A, LED status of the North American standard
LED energy saving lamps, as a new product, now the current North American product safety standards are not specific to the technical requirements of such products, LED product testing as an industry issue. American UL laboratory for the current industry conditions, is organizing the preparation of safety certification standards for energy-saving LED lights UL8750, the standard is still a draft, not being formally adopted as the certification standards. Thus, LED energy saving lamps certification test questions, not being completely resolved.
The basic principle of energy-saving LED lights by switching power supply module AC power into DC to supply power to the light-emitting diode. According to the basic principles of energy-saving LED lights and structural features, MET Laboratories, the U.S. proposed a transitional stage of the testing program: the traditional energy-saving lamps American certification standards UL1993 (corresponding to the Canadian Standards CAN/CSA-C22.2No.0, CAN /CSA-C22.2No.74), and standard power modules, or UL1310 UL1012 (corresponding to the Canadian Standards CAN/CSA-C22.2No.107) for energy-saving LED lights for testing and certification.
Second, the detection techniques
Following on the basis of UL1993, UL1310 and UL1012 standards for LED lamps in certification testing of the key issues, do some elaboration.
1. Material
LED lamps can be made into various shapes, to energy-saving fluorescent tube LED lights, for example, with its shape, like an ordinary fluorescent tube, fluorescent tube transparent polymer shell by the power module and the light-emitting diode packages inside. Transparent polymer shell to play in the fire and electric shock the product features. According to standards, energy-saving lamp shell material is required to achieve V-1 level above, the transparent polymer shell to be used for more than V-1 grade material. It should be noted is that the product enclosure to achieve the required level of V-1, its thickness must be greater than or equal to V-1 grade of raw materials to the required thickness, fire rating and material thickness requirements in the UL yellow card check to.
Found in the actual testing, the manufacturer in order to ensure the brightness of LED lights, often very thin transparent polymer shell, which requires test engineers to pay attention to ensure that materials meet the required fire rating thickness. Since different materials have the same fire rating requirements of different thickness, some raw materials in smaller thickness to meet the higher fire rating requirements, recommended that manufacturers can choose the right materials to do the product casing.
2. Drop test
According to product standards, to simulate the actual use of the product may occur during the fall drop test case for product fell from a height of 0.91 meters hardwood panel products as well as exposing the shell does not rupture the internal hazardous live parts. Manufacturers to choose material from the product case, we must consider the strength requirements
3. Dielectric strength
Surrounded by a transparent cover in the power module inside the transparent shell material must meet the electric strength requirements. According to standards, based on the conditions of the North American voltage of 120 volts, the internal high-voltage live parts and case (covered with foil test), to be able to withstand 1240 volts of AC electric strength test. Under normal circumstances, the product shell thickness of about 0.8 mm, which can meet the electric strength test requirements.
4. Power module
LED power supply module is an important part of energy-saving lamps, power supply module using switching power supply technology. Press the power module types, consider using a different standard for testing and certification. If the power module is classII power, which can be used to test UL1310 certification. classII power is the use of isolation transformer, the output voltage falls below 60 volts DC, current is less than 150/Vmax amp power supply.
While the non-classII power, is used to test UL1012 certification. The technical requirements of these two standards are very similar, can cross-reference. Most LED lights internal power module is associated with non-isolated power supply, power supply output voltage is greater than 60 volts DC, so do not apply UL1310 standard, applicable to UL1012
5. Insulation requirements
Because LED lamps inside the limited space, the structural design, pay attention to hazardous live parts and accessible metal parts between the insulation requirements. Insulation can be a distance and creepage distance, it can be insulating film. According to standards, hazardous live parts and accessible metal parts to achieve the distance between 3.2 mm creepage distance is 6.4 mm. If the distance is not enough, you can add insulation film as an additional insulation, insulation thickness is greater than 0.71 mm, if the thickness is less than 0.71 mm, the product will have to be bearing 5000V high voltage tests.
6. Temperature rise test
Temperature rise test is a necessary product safety testing a project, the standard of the different components have a certain temperature limit. In the product design phase, manufacturers should attach great importance to the heat dissipation problem, especially for certain components (such as insulating films, etc.) should pay particular attention.
Components if long-term work in hot conditions, easily damaged, resulting in fire or electric shock. Lamp power supply module is enclosed within a small space, heat dissipation is restricted. Therefore, the manufacturer of component selection, pay attention to choose the right component specifications, to ensure a certain margin component in the work, thus avoiding long-term component in the close to full working conditions arising from overheating.
7. Structure
LED energy saving lamp power supply module is installed inside the shell, space is limited, and some manufacturers in order to save space, the surface of the pin-type components soldered on the PCB, this is unacceptable. The surface of the pin welding-type component is likely to fall off because Weld and other reasons, dangerous. Therefore, these components should be taken as welding jack. If forced to take the surface of welding, will have to glue these pieces plus a fixed component, etc. used to provide additional protection.
8. Fault test
Product failure testing is critical to product certification testing in a test project. This test project is on the line short or open some of the components, to simulate the actual process may occur in the failure to assess products in a single fault conditions of security. In order to meet the safety requirements of product design, to consider the input of the product plus the appropriate fuses to prevent the output short circuit or internal component failure occurred when the current causing a fire hazard.
Third, the factory inspection
North American product certification to inspect factories, factory inspection, including the first factory inspection and follow-up examination. If the plant is the first application is the North American product certification, will have to be the first factory inspection. The first factory inspection focused on plant quality assurance system requires that the factory has perfect quality assurance system to ensure product quality and ensure effective supervision. If the factory has been established in accordance with ISO9000 quality management system standard, and passed ISO9000 certification, basically in line with the first factory inspection management system requirements.
If the plant does not pass the ISO9000 certification, will have to purchase raw materials, incoming inspection, inventory management, product design, engineering changes, production line testing, instrument calibration, and follow up complaints have clear program files, and effective implementation. Follow-up inspection is the main structure for the product line product inspection and testing, to ensure the production line of product structure and the certification approved sample, and through the associated production line testing. Manufacturer of the product through testing and certification, the certification must be in strict accordance with the list of sample structure and components for production, any changes that may be involved in product safety certification organization must inform the assessment. If necessary, you may want to re-test and report changes. Product test report of the production line test is a clear requirement, manufacturers must follow the requirements of the relevant tests, such as high-pressure testing, ground continuity testing |
