To solve the problem when using the terminal, pay attention to the following phenomena:
The first phenomenon: the wiring terminal is not in good contact. The metal conductor inside the wiring Connecting Terminals is the core part of the terminal. It transfers the voltage, current or signal from the external wire or cable to the contact corresponding to its matching connector. Therefore, the contact must have excellent structure, reliable contact holding force and good electrical conductivity.
The second phenomenon: poor insulation of the Terminals: the function of the insulator of the Insulated Terminals is to keep the contacts in the correct position, and to insulate each other between the contacts and the contacts and between the contacts and the shell. Therefore, the insulating parts must have excellent electrical properties, mechanical properties and process forming properties. Especially with the widespread use of high-density and miniaturized terminal blocks, the effective wall thickness of insulators is getting thinner and thinner.

Third phenomenon: Poorly fixed terminal block insulators not only insulate, but also usually provide accurate neutralization protection for extended contacts, and also have the function of installation, positioning, locking and fixing to the equipment. Bad fixation, light influence contact reliability resulting in instant power failure, serious is product disintegration. https://www.bossgoo.com/product-detail/electrical-copper-pre-insulated-ring-terminal-61372108.html