The selection of terminal blocks has always been a hot topic. For purchases that know the terminal model or have product pictures, it's okay to ask the terminal salesperson directly. However, for purchases that only have some product parameters or even no parameters, buying terminals is a headache. Below, Jointlean will share with you a guide for selecting wiring terminals.
01. Before selecting, it is important to understand what type of terminal you want?
According to the functional classification of terminals, there are ordinary terminals, safety terminals, test terminals, grounding terminals, double-layer terminals, double-layer conductive terminals, three-layer terminals, three-layer conductive terminals, one in two out terminals, one in three out terminals, double in two out terminals, knife switch terminals, overvoltage protection terminals, marking terminals, etc. Classified by current, there are ordinary terminals (low current terminals) and high current terminals (100A or above or 25MM wire or above). Classified by appearance, it can be divided into guide rail terminals, fixed terminals, circuit board terminals (PCB terminals), etc.
The selection of wiring terminals mainly includes wire diameter, current, wiring direction, application scenarios, wiring methods, and other wire diameters and currents. The wiring direction generally includes front wiring and side wiring, mainly for the convenience of technical personnel to operate and improve work efficiency in application scenarios. This is a very common problem. The application range of wiring terminals is relatively wide. For example, if you choose wiring terminals for soldering on a PCB board, it is impossible to choose the wiring method used on the guide rail. Generally, there are methods such as docking, hanging, and fixing. The basic composition of a universal terminal block consists of an insulating base, an insulating partition, and wire components, with the insulating base integrated into one.
02. What should be considered for selection?
The selection mainly considers the following points:
① Is the wire to be connected a hard wire or a soft wire?
② What is the cross-sectional area of the wire in square millimeters? (excluding wire skin)
③ What is the current and voltage that the terminal needs to withstand?
④ How many holes of connectors should be selected for use?
Each connector, regardless of the number of holes, is internally conductive. Therefore, we need to connect several wires together using connectors with several holes. For example, a 4-hole connector can connect up to 4 wires. If only 3 wires need to be connected, leaving only one hole is sufficient. Due to the internal conductivity of each connector, it is not possible to insert the live wire, neutral wire, and ground wire into the same connector, otherwise it will cause a short circuit. Therefore, in any case, one live wire must be used, one neutral wire must be used, and one ground wire must be used!
⑤ Can wires of different thicknesses be connected to the same connector?
The springs in each hole of the Zhuoneng electrical connector are independent, so wires with different cross-sectional areas can be safely and reliably used as long as they are within the connection range of the connector.
Jointlean Electrical Technology (Chuzhou) Co., Ltd. produces PCB terminal blocks, terminal blocks, track type terminal blocks, rectangular heavy-duty connectors, European connectors, etc. The company's main products have passed domestic and international certifications such as UL, TUV, CE, CQC, etc., meeting the ROHS directive. Some products have been tested by the Cape National Relay Protection and Automation Equipment Quality Supervision and Inspection Center. Do you want to learn more about terminal information? You can consult the online customer service of Jointlean. If you have time, welcome to visit and inspect the warehouse!