Terminal Block Manufacturing And Installation: Sharing Of Professional Skills And Experience

Terminal blocks are key components in electrical connections, and their manufacturing and installation quality directly affect the stability and safety of circuits. Here, we share practical tips from four aspects: material selection, manufacturing, installation, and inspection, to help improve engineering efficiency and reliability.

1. Material selection: Adapt to the scene and strictly control quality

Material matching: Select terminal materials based on current, voltage, and environment. For example, copper terminals have good conductivity and are suitable for high-current scenarios; tin plating or nickel plating can prevent oxidation; stainless steel or anti-corrosion coating terminals are required for humid environments.

Specification matching: The cross-sectional area of the wire must strictly correspond to the terminal hole diameter to avoid faulty connection or overheating. For example, a 4mm² wire should be connected to an appropriate Type 4 terminal, rather than being forcefully crimped onto a Type 2.5 terminal.

II. Manufacturing: Conduct precise operations to ensure crimping quality

Wire stripping length: Accurately strip the wire according to the terminal requirements (usually 1-2mm longer than the terminal depth) to avoid copper wire exposure or insulation layer indentation.

Crimp Tool: Use a dedicated wire crimping tool, select the appropriate jaw based on the terminal model, and ensure even pressure. Hydraulic crimping tools are suitable for large-sized terminals, while manual crimping tools are suitable for small-sized ones.

Crimp standard: After crimping, the wire should show no significant deformation, and the terminal should be free of cracks. The tensile test should reach over 80% of the wire's tensile strength.

III. Installation: Standardized layout, anti-loosening and moisture-proof

Secure fixation: The terminal strip needs to be fastened to the distribution box or guide rail with screws to avoid loosening due to vibration.

Clear identification: Use a label machine or marking pen to label terminal numbers and circuit names for ease of future maintenance.

Protective measures: Install a waterproof cover in humid environments, use heat-resistant terminals in high-temperature scenarios, and utilize anti-loose spring washers in areas with strong vibration.

IV. Inspection: multiple checks to eliminate hidden dangers

Visual inspection: Confirm that there are no issues such as poor crimping, burrs, or damaged insulation.

Resistance test: Use a multimeter to measure the resistance between terminals, which should be close to the resistance value of the wire itself.

Voltage withstand test: Conduct a power frequency voltage withstand test on the high-voltage circuit to ensure no breakdown or flashover occurs.

Lessons learned: Although terminal blocks may seem straightforward, it's the details that determine success or failure. It is recommended for beginners to practice crimping small-sized terminals to get a feel for the process. Before installation, verify the drawings, and after completion, conduct a simulated vibration test (by gently tapping the terminal strip) to check for tightness. Regularly recheck old terminals and promptly replace oxidized or deformed parts, which can significantly enhance the long-term stability of the circuit.