CE (CONFORMITE EUROPEENNE in french) is a mark which all the products placed on the EU market need to have. This also applies to street lamps, but also to all the components they are made out of. In order to allow the import of certain goods in the EU, it is necessary that the manufacturer provides a CE Declaration of Conformity, but also the importer and distributor in the EU must provide the same kind of CE Declaration of Conformity too. For such a statement to be valid, the provider of that statement should have the so called “Technical map of the product”, which means the list of all the components, and make all the certificates and tests for all the components and test reports of the product itself. You can not absolutely trust the CE Declaration of Conformity given by the distributor, the importer and not even by the manufacturer, because you need to be careful as to whether all the neceessary tests for CE compliance of the product were carried out and, if so, whether to believe them or if they were carried out by accredited body and laboratory. Therefore, careful client won’t look for CE Declaration of Conformity, but for the CE Certificate of Conformity issued by the accredited laboratory and body, and accredited for testing according particulary to standards that are required in order to determine the CE compliance of the lamp.
ENEC (European Norms Electrical Certification) is a voluntary mark which designates the products, agreed by accredited bodies just within the EU. This mark means that one of the bodies accredited in the EU confirms that the product has passed all the demanding tests in terms of safety and quality. The mark is given for each product that receives it, and the licence is renewed annually and tests are carried out on a random basis. What is important for the customer is that the production takes place under supervision, because the production is licensed, so as to ensure that the hundredth product in sequence has the same features and quality as the first one which has been initially tested.
The dimming ie. the regulation of the luminous flux is often used. That is done by reducing the power of the LED light source so it emits less light output.
By using dimming 20% -30% of the energy can be saved, all depending on the method and the mode of dimming. Typically, the dimming is set to several power levels – 3 to 4 levels, when in the late night hours power is reduced gradually to 50%, and it is increased towards the morning to 90% or 100% power.
It is important concerning the safety of the traffic and general atmosphere that the luminous levels are not reached at once and suddenly, but that the power reduction to a lower level (or increase to a higher level) is done using a continuous linear model trough a shorter time period (eg. 15 or 30 minutes).
However, one should be careful and reasonable when setting the dimming. The public lighting is designed so that it meets the light technical standard EN 13201, and lumination requirements for a certain road class. It should also be remembered that, when the power is reduced to half, the road is not illuminated to the lower class, but very likely to no type of class. Therefore it should always be the decision of the public lighting operator.
Good practice is that the decision is not made generally, but on a case to case basis.
LED light source (LED) is such a component that actually, as such, it does not burn out, so it theoretically has a very long lifetime. Only the amount of light output which it emits will decrease over time. The human eye does not register the reduction of light up to 70% of the initial luminous flux. For these reasons in the LED technology it is considered that the lifetime of a LED light source is such the time as needed for the luminous flux to decrease to 70% of its inital value.
Widely commonly used standards and methods for the testing of LED light sources are prescribed by the American organization IESNA. Thus, LED sources are tested for aging and cromacity color loss according to the standard IES LM 80-08. For the loss of light emission over time the prescribed number of samples are tested and for at least 6000 hours. The results are forming a curve and it is noted where it intersects 90%, 80% or 70% of the nominal light emission over time. However, the curve defined in this manner usually intersects the point of 80% of the nominal emission of light at a point above 200,000 working hours. This is completely unrealistic so the method for declaring lifetime is added to this standard and this is the method according to IES TM 21-11. According to this method the lifetime can be declared only six times (or five and a half times if number of samples is less than 20) of the time of test running. This means that for the minimum 6000 hours testing, only 36,000 hours can be declared as the life span. For 10,000 hours of testing a lifespan of 60,000 hours can be declared, and only for 16,700 hours of testing the lifetime greater than 100,000 hours can be declared. It is therefore necessary to ask for the test report and see how many hours the LED light source has been tested.
Cautious client will not accept the declarations from distributors, agents or branches, because employees there usually are not very familiar with the details regarding the components used in the lamp. Therefore, careful buyer will request that the technical characteristics of the lamp are confirmed by the lamp manufacturer which is as such on the certificates issued by accredited laboratories and bodies.
Yes, the EMC test is required for each driver used in the lamp family, as usually in the same lamp family different drivers are used for different system power options, all because of work efficiency. It is not enough that the driver itself has EMC test, because by installing it in the lamp that kind of circuit can generate electromagnetic interference so the lamp has to be tested in working conditions.
ESCO is a model that is defined by our legislation as an energy service. Energy service is neutral for the budget of the local government, as the payments to the provider of energy service are made only up to the amount of proven and verified energy savings. The funds for electricity are planned in the budget as they were before, out of which the new reduced power consumption is paid and the rest is the saving that is to be paid to the provider of energy service. This is per provisions of the Energy Efficiency Act (NN 127/2014) and the Regulation on the negotiation and implementation of energy service in the public sector (NN 11/2015).
In energy services, after the implementation of energy reconstruction ie the reconstruction of public lighting, the client has new lamps and even more, because they are new, he will not have maintenance costs. In addition, LED lighting fixtures have a very long lifetime. The declared lifetime of LED light sources of 100,000 hours means in fact 25 years of work. And good drivers have a lifetime of over 100,000 hours so that there is really nothing to be maintained. However, despite all the declared longevity of the lamps, it is realistic to expect a small percentage of disfunctionality in the actual operating conditions. Therefore, the energy service is suitable for the client, as it will require the provider of energy services to keep under warranty the functionality of installed lamps for the entire duration of the contract. During this time the client will have approximately 90% lower maintenance costs than before the implementation of new LED luminaires. Regular maintenance at the expense of the client will only apply to cables, fuses, cabinets and light poles.