三菱 塑壳断路器;NF400-HEW 3P A
MITSUBISHI plastic shell circuit breaker; NF400-HEW 3P A
漏电保护
Leakage protection
漏电器有热磁式和电子式2种,相比而言电子式漏电器具有体积小、精度高、灵敏度高的优点,但其抗干扰能力较差。目前电子式漏电保护器占据主流,当漏电电流达到整定值时,执行电路接收零序电流互感器二次侧的感应电压信号,驱动转换触点输出漏电保护信号,使脱扣器动作切断电源。
The leakage electric apparatus has 2 kinds of thermal magnetic and electronic, compared with the small size, high precision, high sensitivity, but its anti-interference ability is poor. At present, the electronic leakage protector occupies the mainstream. When the leakage current reaches the setting value, the utive circuit receives the induction voltage signal on the two side of the zero sequence current transformer, and drives the transfer contact to output the leakage protection signal and makes the tripping device cut off the power supply.
一般终端开关的整定漏电脱扣电流为30mA、上一级支路开关的整定值为300mA。起火危险性大的电弧性短路难以被短路保护有效切断,而漏电器可以可靠的断开接地故障,防止人身触电和相地短路故障的发生。
The setting current of the general terminal switch is 30mA and the setting value of the upper branch switch is 300mA. The arc short circuit with high risk of fire is difficult to be cut off effectively by short circuit protection, and the leakage electric apparatus can disconnect the grounding fault reliably, so as to prevent the occurrence of personal electric shock and the fault of the phase to ground short circuit.