Factors Affecting The Selection Of Terminal Blocks
Terminal blocks are the core components of electrical connections, and their selection requires comprehensive consideration of multiple factors to ensure the safe, reliable, and efficient operation of the electrical system. The following is a summary of the main influencing factors:
1. Electrical parameter matching
Rated voltage and current
The selection should be based on the actual load of the circuit, for example, industrial equipment often requires specifications above 1000V/50A, while consumer electronics may only require 250V/10A.
Insulation performance
For scenarios with high environmental humidity or dust (such as outdoor distribution boxes), insulation materials with a protection level of IP65 or higher should be selected.
Temperature rise characteristics
In high current scenarios, the terminal temperature rise should be below 40K (such as copper terminals having better current carrying capacity than aluminum).
2. Mechanical structure adaptation
Wire diameter range
It is necessary to cover the cross-sectional area of the wire (such as 0.5-16mm ²) to avoid loose crimping caused by thick wires or high contact resistance caused by thin wires.
Installation method
Rail type (DIN rail) is suitable for cabinet installation, screw type is suitable for fixing panels, and spring type is suitable for quick insertion and removal scenarios.
space limitation
High density distribution boxes require the selection of miniaturized terminals (such as micro terminals with a spacing of only 5mm).
3. Environmental and reliability requirements
corrosion resistance
Nickel/tin plated terminals should be selected for coastal or chemical environments to avoid poor contact caused by oxidation.
Anti vibration performance
Car mounted equipment should choose terminals with anti loosening design (such as locking screws+double nut structure).
Lifetime demand
Frequent plugging and unplugging scenarios (such as testing equipment) require selecting industrial grade terminals with a plugging and unplugging frequency of ≥ 500 times.
4. Cost and Maintenance
Single point cost
When purchasing in bulk, the unit price of ceramic insulated terminals may be 30% higher than that of plastic terminals, but their long-term reliability is better.
Maintain convenience
Modular terminal blocks (such as detachable ones) can reduce the difficulty of troubleshooting and minimize downtime.
Summary: The selection of terminal blocks should be based on electrical parameters, and balanced with mechanical structure, environmental conditions, and cost objectives. For example, in industrial automation scenarios, it is recommended to use track type terminals with protective covers, while in consumer electronics, miniaturization and low-cost solutions are prioritized.
