Scope of application

The EXB3-125 series Miniature Circuit Breaker (hereinafter referred to as “circuit breaker”) can be used in power facilities and electrical equipment circuit with AC 50Hz, rated voltage up to 400V, and rated current up to 125 A, to offer overload and short-circuit protection for overcurrent protection, and can be also used for the infrequent on-off control. The feature of signal controlling tripping can be available to satisfy special needs of long-distance controlling of breaking circuits or automatic signal controlling breaking. Nowadays, this feature is widely used together with IC card electricity meter to control the breaking of circuits.

This series of circuit breakers meet the requirements of GB/T 14048.2 and other standards.

Normal working conditions

1. The upper limit of ambient air temperature shall not exceed +40°C, the lower limit shall not be lower than -5°C, and the average-value VI within 24 hours shall not exceed +35°C. 

2. The altitude of the installation location shall not exceed 2,000 m. When the ambient temperature changes, its rated current value needs to be corrected, correction factor. 

3. The relative atmospheric humidity does not exceed 50% when the ambient air temperature is +40°C, and a higher relative humidity is allowed at a lower temperature. The average maximum relative humidity in the wettest month is 90%, and the average maximum temperature in this month is +25°C. Measures shall be taken to deal with the occasional condensation due to temperature changes. 

4. Contamination grade: Grade 3. 

5. The installation category: Grade II and III. 

6. Install with 35mm standard guide rail. 

7. This MCB shall generally be installed vertically, and when the handle is upward, the power is on. 

8. The installation place shall have no significant shaking and impact vibration.