A circuit breaker is a switching device that can close, carry and break current under normal loop conditions and can close, carry and break current under abnormal loop conditions within a specified time. Circuit breakers are divided into high-voltage circuit breakers and low-voltage circuit breakers according to their scope of use. The division of high and low voltage lines is relatively vague. Generally, 3kV or more is called high-voltage electrical equipment.
The following conditions must be met for the equipment to operate normally:
Ambient air temperature: upper air temperature +40 ° C; ○ ambient air temperature lower limit -5 ° C; ambient air temperature 24 h average does not exceed +35 ° C.
Altitude: The altitude of the installation site does not exceed 2000m.
Atmospheric conditions: The relative humidity of the atmosphere does not exceed 50% when the ambient air temperature is +40 °C; it can have a higher relative humidity at the lower temperature; the monthly average maximum relative humidity of the wettest month is 90%, while the month The monthly minimum temperature is +25 ° C, taking into account the condensation that occurs on the surface of the product due to temperature changes.
Pollution degree: Pollution level is 3.
1. It should be able to monitor the integrity of the control circuit protection device and its jump and closing circuit to ensure the normal operation of the circuit breaker;
2. It should be able to indicate the position status of the normal closing and opening of the circuit breaker, and have obvious indication signals during automatic closing and automatic tripping;
3. After the closing and tripping are completed, the command pulse should be released, that is, the power supply for closing or tripping can be cut off;
4. When there is no mechanical anti-jump device, an electric anti-jump device should be installed;
5. The circuit breaker's accident trip signal circuit shall be wired according to the “non-corresponding principle”;
6. A warning signal shall be installed for equipment that may have abnormal working conditions or faults;
7. The power supply of the spring operating mechanism and the manual operating mechanism can be DC or AC, and the power supply of the electromagnetic operating mechanism requires DC.