Chint leakage protection switch NL18-20/20A

The Chint leakage protection switch NL18-20/20A is an electrical protection device suitable for households and similar places. The following is a detailed introduction to it:  

 Specifications and Parameters  

- **Rated Current**: 20A. This means the leakage protection switch can stably carry a current load of 20A for a long time. When the current in the circuit exceeds this value, the switch may trip automatically to protect the circuit safety.  

- **Rated Voltage**: It is applicable to single-phase circuits with alternating current 50Hz and a rated working voltage of 230V, effectively ensuring normal operation and leakage protection functions in this voltage environment.  

- **Rated Current of Trip Device**: Usually 600A, which refers to the rated current that the trip device can withstand. When faults such as overload or short circuit occur in the circuit and the current reaches the rated current of the trip device, the trip device will act to make the switch trip and cut off the circuit.  

- **Rated Ultimate Short-Circuit Breaking Capacity (Icu)**: 50KA. It indicates that the switch can reliably break the maximum short-circuit current of 50KA under specified test conditions, reflecting the switch's breaking capacity and protection performance during short-circuit faults.  

- **Action Characteristics**: When the leakage current in the circuit reaches a certain value (such as 30mA), the leakage protection switch will trip automatically and cut off the power within an extremely short time (usually no more than 0.1 seconds) to prevent accidents such as electric shock and electrical fires.  

Product Features  

- **Residual Current Protection Function**: It can monitor the residual current in the circuit in real time. When leakage occurs, it quickly cuts off the power to protect personal safety and prevent electric shock accidents.  

- **Small Volume and High Breaking Capacity**: With a small volume, it is convenient to install in distribution boxes or electrical equipment. Meanwhile, it has a high short-circuit breaking capacity, which can quickly cut off the short-circuit current and protect circuit equipment from damage caused by short-circuit current.  

- **Reliable Action and Good Vibration Resistance**: Made of high-quality materials and advanced manufacturing processes, it ensures the switch can act reliably under normal use and harsh environmental conditions. It has good vibration and impact resistance, guaranteeing the stability and reliability of the leakage protection switch.  

- **CCC Certification**: It has passed the China Compulsory Product Certification (CCC Certification), indicating that the product meets relevant national standards and safety requirements, with high quality and safety.  

 Working Principle  

- Under normal conditions, the current in the circuit flows in from the live wire (L), passes through the load, and flows out from the neutral wire (N). At this time, the current in the live wire and neutral wire is equal in magnitude and opposite in direction, and the current vector sum detected by the zero-sequence current transformer is zero, so the leakage protection switch does not act. When a leakage fault occurs in the circuit, such as someone getting an electric shock or the insulation of electrical equipment being damaged, causing current to leak to the ground, part of the current will flow into the ground through the leakage path, making the current in the live wire and neutral wire no longer equal. The zero-sequence current transformer will detect this residual current and convert it into a voltage signal. After amplification and processing, the voltage signal triggers the latch circuit, making the thyristor conduct, thereby driving the relay to act and cut off the circuit power, realizing the leakage protection function.  

 Application Scenarios  

- **Household Electricity**: It can be installed in the household distribution box as the main switch or branch switch to provide leakage protection for various household electrical appliances such as electric water heaters, washing machines, refrigerators, and air conditioners, ensuring the personal safety of family members and the normal operation of electrical equipment.  

- **Commercial Places**: It is suitable for the protection of electrical circuits in commercial places such as small stores, offices, and restaurants, preventing safety accidents caused by leakage and protecting the safety of personnel and property.  

- **Industrial and Civil Buildings**: In the electrical systems of some small industrial plants, warehouses, and civil buildings, this leakage protection switch can also be used to protect electrical equipment and lines, ensuring the safe and reliable operation of the electrical system.  

 Installation and Use  

- **Installation Location**: It should be installed in a dry, ventilated place that is easy to operate and maintain. It is generally recommended to install it in a distribution box at a height of more than 0.8 meters from the ground to prevent water droplets or dust from entering the interior of the protector.  

- **Wiring Method**: For the 1P+N leakage protection switch NL18-20/20A, the wiring must be carried out strictly in accordance with the switch identification requirements. That is, the live wire is connected to L or the terminal without identification, and the neutral wire is connected to the terminal marked with N. Ensure the wiring is firm and reliable to avoid looseness.  

- **Use Precautions**: Before use, check whether the appearance of the leakage protection switch is intact and whether there is any damage or deformation; press the test button regularly to check whether the action of the leakage protection switch is normal; if the leakage protection switch trips, first find out the cause, eliminate the fault, and then close the switch again. Forcible closing is strictly prohibited.