How To Simulate 20 Years Of Thermal Stress In A Puncture Clamp Temperature Rise Cycle Test?

When a cable carries current, the conductor heats up due to the Joule effect; at night, when electricity consumption is low, the temperature drops. This constant thermal expansion and contraction, day and night, puts a continuous fatigue test on the contact interface of cable ipc connector. Temperature rise cycling tests are designed to reproduce this decades-long thermal stress impact in the laboratory.

Quantitative Standards for Thermal Cycling Tests

The industry-feasible testing method follows the GB/T2317.3 standard for thermal cycling tests of power fittings. electrical piercing connector is installed on an actual conductor and energized with a large current on the order of 100A/mm², after which the current is cut off to allow it to cool to ambient temperature. Such a "heating-cooling" process constitutes one cycle, which typically requires more than 200 cycles. The acceptance criteria include: the temperature rise of insulation connector throughout the entire cycle is always lower than the temperature rise of the connected wires; and the rate of change of contact resistance after the cycle ends is less than 5%.

Verification of the Stability of the Microscopic Contact Interface

The deeper value of temperature rise cycling tests lies in probing the evolution of the microscopic interface between the insulation piercing contact teeth and the conductor. Every temperature change causes material expansion and contraction. If the contact pressure is poorly designed or the blade material undergoes creep, the actual metal-to-metal contact area will gradually decrease. This reduction in contact area directly leads to increased contact resistance, which in turn causes a higher temperature rise, creating a vicious cycle. Through repeated thermal stress testing, we screened out product designs that could maintain a constant contact pressure during prolonged thermal cycling.