Technical Standards For Terminal Blocks: Ensuring Product Quality And Safety
As the core component of electrical connections, the technical standards of terminal blocks are directly related to the safety and stable operation of the power system. Currently, a complete standard system for the technical requirements of wiring terminals has been established both domestically and internationally, covering multiple dimensions such as materials, structure, performance, and testing methods.
Material standards are the foundation of the quality of wiring terminals. High quality terminal blocks are usually made of conductive metal materials such as copper alloys or tin plated copper, such as T2 copper, and undergo surface treatment (such as tin plating, silver plating) to enhance corrosion resistance. For example, UL certification standards explicitly require that wiring terminals have long-term stability in humid or chemically corrosive environments to prevent increased contact resistance or leakage risks caused by material degradation.
Structural standards ensure the reliability of electrical connections. The wiring terminal needs to have precise dimensional tolerances, such as screw hole diameter, terminal body length, etc., to adapt to different specifications of wires. At the same time, its design should support fast and secure wiring methods, such as snap on, plug-in or crimping, and be equipped with clear identification (such as model, specification, wiring direction) to avoid misoperation. For example, the GB/T 14048.7 standard stipulates that wiring terminals must pass 500 no-load insertion and extraction tests to ensure that their mechanical life meets the standard.
Performance standards are the core guarantee of safety. The wiring terminals must meet strict electrical performance requirements, including contact resistance, insulation resistance, temperature rise limit, etc. For example, the temperature rise limit for copper tin plated terminals is 65K, and for copper silver plated terminals it is 70K to prevent overheating and fire hazards. In addition, its flame retardant performance needs to reach V-0 level to ensure that it can delay the spread of fire in extreme situations.
The testing standard verifies the terminal performance by simulating actual working conditions. The testing items include impact, vibration, free fall, durability, etc., to ensure that the wiring terminals can still work stably in complex environments. For example, the IEC 60947-7 standard requires that wiring terminals undergo vibration testing in the frequency range of 10Hz-150Hz, and the insulation resistance deviation should not exceed 5%.