Projoy Classroom(Lesson 2) Circuit breakers


In the last lesson, we talked about the knowledge of photovoltaic DC ioslators. In this lesson, we will continue to introduce another key component of photovoltaic power generation systems: Circuit breakers.


Circuit breaker refers to a mechanical switching device that can make, carry and break current under normal circuit conditions and specified abnormal circuit conditions. It has the function of short circuit/overload protection.

Usually, the circuit breaker can be replaced by a fuse that is matched in series with the disconnector. The only difference is that when the fuse is blown, the fuse core needs to be replaced, and when the circuit breaker is overloaded and broken, just push the switch to restore it.

Usually the circuit breaker whose rated current below 125A is called a miniature circuit breaker. 


How does the circuit breaker protect the circuit?

●When the line is generally overloaded, the overload current will cause the heating element to generate a certain amount of heat, which will cause the bimetallic sheet to bend upwards when heated, push the lever to disengage the hook from the lock, disconnect the main contact, and cut off the power;

●When the line is short-circuited or severely overloaded, the short-circuit current exceeds the instantaneous trip setting current value, and the electromagnetic release generates enough suction to attract the armature and hit the lever, make the hook rotate upwards around the rotating shaft seat to disengage the lock, and the lock will break the main contact under the action of the reaction force spring and cut off the power supply;

●Auxiliary contacts are mechanically linked contacts of the main circuit opening and closing mechanism of the circuit breaker. They are mainly used to display the opening and closing status of the circuit breaker. They are connected to the control circuit of the circuit breaker through the opening and closing of the circuit breaker, control or interlock its related electrical appliances;

●The shunt release is a release that is excited by a voltage source. Its voltage can be independent of the main circuit voltage, and it is an accessory for remote control of opening. When the power supply voltage is equal to any voltage between 70%-110% of the rated control power supply voltage, the circuit breaker can be disconnected reliably.

The circuit breaker is used to make, break and carry the rated working current and short-circuit, overload and other fault currents in the circuit, and can quickly break the circuit for reliable protection in the event of overload, short-circuit, undervoltage, etc. on the line and load.


Why Choose Projoy Circuit Breakers?

Projoy has a professional circuit breaker R&D team with many years of experience. Since the launch of circuit breaker products in 2013, it has been continuously recognized by customers. It is providing high-quality products for many world's top energy storage battery and system manufacturers. It has become a famous supplier of many mainstream energy storage battery and system manufacturers.

Among them, non-polar miniature circuit breakers are well received by the industry. Non-polar DC miniature circuit breakers rely on the new miniature circuit breaker arc extinguishing system to solve the problem of high temperature gas generated by arc extinguishing in traditional miniature circuit breakers, which causes shell rupture, poor arc extinguishing effect, and complex structure problems.


Recommend a star product?

PEBS-S series high-voltage DC miniature circuit breaker, UL certified, breaking capacity up to 10kA, maximum rated voltage 1000VDC, rated current up to 80A, non-polar design, better protection effect, electrical life up to 1500 times, mechanical life up to 20000 times.


What are the features of Projoy circuit breakers?

- A variety of product types, such as AC and DC, high and low voltage, internal and external, are widely used;

- Passed various international standard certifications: CE, TUV, CB, SAA, UL, etc., with guaranteed quality and performance;

- 5 years warranty after product sale.


Projoy will always adhere to the brand concept of "Switch To Safety", focus on the R&D and production of DC safety components, and continue to escort the development of the photovoltaic & energy storage.


That's the end of this lesson! Next lesson: Rapid Shutdown, please look forward to it~