What is a circuit breaker?

A circuit breaker refes to a mechanical switch device capable of connecting, carrying, and interrupting electric currents under normal circuit conditions, as well as connecting, carrying for a certain period of time, and interrupting currents under specified abnormal circuit conditions. It possesses the function of short-circuit and overload protection. Typically, circuit breakers can be used in conjunction with matched fuses instead of isolating switches. The only distinction is that when a fuse blows, the fuse element needs to be replaced, whereas when a circuit breaker trips due to overload, simply pushing the switch back restores it.

Generally, circuit breakers with a rated current below 125A are referred to as miniature circuit breakers.

Circuit Breakers

How does a circuit breaker ensure circuit safety?

(1) In the case of a general overload, the heat generated by the overload current causes the thermal element to bend upward, pushing the lever to disengage the latch, thereby interrupting the main contacts and cutting off the power supply.

(2) In the event of a short circuit or severe overload current, if the short-circuit current exceeds the instantaneous trip current setting, the electromagnetic trip unit generates sufficient magnetic force to attract and strike the plunger, causing the latch to rotate upward and disengage the lock. The lock, under the action of the reactive spring, interrupts the main contacts, cutting off the power supply.

(3) The auxiliary contacts are the mechanically linked contacts that are part of the circuit breaker’s main circuit switching mechanism. They are primarily used for indicating the open or closed state of the circuit breaker. By connecting them to the control circuit of the circuit breaker, they can be used for control or interlocking of related electrical devices.

(4) The shunt trip unit is a tripping device that is energized by a separate voltage source. Its voltage is independent of the main circuit voltage and is an accessory used for remote tripping of the circuit breaker. When the power supply voltage equals any voltage within 70% to 110% of the rated control power supply voltage, the circuit breaker can be reliably tripped.

The circuit breaker is responsible for connecting, interrupting, and carrying the rated working current as well as fault currents such as short circuits and overloads in the circuit. It can swiftly interrupt the circuit and provide reliable protection in the event of overloads, short circuits, undervoltage, and other conditions occurring in the circuit and the load.

Circuit Breakers

Why choose ONCCY circuit breakers?

ONCCY boasts a professional team of circuit breaker developers with years of experience. It is currently providing high-quality products to numerous top global energy storage battery and system manufacturers and has become a major supplier to the majority of mainstream energy storage battery and system producers.

Among them, the non-polarized miniature circuit breakers have received acclaim in the industry. The non-polarized DC miniature circuit breakers rely on a new arc extinction system to address issues such as high-temperature gas causing casing rupture, inadequate arc extinction, and complex structure found in traditional miniature circuit breakers.

The EDS1-63 series high-voltage DC miniature circuit breakers have a breaking capacity of up to 10kA, a maximum rated voltage of 1000VDC, a rated current of up to 63A, and a non-polarized design for enhanced protection. They have an electrical lifespan of up to 1500 operations and a mechanical lifespan of 20,000 cycles.

DC No-Polarity Miniature Circuit Breaker
DC No-Polarity Miniature Circuit Breaker

What competitive advantages do ONCCY circuit breakers offer?

  • Multiple product types, such as AC/DC, high/low voltage, internal/external installations, with wide-ranging applications.
  • Compliance with various international standards certifications, including CE, TUV, CB, SAA, UL, ensuring quality and performance.