UL is the abbreviation of Underwriter Laboratories Inc., which is the most authoritative in the United States and the largest private institution engaged in safety testing and identification in the world. It is an independent, not-for-profit, professional organization that conducts experiments for public safety. It uses scientific testing methods to study and determine whether various materials, devices, products, equipment, and buildings are harmful to life and property and the degree of harm. It determines, compiles, and distributes appropriate standards and materials that help reduce and prevent loss of life and property, and conducts fact-finding operations. UL certification is a non-compulsory certification in the United States, mainly for the testing and certification of product safety performance, and its certification scope does not include the EMC (Electromagnetic Compatibility) characteristics of the product. It is mainly engaged in product safety certification and business safety certification. Its ultimate goal is to obtain products with a certain level of safety for the market and contribute to the guarantee of personal health and property safety. In terms of product safety certification as an effective means of eliminating technical barriers to international trade, UL also plays an active role in promoting the development of international trade.
Founded in 1894, UL is a non-profit product safety testing and certification organization. There are more than 50 laboratories around the world, with about 6,000 employees. Every year, thousands of products are certified by UL and use the UL mark. Currently, UL has nearly 800 sets of standards, 75% of which are adopted by the American National Standard Institute(ANSI).
In fact, the establishment of product safety standards is inevitable. If there is no widely recognized product safety standard, the significance of product performance testing will be limited. On behalf of industry organizations, manufacturers and governments, UL has established a flexible and operational safety standard, which is widely implemented domestically and internationally.
The second and most obvious function of UL is the product and component testing. Its testing scope has exceeded 12,000 products, which are tested in 4 independent laboratories covering an area of 1 million square feet. UL can evaluate the electrical, fire protection and safety performance of various materials, equipment, buildings and systems. In addition to testing and certifying the overall system, UL can also test its components. All tested and recognized components are listed in the UL Recognized Components Index.
When one or more products of a manufacturer are listed in the UL list, UL inspectors will visit the production factory to investigate without prior notice.
During the investigation process, UL inspectors will record the manufacturer's production control, record customs declaration, on-site product testing, parts and machine testing, etc. The purpose of this unannounced inspection is to ensure that UL-marked products are produced in full compliance with UL's requirements. Such unannounced inspections are conducted at least four times a year.
PBM currently has UL certificates for the PB3N175B12H and PB3N250B1E-TY0. We use the UL507 test standard and conduct the following tests:
1, Leakage current test;
2, Grounding circuit continuity test;
3, Starting current test;
4, Input test;
5, Temperature rise test;
6, Withstanding voltage test;
7, Waterproof test;
8, Stalled rotor test;
9, Tidal state test;
10, Power cord torque test;
11, Wind blade test without protective cover;
12, Power cord Thrust test;
13, Fan swing test;
14, Protective shell ball impact test ;
15, Protective shell static pressure test;
16, Portable fan blade test;
17, Drop test;
18, Handle safety test;
19, Stability test;
After passing all the tests, they gave us the UL certificate.
Test item 1: locked rotor temperature test
Test method: The motor was mounted on a thermally insulated surface and oriented based on the marked instructions.
The rotor was locked and the frame grounded by a 3 A non-time delay cartridge fuse.
For the motor with a non-conductive enclosure, wrap the non-conductive enclosures in metal foil and to connect all accessible (or dead) metal parts together to the metal foil and then connect through a 3 A-ampere non-time delay cartridge fuse to the ground.
The sample was energized at the indicated test voltage for ten cycles of operation, with the control being reset as quickly as possible each time it opened the motor circuit.
Thermocouples were placed on the motor windings and temperatures were monitored with a suitable instrument for the entire test.
Test results: the speed setting is 3200RPM, the maximum ambient temperature is 24.8°C, the test temperature rise is 33.6, and the test is passed.
Test item 2: dielectric voltage-withstand, test after locked rotor, temperature test, dielectric strength test
Test method: Immediately following the locked rotor temperature test, the machine was subjected to the application of an alternating-current potential at a frequency within the range of [40 - 70hertz for UL Only][50 - 60 hertz] or a direct-current potential:
Test result: passed
Test item 3:locked rotor endurance test(manually reset protection)
testing method: If the maximum temperature on the motor winding measured during the locked-rotor test exceeded the normal temperature limits for the insulation system employed or the maximum current measured during the locked-rotor temperature test exceeded the normal operating current, the manually reset mojector protected to an additiona.1 50 cycles of operation immediately following the locked-rotor temperattre and dielectric voltage-withstand tests.
During the test, the motor was energized at the voltage indicated below with rotor locked and the frame grounded by a 3 A non-time delay cartridge fuse.
Immediately after the conclusion of the endurance test, and while still in a heated state, the sample was subjected to a Dielectric test at twice the marked rated voltage between dead-metal parts and the windings for 1 minute.
Test result: passed
PBM is a China mainland EC(Electronically Commutated) brushless motor manufacturing and technology consulting company offering an extensive range of EC motors, fans and intelligent ventilation solutions for air-moving precisely and constantly with maintenance-free throughout the life cycle of products in the last decades. If you are in need of UL-certified EC fans, please kindly contact us today!