Ren Yi official website updated on July 9

 

Regarding the question of whether the leakage switch can replace the air switch, the air switch is different from the leakage protector. The correct name of the air switch is called the air circuit breaker, and the correct name of the leakage switch is the residual current protection device. The leakage switch cannot replace the air switch.

 

Can the leakage switch replace the air switch

 

1. Air switch, its correct name is called air circuit breaker.

 

Air circuit breakers are generally low voltage, that is, the rated working voltage is 1Kv.

 

The air circuit breaker is a switching device with multiple protection functions that can cut off and connect the circuit under the conditions of rated voltage and rated operating current.

 

Its protection function type and protection mode are selected by users according to their needs. Such as short circuit protection, over current protection, shunt control, under voltage protection, etc. The first two protections are the basic configuration of air circuit breakers, and the latter two are optional functions.

 

The air circuit breaker can also cut off the electrical circuit in a fault state (load short circuit, load overcurrent, 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 a special protection function (leakage protection).

 

What it detects is the residual current, that is, the algebraic sum of the instantaneous values ​​of the phase and neutral currents in the protected circuit (including the three-phase unbalanced current and harmonic current in the neutral). For this reason, the setting value of RCD, namely its rated operating current IΔn, only needs to avoid the normal leakage current value, which is measured in mA, so RCD can cut off the ground fault of the protection circuit very sensitively, and can also be used as Back-up protection against direct contact and electric shock.

 

Leakage protector is a kind of protective electrical appliance that uses to detect the phase-to-ground leakage or electric shock current that occurs in the protected power grid, and as a protection device that sends out an action trip signal and completes the action trip task.

 

In a low-voltage power grid equipped with a leakage protector, under normal conditions, the phase-to-earth leakage current of the grid (unbalanced leakage current for a three-phase power grid) is small and cannot reach the operating current value of the leakage protector. , The leakage protector does not operate.

 

When a fault such as leakage or personal electric shock occurs in the protected power grid, when the current through the leakage protector detection element reaches its leakage or electric shock action current value, the leakage protector will generate an action trip instruction to make the master controlled The circuit switch action trips and cuts off the power supply, thereby completing the task of leakage or electric shock protection. In addition to the basic functions of the air circuit breaker, it can also quickly disconnect the switch when the load circuit leaks (its leakage current reaches the set value), so as to avoid injury to personnel and disadvantages to electrical equipment when the load circuit leaks. influences.

 

3. The leakage switch cannot replace the air switch.

 

Although the leakage switch has one more protection function than the air switch, it will often trip due to the possibility of leakage during operation, which will cause frequent power outages of the load and affect the continuous and normal operation of electrical equipment. Therefore, it is generally only used in the temporary electricity supply on the construction site or in the socket circuit of industrial and civil buildings.

 

The leakage switch can also be said to be a kind of air switch, with similar mechanical actions and arc extinguishing methods. But because the leakage switch protects the human body, the general action value is milliampere level.

 

In addition, the action detection method is different: the leakage switch uses the residual current protection device, which detects the residual current, that is, the algebraic sum of the instantaneous values ​​of the phase and neutral currents in the protected circuit (including the neutral Three-phase unbalanced current and harmonic current). For this reason, the rated operating current only needs to avoid the normal leakage current value (milliamp level), so it can cut off the ground fault very sensitively and prevent direct contact electric shock. The air switch is a pure overcurrent trip (ampere class).

 

Sichuan Renyi Electric Co., Ltd. is registered under the name of Ren Yi, a senior technician for substation maintenance, and uses scientific research, knowledge innovation, publicity, promotion, and teaching that the temperature of electrical contacts (connectors) is lower than the temperature of its conductors (wires). The theory and technology of "thermal electrical contacts" produces and sells registered trademark electrical equipment that does not heat electrical contacts (joints), as a whole with patented products.