PCB Terminal Block Aging Causes and Testing Methods

The aging of PCB terminal connections can be caused by various factors. Firstly, environmental conditions and temperature play a significant role. High temperatures in the surrounding environment or from heat sources can cause the terminals to overheat, leading to insulation breakdown and even explosions or fires.

Secondly, chemical corrosion can also contribute to the aging of terminals. Prolonged exposure to chemical or electrolytic corrosion can degrade the protective insulation layer, reducing insulation effectiveness and accelerating aging.

Lastly, operating at overload for extended periods can cause terminals to overheat due to the heating effects of current flow. Excessive temperatures can speed up insulation aging, particularly in summer months.

To test for terminal aging, one method involves placing five terminals horizontally on a rail, connecting them with rated cross-section wires at least 300mm long, and measuring the voltage drop across each terminal. The test should be conducted in an aging chamber with temperature limits of 20°C to 75°C and a maximum working temperature of 120°C.

During the test, a rated current flows through the terminals for both heating and cooling cycles, with voltage drop measurements taken after every 24 cycles to assess aging. The entire testing process consists of 192 cycles.

Prior to testing, the voltage drop should not exceed 3.2mV. Regular monitoring of voltage drop can help identify aging terminals and prevent potential failures.

If you have any further questions or require assistance with terminal aging testing, please do not hesitate to contact us.