Rated voltage and rated current of wire harness

The rated voltage of the Wire Harness is also called the operating voltage. It mainly depends on the insulating material used and the distance between the contact pairs. Certain components or equipment may not be able to perform their intended functions when the voltage is lower than their rated voltage. The rated voltage of the wiring harness should actually be understood as the highest operating voltage recommended by the manufacturer. In principle, PCB cables can operate normally below the rated voltage. The editor tends to reasonably select the additional voltage based on the withstand voltage (electrical strength) index of the wire harness, the application environment, and the safety level requirements. In other words, the same withstand voltage target can be applied to different maximum operating voltages according to different application environments and safety requirements. This is also more in line with the objective application conditions.

The rated current of the wire harness is also called the operating current. Like the rated voltage, it can generally operate normally when the rated current is lower than the rated current. During the planning process, the additional current requirements are met through thermal planning of the wire harness. Since current flows through the touch pair, the touch pair will generate heat due to the presence of conductor resistance and touch resistance. When its heat exceeds a certain limit, it will damage the insulation of the connecting wire and cause contact softening of the surface coating, causing failure. Therefore, to limit the additional current, it is actually necessary to limit the internal temperature rise not to exceed the planned specified value. The issue to note when selecting is: for multi-core terminal blocks, the rated current must be derated. This should be paid more attention to in large current situations. For example, for a φ3.5mm touch pair, the rated current is generally 50A, but when using 5 cores, it must be derated by 33%. That is, the rated current of each core is only 38A. The higher the number, the greater the derating range.