Sparks Electrical News August 2021

LIGHTING

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lamp in combination with each dimmer in the mar- ket is “an impossible task” for both lamp and dimmer manufactures. “The old electronic transformers for halogen down- lights are a case in point: those transformers have been in the local marketplace since the early 1990s but there is still no official IEC standard for transform- er-dimmer combinations.” Shuttle Lighting Shuttle Lighting’s response to the lack of specifica- tions is to conduct as much testing as possible, on as many LED lamps as possible. “Where clients experience problems with lamps un- known to us, we will acquire such a lamp and charac-

terise it. We also publish a compatibility chart so that, should future problems occur, we already know how the lamp performs under lab conditions.” The com- pany stocks a comprehensive range of dimmers, both for sale locally and for export to Australia, Europe and the UK. Each of these dimmers bears local and Euro- pean certification. “Our core business is not lighting per se; we don’t supply lamps but it is our mission to serve all lamp providers and contractors – we solve problems by means of innovation and solutions development.”

Looking at that kind of innovation, it seems that the lighting industry may be on the verge of another solid- state revolution, this time in the motor industry.” Human-centric lighting Halogen and incandescent lamps essentially produce light by igniting an inert gas contained within the lamp, making their light quality similar to that of the sun. Smit says their colour temperatures can be adjusted to mimic sunlight at different times of day, and so en- able human-centric lighting, which is beneficial to hu- man health. This, however, requires dimming since the colour temperature on halogen and tungsten lamps changes when these lamps are dimmed. “With LEDs, the colour temperature remains un- changed upon dimming while a halogen lamp pro- duces warmer light as it is dimmed.” He says it has therefore become common practice for LED suppli- ers abroad to include LEDs of varying colour tem- peratures in specialised lamp modules. An example is Signify’s DimTone lamp range. Smit sees human-centric lighting as one of the “next big developments” for the user, even though the added LED components in these lamps make them more expensive to purchase. “I predict major growth in this area. We already have LED light panels where you can physically set the colour temperature so the user can enjoy cool, white light in summer and warm light in winter, for instance. The contractor, too, benefits as he or she only need to supply one product which offers the client multiple options.” He says the design of LED lamps is becoming a “fashion item” but that the long lifetime of these lamps and advances in technology are causing sup- pliers to introduce lamps in new forms and shapes “virtually every six months”. “The problem is that lamps of a certain look and specification are specified for building projects but, by the time the project is completed a year later, the specified lamps are no longer available in the mar- ket.” ‘Auxiliary’ technologies The electronic nature of the LED lamp allows for the inclusion of ‘additional’ technologies such as oc- cupancy cameras and ‘light fidelity’ (LiFi), where en- coded, unobservable flicker communicates data to mobile devices, much like WiFi. However, Smit views these added functions as a “concern” in terms of industry specifications: “The dimming levels of the countless LED lamps in the market are not standardised as we still have no IEC or EN specification to determine how lamps should function in conjunction with dimmers.” He concedes that the US National Electrical Man- ufacturers Association (NEMA), an organisation of large LED suppliers, has released the SSL6, SSL7A and SSL7B specifications for lamp-dimmer combi- nations, but notes that these specifications are vol- untary by nature. “If, after all these years since LED technology was introduced, there is still no specification for compati- bility between lamps and dimmers, it raises concerns when manufacturers include other technologies in their lamps. This lack of compatibility specifications poses a major problem, both locally and abroad.” He says Shuttle Lighting’s dimmers feature set- tings for minimum and maximum dimming intensity. In some lamps, minimum dimming intensity results in flicker, which can be remedied by increasing the dimming intensity slightly and setting the dimmer accordingly. “Filament LEDs are particularly sensitive to voltage fluctuations at low-intensity dimming and this creates headaches for the dimmer provider.” Industry specifications While compulsory specifications exist for LED lamps and for their controlgear respectively, Smit’s concern lies with the absence of regulation of lamps in com- bination with controlgear such as dimmers. “The reason could be that there are so many dif- ferent types of controlgear and dimmers. Producing lamps to comply with dimming curves would esca- late their cost, in which case the absence of regula- tion makes sense from the end-user’s point of view.” He says the specifications for dimmers alone are numerous and onerous, and that testing for each

Dr Marthinus Smit, director, Shuttle Lighting

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SPARKS ELECTRICAL NEWS

AUGUST 2021