What Hidden Changes Will Occur In The Copper Terminal Block After The Insulation Component Heats Up?

In the daily operation of electrical connections, people often focus on the load on the metal components, easily overlooking the insulating base immediately adjacent to them. When a large amount of heat spreads from the conductor to the insulator, the originally stable copper terminal block connection begins to be tested. This heat transfer is not an isolated physical phenomenon; it directly affects the lifespan of the entire electrical node.

Material Aging Leading to Loosening of Fastening Force

After absorbing the dissipated heat, the molecular structure of the insulator undergoes slight physical deformation due to the high temperature. This change may seem insignificant, but for copper distribution block devices that rely on screws or springs for clamping, the softening or expansion of the base will alter the originally set clamping pressure.

• Deformation Displacement: The coefficient of thermal expansion of plastic housings differs from that of metals; alternating hot and cold temperatures can cause gaps to appear at the contact surface.

• Performance Degradation: Insulating materials exposed to heat for extended periods become brittle, losing their rigidity in supporting the metal components.

• Creep Phenomenon: Under high-temperature environments, the insulating material undergoes permanent deformation under pressure, causing the connection to become less tight.

Oxide buildup causes a surge in resistance.

Heat is transferred back or accumulated through the insulation, keeping the copper terminal strip in a miniature "oven" environment. This environment accelerates the chemical reaction on the copper surface. The originally shiny contact surfaces quickly become covered with a layer of oxide film, invisible to the naked eye.

This film acts like an invisible wall. When current passes through this film, the resistance is much higher than normal. Higher resistance leads to greater heat generation, which is then conducted back to the insulation. This vicious cycle is the trigger for many burn-out accidents.

A substantial decline in electrical insulation rating.

If heat continues to accumulate, the insulation does more than just discoloration. Many engineering reports show that when insulation performance deteriorates due to high temperatures, the creepage distance and clearance between copper terminal blocks effectively lose their protective function.

Insulation materials may release volatiles at high temperatures. These substances adhere to the copper busbar surface and easily form conductive paths when exposed to moisture. In this case, even if the equipment doesn't appear burnt, the risk of internal leakage has increased exponentially.