The Electric Lamp and Component Manufacturers’ Association of India (ELCOMA) is spreading awareness about the benefits of LEDs through workshops, seminars and exhibitions, apart from coming out with an LED street lighting guide for everyone in the industry. It is also educating people about the hazards of buying low cost but unsafe lighting products. However, there is no mandate for quality standards or an environment for manufacturers to invest in the production of LED chips in India yet. The government must step in to correct this scenario by setting up more testing labs and enforcing quality standards.
By Deepshikha Shukla
Recently, ELCOMA organised a conference at Light India 2018 on Li-Fi and intelligent lighting designs, in order to create awareness about emerging technologies in the field. Intelligent lighting is the most versatile technology that can be used in LED lighting applications, along with the Internet of Things (IoT). It enables users to control the entire outdoor or indoor lighting system from anywhere in the world. Remote monitoring and control systems ensure high energy savings and have a proven ROI. Light India 2018 was focused on green lighting technologies and showcased a complete range of lighting solutions based on quality design, high performance, low maintenance and cost-effectiveness. It provided a great opportunity for exhibitors to share ideas and best practices that will contribute to the growth of India’s lighting sector.
One of the aims of ELCOMA is to make India a global leader in energy-efficient lighting. With this goal, it targets reducing the lighting sector’s share of national energy consumption from 18 per cent to 13 per cent by 2020. But to attain these figures, a sustainable global manufacturing hub for modern lighting products will need to be developed. LED testing infrastructure needs to be built to support the increasing demand for high quality products. To reduce dependence on imports and become an export hub, India needs to develop strong domestic manufacturing and assembling capabilities for LED lighting products and luminaires. It needs to set up LED testing labs, R&D centres, educational institutions and training centres to build up a skilled workforce. Only then can the country become a global leader in energy-efficient and smart lighting.
Parameters for LED testing
There are many parameters that need to be tested in order to accurately represent the specifications for LED lights. The LED performance testing parameters are divided into five broad categories.
Optical properties: Under this category, the optical colour, colour uniformity, chromaticity coordinates, CCT, colour gamut area, white balance, luminous flux, luminous efficiency, luminous power, luminous intensity distribution, luminance contrast, relative spectral power distribution, dominant wavelength, peak wavelength and half-peak wavelength are tested, Other parameters tested include colour rendering index, colour purity, red light ratio, colour display index, viewing angle, lighting glare, irradiance, illuminance, and spectral radiance of LED lights.
Electrical parameters: Here, we test the flicker characteristic of the display, the response time, crosstalk, power consumption, voltage, current, power factors, harmonics, LED accelerated aging, forward voltage, forward current, reverse voltage and reverse current. Also tested are parameters like the lifetime, electromagnetic compatibility, forward voltage/current, reverse voltage/current, standby power, LED drive power input, output starting performance and steady-state characteristics, power efficiency, fundamental frequency, and flash index.
Radiation safety test parameters: In this category, we test blue light weighted radiance, blue light hazard efficiency of luminous radiation, rapid transient pulse, retinal blue light hazard, retinal heat hazard, light radiation according to the corresponding standard, ultraviolet radiation ratio, apparent light source size, and colour tolerance.
LED thermal properties: Thermal calibration coefficient, junction temperature, the current-voltage characteristic curve ([email protected]—voltage (V); junction temperature with time curve, transient temperature rise and cooling curve, LED photometric and tube base temperature with time variation curve are tested under this category. LED chromaticity temperature and tube base temperature with time variation curve, LED junction voltage with time variation curve, LED junction voltage with photometric variation curve, and LED junction voltage with chromaticity change curve are the various other parameters tested in this category.
LED luminaires and module performance: Under this category, we test performance changes at high and low temperature, salt fog corrosion-resistance, rainproof performance, dustproof performance, electrostatic discharge, electrical fast transient immunity, surge immunity, time and frequency analysis of light output, apart from conducting tests to measure basic frequency, percentage flicker, flicker index (FI), modulation depth (MD), modulation percentage, zero voltage switching light source startup/rise time, total luminous flux, part light flux, spatial light intensity distribution curve, luminous intensity data, beam angle, utilisation coefficient, luminance limit curve, glare grade, effective average illuminance, and spatial colour uniformity.
Are manufacturers giving consumers the correct data about their LED products?
Achieving 200lm/W efficacy has been considered the next milestone for the LED lighting industry. Packaged LEDs surpassed that level several years back, but luminaires have struggled to reach the milestone at the system level due to optical losses and driver electronics losses.
