Rated voltage and rated current of the terminal cable

- 2023-03-13-

The extra voltage of the terminal connection wire is also known as the operating voltage. It mainly depends on the insulation material used and the distance between the touch pair. Certain components or devices may not perform their intended functions at below their extra voltage. The additional voltage of the terminal connection wire should in fact be understood as the maximum operating voltage recommended by the manufacturer. The guidelines state that the terminal connection wire will operate normally below the extra voltage. It tends to choose the extra voltage reasonably according to the voltage (electrical strength) target of the terminal connection wire, the application environment and the safety level requirements. In other words, the same voltage resistance 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 situation. 
Additional current of terminal connection wire is also called operating current. As with extra voltages, terminal connections generally work well below extra currents. In the planning process of terminal connection wire, the thermal planning of terminal connection wire is used to meet the additional current requirements. In the current flow period of the touch pair, the touch pair will heat up due to the existence of conductor resistance and touch resistance. When the heating exceeds a certain limit, the insulation of the terminal connection wire will be damaged and the softening of the surface coating will be formed by touch. Therefore, the additional current and, in fact, the temperature rise inside the terminal block must not exceed the planned rule value. In the selection of the problem to pay attention to is: for the multi-core terminal, the extra current is necessary to derate the use of. This should be paid more attention in the occasion of large current, such as φ3.5mm touch pair, the general rule of its extra current is 50A, but in 5 cores to derate 33% of the use, that is, the additional current per core only needs 38A, the more cores, the greater the derating rugged.



Planning process and making process of connecting wiring harness? 
(1) The electrical layout engineer shall provide the function, electrical load and relevant special requirements of the entire vehicle electrical system. Condition of wiring harness and electrical equipment, device orientation and docking mode. 
(2) According to the electrical function and requirements, make the electric schematic diagram and circuit diagram of the vehicle. 
(3) According to the electrical schematic diagram for each electrical subsystem and circuit energy distribution, including power grounding wire and address distribution. 

(4) According to the distribution of electrical components of each subsystem, confirm the wiring mode of connecting wiring harness, the electrical components connected by each connecting wiring harness and the direction on the car; Confirm the external maintenance mode and through hole maintenance of the wiring harness. Confirm fuse or circuit breaker according to electrical load; Color from the head; Check the type of terminals and sheathing that are connected to the wiring harness according to the adapter of the electrical equipment.