Necessity of circuit breakers in photovoltaic systems

  Circuit breaker is one of the indispensable components in the photovoltaic system, two main functions: 

  1: Electrical isolation function, used to cut off the electrical connection between photovoltaic modules, inverters, power distribution cabinets and the grid during installation and maintenance, to provide operators with a safe environment,which is generally realized by operators actively.

  2. Safety protection function, when the electrical system has overcurrent （circuit breaker is too small or the quality is not good, resulting in long-term overload operation and easy heating and tripping）,overvoltage (1. Wrong selection of the rated voltage of the circuit breaker; 2. When the power of the photovoltaic system is greater than the power used by the load, the inverter will increase the voltage and send power to the outside.),short circuit overtemperature (The rated current marked by the circuit breaker is the maximum current that the device can pass for a long time at a temperature of 30 degrees. The current will decrease by 5% for every 10 degrees increase in temperature. The circuit breaker is also a heat source because of the existence of contacts)and leakage current, it can automatically cut off the circuit to protect the safety of people and equipment. This action is automatically realized by the switch.

  During the operation of photovoltaic power plants, switches often trip, mainly because the switches may have overcurrent, overvoltage, overtemperature, and leakage current. A switch trip of the photovoltaic system will directly cause the system to not generate electricity and cause economic losses. If it is a power station that has been installed for a long time, it may be a circuit wiring problem or a switch aging problem, which needs to be discovered and replaced in time during daily equipment inspections. If it is a newly installed power station, there may be problems such as improper switch selection, poor line insulation, poor transformer insulation, etc. We need to pay as much attention as possible in the early stage equipment selection of the power station.