What Are The Reasons For The Terminal Fire

The wiring terminal of the power distribution cabinet is an important component inside the power distribution cabinet. Because of this, the wiring terminals in the power distribution cabinet are prone to heating and burning failures. Let's talk about the analysis of the reasons for the burning failure of the wiring terminals of the power distribution cabinet.

Cage spring terminal blocks are convenient for wiring and compact in structure. Due to their wide range of applications, but due to the compact connection between the terminals, it is not easy to find on the outside when the internal burnt is The main reasons for the damage are as follows:

1. Heating of current-carrying conductor: Because the wiring of the reed cage terminal of the main line in the power conversion cabinet is 16m, the reed elasticity is relatively large, and the opening angle of the reed is not enough when the wiring is connected to people. The conductor (multi-stranded wire) of the wiring part is not pressed into the reed, and the actual conductive area is reduced, and abnormal temperature rise occurs when the current passes. Experiments have proved that the mechanical strength of metal conductors is reduced due to annealing at high temperatures. When copper exceeds Q0, its mechanical strength drops sharply, which reduces the pressure at the touch point between the reed and the conductor, and increases the touch resistance, resulting in heat generation. more serious. At the same time, due to heat, the conductive body is strongly oxidized on the touch surface, resulting in copper oxide whose resistance is much greater than that of the conductive body itself, which greatly increases the touch resistance, resulting in a sharp increase in heat at the touch point, forming a vicious circle, and loosening and deforming the touch part of the conductive body. , And even produce melting phenomenon.

2. In terms of the touch resistance of the cage terminal: because the conductor and the reed (bayonet) of the wiring are in line touch instead of face touch, when the conductor enters the reed (bayonet) too long or too short, the spring The pressing force of the sheet (bayonet) cannot make the wiring conductor and the conductor inside the cage terminal form an outstanding touch. The touch resistance is added, and when the current is passed for a long time, it is easy to cause abnormal heating and burning of the cage terminal.

3. Insulation layer heating of cage resistor card housing: When the conductor of the wiring enters the reed (bayonet), the reed (bayonet) presses part of the insulation layer of the wiring, because the insulation layer has a certain thickness, The pressing force of the reed (bayonet) to crimp the wiring conductor is not enough, and the touch resistance is added. When the current passes for a long time, it is easy to cause abnormal heating and burning of the cage terminal.

In addition to the above reasons, there are some other factors that can also cause burning failures in the wiring terminals of the distribution cabinet, which will not be explained in detail here. It is the most effective way to prevent the occurrence of burning failures in the wiring terminals of the distribution cabinet. The way is to check beforehand.