According to UL 1059, every terminal block must carry a verified maximum operating temperature, typically ranging from 85°C to 150°C depending on the housing material and conductor size. In the daily maintenance of power distribution systems, the biggest concern is the unexplained overheating of the wiring terminals. In fact, the fact that the earth distribution block does not overheat during long-term operation at rated current directly determines the service life of the entire. When terminations are inside equipment such as panelboards, motor control centers, switchboards, enclosed circuit breakers, safety switches, etc. Manufacturers commonly use 90°C-rated lugs. In electrical installations, termination temperature ratings plays a key role in ensuring safe, efficient, and code-compliant connections. Why does it matter? Because. The temperature rise of lugs is within acceptable levels per UL508, Section 43, Temperature tests. 1, terminals marked 60/75C for supply wires can have a temperature rise of 50°C above 40°C ambient temperature, while terminals marked 75C for supply wires can have a temperature. 60, 75 and 90 represent the common temperature termination rating of device connection points to wiring beyond the device. What does the number represent as in regards to the device? Does a 60 deg C device have the possibility to have its connection point heat to 60 C, therefore the conductor on. Loose connections or worn out contact surfaces are the root causes of electrical system conduction troubles. This causes thermal runaway, which damages the insulating material at high.