A test case study shared by ELCOMA reveals that manufacturers are far behind in achieving the actual efficiency mentioned on the packaging, in real-time applications. Commercially-available luminaires sold with efficacy claims in the 200lm/W range delivered mixed results in US Department of Energy (DOE) testing at the Pacific Northwest National Laboratory (PNNL). With glare being a recurring issue, most products fall short of efficacy specifications. The US DOE released a short report covering the testing of rectilinear LED luminaires intended for high-output applications such as low- and high-bay lighting in industrial or commercial settings. Seven solid-state lighting (SSL) luminaires were tested, all of which the manufacturers had claimed delivered an efficacy in the range of 200lm/W. The intention of researchers was to measure photometric performance, conduct a subjective analysis for visual comfort under the lighting, and check for performance issues that could result from manufacturers pushing the lumen output to high levels.
The DOE SSL website featured the full report on the luminaires tested with the detailed characterisation of each. The researchers found that across the group, lumen output varied by 9.6 per cent and power consumed by 6.8 per cent relative to the manufacturers’ specifications. Lighting facts were based on the best-performing luminaire in a product family that included products with different correlated colour temperatures (CCTs) and other characteristics. The subjective testing, however, produced the worst results. Only two of the products received acceptable ratings for visual comfort and overall light quality—one included a diffused optic as opposed to exposing the emitters, and the second has an optical design to reduce glare by cutting off the beam at higher angles. The top-ranked luminaire was the lowest-performing product, delivering only 136lm/W. To be deployed in the desired application, the project tested 5000K luminaires but moving to 3000K-CCT products result in a 17 per cent efficacy drop. This means that the lighting industry is compromising on the light quality for high energy efficiency.
As per a survey by market research firm Nielsen, three-fourths of the LED bulbs sold in India (worth US$ 1 billion) were found to be non-compliant with the government’s consumer safety standards. The report was based on a study of 200 electrical retail outlets across major cities like Mumbai, Hyderabad, Ahmedabad and New Delhi in July 2018. It found the products to be spurious and risky, with the highest number of violations in the national capital. The report said spurious and non-branded LED products are a serious threat to market players and to the government’s key ‘Make in India’ programme that promotes local LED manufacturing. In August 2018, the Bureau of Indian Standards (BIS) had ordered LED makers to register their products with it for safety checks. Vikram Desai, president, ELCINA, says, “There has been a drastic fall in the tender price of LED bulbs, which is unsustainable and these rates are being quoted due to the use of subsidised supplies from China.”
The need to create standards for LED lighting
ELCOMA supports the setting up of standards for products, applications and testing, which are green and IEC compliant. Indian standards need to be mandatory for all products and applications. Regulations need to phase out inefficient lighting sources. IEC compliant product standards need to be created for better performance lighting products. A mandatory and strict energy conservation building code is required for big lighting users to promote the use of LEDs. Standardised labelling for lighting products is required to provide consumers with the right information to make decisions about efficacy, life, colour and wattage.
ELCOMA is trying to set up NABL (National Accreditation Board for Testing and Calibration Laboratories) approved LED testing facilities to support the growth of LED manufacturing. Manufacturers need to define lifetime testing specifications for all critical components used in lighting fixtures. The government, too, should abolish the import duty on testing equipment and ensure faster processing of NABL accreditation for testing labs.
SSL technology continues to evolve fast, and demands new methods of testing to evaluate the performance of LED bulbs. Evaluation results should always be understood in the context of the timeframe in which products were acquired, installed, operated and tested. Specifiers and purchasers should always seek current information from manufacturers while evaluating these products due to the rapid development cycle for SSL products. This information needs to be publicly available to track SSL technology performance improvements, over time; to identify technical challenges that impact performance, and to maximise energy efficiency while improving lighting quality.
The luminaire needs to deliver light while providing a range of lighting qualities such as colour quality, visual comfort, and minimal flicker. Various publicly accessible databases help specifiers to identify products with good characteristics and high efficacy. Those buying LED components should go to the manufacturer’s website to gather additional information, since the listing data may be based on the performance of a product very different from the one needed for a project. The published values often mask reductions in performance due to the use of different drivers, the LED colour, luminaire lumen output, and any efficiency loss due to improved optical control. So these should be used as a means to identify potential products for consideration, not for specifications.
The LED ‘Lighting Facts’ database can be potentially misinterpreted because the performance of a wide range of products in a family can be reported based on the tested performance of its best-performing product. The efficacy numbers may also be unreliable if they represent a particular model and set of characteristics across a family of products, with significant variation within that family in terms of lumen output, light distribution, CCTs, etc. In such cases, individual attributes like efficacy should be used only as a means for identifying potential products for consideration, followed by the collection of more detailed performance data for that product. So it is most important to evaluate a product’s attributes, in action, before making a selection, wherever possible.