Understanding Low-Voltage Industrial Circuit Breakers

The point of a circuit breaker is to keep too large of an amount of current out of a part of an electrical circuit. industrial circuit breakers complete the same task for a higher voltage level. Industrial circuit breakers are an incredibly important part of a piece of equipment or an entire electrical system’s safety protocol.

Low-Voltage Industrial Circuit Breakers

Industrial circuit breakers are categorized by voltage level. The IEEE divides voltage levels into four classes. The largest grouping of industrial circuit breakers in place in manufacturing plants fall into the low and medium-voltage ranges.

The two main classifications of low-voltage industrial circuit breakers are “toggle” mechanism and two-step stored energy mechanism. Low voltage industrial circuit breakers manage less than 1000 VAC. The industrial circuit breaker’s protection requirements will vary based on the circuit breaker’s specific location within the power system as well as the type of equipment that needs to be protected.

Miniature Circuit Breakers (MCB) and Molded Case Circuit Breakers (MCCB) are both low-voltage industrial circuit breakers that are thermal or thermal-magnetic in operation. Low-voltage power circuit breakers can be mounted in multi-tiers in switchboards or switchgear cabinets. The MCB has a rated current of no more than 100A while the MCCB has a rated current of up to 1000A.

Low-voltage molded case and power circuit breakers may have electrical motor operators that allow the circuit breakers to be tripped via remote control. Low-voltage industrial circuit breakers are also made for DC applications. Special breakers are required for DC due to the type of arc generated. A DC industrial circuit breaker will have coils which generates a magnetic field that stretches the arc when the need to interrupt the DC arises.

When an engineer has a full understanding of all the differences in the various standards, the engineering can make the best decision possible regarding which type of industrial circuit breaker should be used. Additionally, it is also important that the engineer understand all the industrial circuit breaker standards fully so the proper installation and use procedures are followed properly in order to ensure the industrial circuit breakers are used safely.