English definitions UL: UL Underwriter Laboratories Inc. is shorthand. UL310 is fast connections for terminal authentication. UL Certification Terminals: Underwriter Laboratories Inc TerminalsUL development history: 1890 1894: creation of UL UL founder of Williams Merrill (William Henry Merrill) Mr. founded the "underwriting Electrical Engineering Bureau" (Underwriters Electrical Bureau) Terminals row, that is, "the US National Fire Department of Electrical Engineering Bureau" (Electrical Bureau of the National Board of Fire Underwriters) predecessor. March 24, 1894, the project office conducted its first test terminals models, test subjects as "Mr. Shields" non-flammable insulation material. Bulkhead with screw cable technology, insulation material is PA66 (flammability rating: UL94, V-0), connector using high-quality high-conductive metal material. H-type wall-type terminals can be mounted side by side on the thickness of 1mm to 10mm and other panel, the panel thickness adjustment automatically compensates for the distance, the composition of any number of poles of the terminal block, and can be used to increase the air gap separating plate and creepage distance. No tools can be wall-type terminals securely mounted in the rectangular holes for the panel, extremely easy to install. 5.2.1 The individual elements of the two terminals with two consecutive numbers to distinguish the odd number should be less than even numbers, such as a single intermediate element and 2.5.2.2 use numbers to distinguish each terminal, preferably by increasing the number of natural sequence numbers. For example: 3,4,5, etc. Each terminal is greater than the selected intermediate digital numbers on both sides of the terminals, and the terminals should be close to the start flag at the smaller numbers, e.g., as an intermediate element on both sides of the terminal 1 and the terminal 2 with each terminal 3, 4, 5, and other digital signs. Both sides terminals and two intermediate terminals 5.2.3 If several similar elements are combined into a group, the terminal can be connected to various components of the following methods to mark: a. 5.2.1 Digital preceded by letters and by regulation 5.2.2 to distinguish between each of the terminals on both sides of the terminal and intermediate, for example: With each phase terminal U, V, W flag three-phase AC system equipment; wiring terminal blocks, electronic products factory Song Chong-wook, terminals supplied by Asahi Dongguan Shijie Chong-electronic products factory. Dongguan Shijie Xu Chong-electronic products plant (chuangxs.1688.com) (www.chuangxs.1688.com) Dongguan, Guangdong, connectors leaders, over the years, the company is implementing the scientific management, innovation and development, honesty and trustworthiness policy, and satisfy customer needs. Song Chong-wook in electronic products factory leadership with the staff warmly welcome all inquiries negotiations to create electronic products factory Song Chong-wook better future.