With the development of electronic technology, electronic outlet units are widely used in plastic case circuit breakers. At the same time, with the enhancement of people's awareness of personal electric shock and electric fire protection, more attention has been paid to the use of grounding protection function of plastic case circuit breaker. Therefore, the difference between grounding fault protection and residual current protection of plastic case circuit breaker conforming to IEC60947-2 standard is clearer.

First, the meaning of protection is different:

1. Ground fault protection: protection against faults caused by accidental connection between live conductors and the earth;

2. Residual current protection: Protect the current vector of each phase (including neutral line) and fault current which is not zero in low voltage distribution line.

2. The protection function is different:

Ground fault protection defined by circuit breakers (ACB, MCCB) in line with IEC60947-2 standard is strictly a part of over-current protection in circuit breakers. When a single-phase short-circuit fault occurs in the system, due to various external factors, the short-circuit fault current to the ground is likely to be less than the rated current value of the circuit breaker, at this time, the circuit breaker will not be able to effectively break the fault current. Long-term faults will also cause the ground voltage of the non-fault phase to rise, and the maximum line voltage of the system can be reached. At the same time, it may cause other parasitic disasters.

Residual current protection defined by circuit breakers (ACB, MCCB) in accordance with IEC 60947-2 standard mainly provides protection against electric shock hazards according to the requirements of standard appendix B, while providing additional protection for over-current protection devices of circuit breakers which can not be detected, but may cause fire or other hazards for a long time.

3. Different requirements for protection:

Due to the different functions of grounding fault protection and residual current protection, the protection requirements are the same.

The setting of grounding fault protection action current of circuit breaker is mainly based on the rated current in of circuit breaker, usually in the range of (0.2-1) In. At the same time, the action time is also adjusted.

The action current setting of the residual current protection in accordance with Appendix B is set by the electrical appliance manufacturer according to the standard within the range of 6mA-30A, which is set by the user. At the same time, it can adjust and set the action time.

Fourth, the selection criteria of the two types of circuit breakers are different:

Because MCCB plays a connecting role in the low voltage distribution system, in order to ensure the safe and efficient operation of the system, it is also suitable to select the electronic outlet unit products with grounding protection in the selection of branch over-current protection components without the requirements of personal electric shock protection and electrical fire protection.

When choosing plastic case circuit breaker of electronic outlet unit with residual current protection module for branches requiring physical electric shock protection and electrical fire protection, attention should be paid to closing the grounding protection of electronic outlet unit to ensure the function of residual current protection.

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Classification of Molded Case Circuit Breakers and Related Parameters

Introduction to the Concept of DC Molded Case Circuit Breaker

The Difference between Plastic Shell Circuit Breaker and Intelligent Universal Circuit Breaker

This article is reproduced by Hangkai Electrical Appliances (Shanghai) Co., Ltd. (http://www.hangkaiele.com/) in the old electric Hu sun-dried goods.