Circuit Breaker Switchgear Controls: What are they and how do they Work?

Switchgear controls are designed to isolate electrical equipment from normal electrical currents for maintenance purposes, or from abnormal currents (i.e. faults) that could damage it, and potentially cause a fire. Switchgear is typically seen in the form of fuses, electrical disconnects, circuit breakers, and sometimes a combination thereof. The type of gear a company has depends on several factors, such as voltage level, the type of equipment being isolated, and the gear's environment, to name a few. In this entry, we look at circuit breaker models according to their voltage type, construction type, and insulation design.

1. Voltage Type

As with other types of switchgear, circuit breakers are categorized in terms of the voltage they handle: low (<1000 volts AC), medium (1000-35000 volts AC), or high (>35,000 volts AC). As one would suspect, low voltage gear is typically found in residential and low power commercial structures, while medium and high voltage are commonly found in higher power commercial and high power industrial structures.

2. Construction Type

Because electrical equipment is used in a variety of scenarios, breakers have various construction types that allow them to meet the demands of their environment and any rules associated therewith. Among the many construction designs for circuit breakers are: outdoor design, marine design, metal enclosed design, metal clad design, live front design, and dead front design.

3. Insulation Design

The most distinguishable aspect of circuit breakers is their insulation design, which comes in five types: oil, which extinguish an arc by interrupting it with a jet of oil; gas (SF6), which stretch an arc so the SF6 can then extinguish it; vacuum, which extinguish an arc by stretching it; air, which extinguish an arc with air movement; and hybrid designs, which combine two of the aforementioned designs, such as SF6 and air.

Considerations for Implementing Circuit Breakers

Each design has its benefits and drawbacks. For example, oil models are inexpensive and easy to operate, but they lack the efficiency of newer technologies. Similarly, SF6 models are highly efficient, but their expensive exceeds that of other models. The best way to choose breakers for your facility, or to see if they best meet your control needs in the first place, is to consult with a commercial power solution provider that specializes in switchgear installation, retrofitting, and maintenance.

Commercial power solution providers specializing in switchgear should offer the following services: switch gear maintenance, testing, upgrades, installation, and design of custom gear when necessary. If you haven't assessed the state of your building's switchgear in recent years, or if it currently receives less than ideal maintenance, hiring a commercial power solutions provider to assess or maintain it today could be key to preventing equipment damage and building fires.