In fact, the leakage circuit breaker adds an accessory to the ordinary circuit breaker. Currently on the market, most of the accessories are already installed at the factory. Users can also purchase accessories for installation.
This leakage protector accessory provides a function-leakage protection. When a leakage accident occurs in the circuit, the device can automatically trip and power off.
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 temporary electricity at construction sites or in socket circuits in 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.
Leakage circuit breakers and air switch action detection methods are 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 and neutral currents in the protected circuit (including the middle Three-phase unbalanced current and harmonic current in the neutral line). 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. Circuit breakers are used to prevent overloads, short circuits, and cut off power when maintaining circuits.
The leakage circuit breaker emphasizes that if an excessive current occurs within a specified time, the mechanical structure is buckled.
From the point of view of use, circuit breakers are used to protect the safety of equipment and lines; leakage protectors emphasize the protection of people and prevent fires.