Why bother to rewire?!here.

WHY DOES ALL THIS MATTER TO YOU?

If a light does not comply, it is illegal and potentially dangerous!!!

Whether you are a manufacturer, a retailer or a specifier, it would be unprofessional to make/sell/specify anything that is illegal and potentially dangerous.

And it would say something unpleasant about your attitude not only to your customers, but also (bearing in mind the environmental requirements) to the planet.

If you ran a restaurant, would you do nothing about the rats running around its kitchen? And how do you think your customers would feel if they found out about them? Or if they died (a faulty light can kill; a rat just passes on diseases).

Note that there are no exceptions. If you only make/sell/specify one light, it must still comply, even it is a "work of art".

And ignorance is no defence. It is clear that some makers have never read the standards (whether they think they comply with them or not) and the syllabuses for training interior designers do not cover the law as it relates to what they specify!

So, specifiers and retailers, ask for the Declarations of Conformity. And, makers, there will be a professional association in your country specifically designed to support your ability to comply. In the UK, we are fortunate to have the Lighting Industry Association ("LIA") and its Laboratories.

Finally, to keep this post short, note that many of the statements above are over-simplified.

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Information, Technical

Specials: if I want my light twice as big, will it cost twice as much?

surface of a sphere

No. It will cost more than double. Why?

1.        The increase in the quantity of the raw materials used will be more than double.

Suppose your light is basically a sphere, like these Hellbobs from Windfallused in this interior designed by René Dekker:

Windfall Hellbob chandeliers René Dekker

The size would be given by the diameter -- you'd say, "I'd like one 90cm in diameter". But the quantity of materials used -- the crystal components and the metal, in this case -- is determined not by the diameter but by the area of the surface of the sphere. If you double the diameter, you more than double the surface area of the sphere.

At school, you learnt that the surface area of a sphere is given by the formula 4πr². The radius is half the diameter, so doubling the diameter doubles the radius.

But there are those other factors in the formula. So, for example, if the radius is 50, the surface area is 31,429 (50 x 50 x 22 ÷ 7 x 4). But double the radius to 100, the surface area becomes 125,714 (100 x 100 x 22 ÷ 7 x 4), which is not double, but four times the original area.

2.        The unit cost of the raw materials and components will be higher

It takes on average two years for a lighting maker to bring an original concept to market. Many processes are taking place during this time, that are concerned not just with its design, packaging and pricing, but also with what it will be made from, which subcontractors will be used, and how it will meet the relevant regulations (the main one of which -- IEC60598 -- is 192 pages long in its English version).

The prices of raw materials and sub-assemblies of the standard items are therefore tightly controlled. But a special undermines all this work.

The larger the stock order is of, say, crystals of a particular type, the cheaper they will be. But, if the maker has to buy in a small quantity of something they don't stock, the unit cost will be higher.

Some items -- for example, fabric covers for cables  -- can only be bought in minimum lengths, which could be a kilometre. So, if only 1m is required for your special, they still have to buy 100m.

3.        You can't expect people to work for nothing

Once a catalogue item is launched, pretty much everything has been worked out. Issues will come up, of course, but there will be standard computerized systems controlling the stock, subassemblies and manufacturing. Packaging is designed and sitting on shelves. The light meets all the regulatory requirements.

As soon as we ask for something different, however, a miniature version of all the work done for the catalogue item has to be done again. The implications of the modifications have to be identified and designed around. Greater weight may mean that the suspension components have to be changed and other modifications made so that the tilt tests are passed. Once quantities have been calculated, suppliers and subcontractors have to be negotiated with, specifically, and only, for the special.

The modified version has also to meet all the regulations.

Only highly skilled people can take care of all these things.

And they are not sitting around doing nothing, awaiting our email. They may have other work to finish before they can look at our special. So might the subcontractors.

Then, making the special has to be scheduled through production. Not only has a window to be found for it, but it will take longer than a standard item and may need to be done by the most senior operatives. They will have to wait until the special parts have been delivered and tested.

So...

...no. It will cost more than twice as much. And you will have to wait for the experts to design and cost your special. It will also take longer to make.

Conclusion:

Always specify a standard item if you want to keep the cost down and if you want a price quickly!

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Technical

WHY LIGHTS SHOULD NOT BE PUT IN THE CEILING!

There are many obvious reasons why lights should not be put in the ceiling -- the unpleasant effect of hot bright light drilling into the top of your head, the inability to move them, problems when they stop working, fire, raking shadows, the "architect's grid" or "ceiling acne" when downlighters are arranged so as to provide a flat hard light that ignores what is being done in the room, and where. To name a few! But the most compelling reason is environmental.

Illuminance obeys the inverse square law: the quantity of light varies inversely with the square of the distance between the source and the surface receiving its light.

So, if the light source is moved three times further away from a surface, nine times as much light is needed to achieve the same lux level on that surface.

Put another way, a light source on the ceiling, 210cm from the table top, uses NINE TIMES as much energy as a light source 70cm from the table top.

 

Therefore, by putting a light in the ceiling, you are putting it as far away as possible, and so maximizing the waste of energy.

That it is always possible to put the light somewhere suitable is proved by this picture:

This is Album's unique Radiale system. They provide a selection of (beautifully designed) lighting bodies that perform all the major functions -- radiant, spot, task --, all of which you can see being used properly here. The concept is simple: each lighting body is attached to a long thin cable that goes back to an elegant transformer (in the shape of a disc) on the wall. They also supply a hook on the cable so, by screwing the hook into a suitable location, the light can hang down exactly where it is required.

In this particular location, their system also provides light at night to replace the light that comes from the skylight during the day, without blocking the skylight. (By the way, they are also one of the few decorative lighting companies to be creating really excellent LED lights.)

Of course, there are situations where it is appropriate to put a light in a ceiling. A good lighting designer will position light sources where they are required, always driven by what is being done in the space, and where.

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