The difference between leakage circuit breaker and air circuit breaker

1], the air circuit breaker is generally low voltage, that is, the rated working voltage is 1Kv. The air circuit breaker is a switching device that has various protection functions and can cut and close the circuit under rated voltage and rated operating current conditions. The type of protection function and the way it is protected are selected by the user as needed. Such as short circuit protection, over current protection, shunt control, under voltage protection. The first two protections are the basic configuration of the air circuit breaker, and the latter two are optional functions. Therefore, the air circuit breaker can also cut off the electrical circuit in the fault state (load short circuit, load over current, low voltage, etc.).

      2], the correct name of the leakage switch is the residual current protection device (hereinafter referred to as RCD), which is an air circuit breaker with special protection function (leakage protection). It detects the residual current, which is the algebraic sum of the instantaneous values ​​of the phase and neutral currents in the protected loop (including the three-phase unbalanced current and harmonic current in the neutral). To this end, the setting value of the RCD, that is, its current operating current IΔn, simply avoids the normal leakage current value, which is measured in mA, so the RCD can very sensitively cut off the ground fault of the protection circuit and can also be used as Protection against direct contact with electric shock.

      The leakage protector is a protection device that detects the leakage current or electric shock current of the phase line occurring in the protected power grid, and acts as a trip signal to complete the action and complete the action trip task. In the low-voltage power grid with the leakage protector, under normal circumstances, the leakage current of the grid phase-to-ground (unbalanced leakage current for the three-phase grid) is small, and the operating current value of the leakage protector is not reached. The leakage protector does not work. When a fault such as electric leakage or personal electric shock occurs in the protected power grid, when the current of the component is reached by the leakage protector to reach the leakage or electric shock current value, the leakage protector will give an action trip command, so that the main control The circuit switch action trips and cuts off the power supply, thus completing the task of leakage or electric shock protection. In addition to the basic functions of the air circuit breaker, it can quickly break the switch when there is leakage in the load circuit (its leakage current reaches the set value) to avoid injury to personnel and adverse effects on electrical equipment when there is leakage in the load circuit. influences.

      3], the leakage switch can not replace the air switch. Although the leakage switch has a more protection function than the air switch, the possibility of leakage due to the possibility of leakage during operation often occurs, resulting in frequent power failures and affecting the continuous and normal operation of the electrical equipment. Therefore, it is generally only used in the temporary circuit of the construction site or the socket circuit of industrial and civil buildings.

The leakage switch can also be said to be a kind of air switch, and the mechanical action and arc extinguishing method are similar. However, since the leakage switch protects mainly the person, the general action value is milliampere.

      In addition, the action detection method is different: the leakage switch uses a residual current protection device, which detects the residual current, that is, the algebraic sum of the instantaneous values ​​of the phase line and the neutral current in the protected circuit (including the neutral line) Three-phase unbalanced current and harmonic current). For this reason, the current flow current can only avoid the normal leakage current value (milliampere level), so it can cut off the ground fault very sensitively and prevent direct contact with the electric shock. The air switch is a pure overcurrent trip (safety level). 9. The difference between the zero line and the ground line of the alternating current 220V. The difference between the zero line and the ground line of the alternating current 220V.