Philips Lighting Singapore - Road & Area Lighting


Road & Area Lighting

		Road-lighting demonstration showing two approaches to energy saving: 2 normal lighting reveals object in road; 3 switching off a luminaire can make the object invisible; 4 with dimmed lighting the object remains visible

The function of road lighting When thinking of road lighting, we tend to think first of motorways. But road lighting covers a wide range of big to small streets and roads within the built-up area of our cities and villages. Its most important function, of course, is to provide safety for the road user, especially within the municipal boundaries where busy mixed traffic, in particular during the rush hour, makes high demands on lighting. Outside the municipal boundaries, where the speed limits are generally higher, the guiding function of a series of light points contributes to a considerable extent to road safety. In the quieter residential areas, the safety of people and possessions plays an increasingly important role. Here we see that the residents are having an ever-greater say in choosing the street lighting. In lighting, as everywhere else in our society, the comfort aspect is becoming more and more important. For instance, orange low-pressure sodium light is replaced more and more by the golden-yellow high-pressure sodium light, and in an increasing number of places white light also makes its appearance in the technical road-lighting segment. Increasingly higher demands are made on design, and on the materials used. Examples of this are the use of stainless steel for lamp posts and the increase in the use of coloured posts and luminaires. But road lighting has some additional important functions, such as improvement of orientation for people in unfamiliar surroundings, lighting of road signs, and support for road works. The general tendency towards higher quality luminaires plays an important role, in order to be able to guarantee better service to the public. Here we see that new technologies also stimulate new developments. New technologies Tele-management Tele-management comprises an individual profile with which a random light point is controlled in time, there is instantaneous feedback of various types of failures and, on the basis of collected data, there is optimum management of operation and maintenance of the complete lighting installation. Lamps Far-reaching developments are also taking place in the field of lamps. In the high-pressure sodium technology, the SON-T PIA generation meant a breakthrough in the field of efficiency, reliability, and lifetime. For the same reasons, QL Induction lamp technology is becoming increasingly important in public lighting. This trend is stimulated by the fact that with the QL family, Philips has at its disposal a wide range of wattages and consequently, luminous fluxes, various colour characteristics and extremely long lifetime. This meets the growing need for light sources that have not only low initial costs but that are economic throughout their life. This, in combination with high quality and reliability properties makes better service to the public possible. Ceramic Discharge Metal-halide technology, in the CDM Mastercolour technology, is also becoming more important, particularly in places where colour impression and colour rendering are more important than lifetime and optimisation of cost of ownership. Ballasts Breakthroughs can be expected in the field of ballasts for high-pressure discharge lamps. The new electronic ballasts for SON lamps are only interesting for the time being in combination with tele-management or in places where irregularities in the mains voltage lead to early lamp failure. Expectations are, however, that in the course of time the same development will take place for electronic ballasts for high-pressure discharge lamps as for fluorescent lamps. LED lighting The developments are extremely rapid in this field. There are already many systems in the market for orientation and signalling lighting. Expectations are that within a few years LEDs will be able to compete with the traditional public lighting systems. The word systems is used consciously here, because this new generation of light sources requires completely new luminaires and supplies. The first versions for public lighting are expected in the coming years. Here, too, lifetime is the most important factor. Dimming There are many reasons not to light more than is strictly necessary. Energy costs money and unnecessary use leads to extra emission of greenhouse gas, and light pollution. Although public lighting consumes only a very small part of the total energy requirement, it is a very noticeable part, and therefore has the constant attention of the public in debate and in political decision-making. The methods that were used originally, such as switching off individual light points or groups of light points lead to undesirable and even dangerous situations (figures 2-4). In many cases, block dimming proved not to be flexible enough, also because different types of lamps and applications (e.g. signpost lighting) were incorporated in the same block. Many of these original solutions are therefore no longer in use. It has become clear that successful use of dimming is only possible when every light point is operated individually. This is possible with a dimming switch, controlled via a pilot cable. For existing installations this can be a problem because there is often no pilot cable. Recently, Philips has marketed an extremely practical solution in the form of Chronosense. With this system, each light point can be dimmed according to an individual program by means of a tapped ballast, without the need for a control signal. HPL and SON lamps up to 400 W can be dimmed individually with this system, without the need of a clock, a cable, a transmitter or other controls. The energy consumption of every light point can also be rationalised individually in a flexible way by means of tele-management.