Circuit Breakers: Differences and Standards to Know


Although it can be difficult to understand what the different types of circuit breakers are, there are some that you should know about. Even if you don’t have an electrical background, having this knowledge under your belt can definitely help you if you ever have to purchase a circuit breaker yourself.

Classification of Circuit Breakers

Circuit breakers are mostly classified due to the different mechanisms they have. For example, a best 50 amp double pole breaker is not going to have the same inner workings as a 20 Amp one pole. Their categorizations are based on:

  • Voltage
  • Interruption Mechanism
  • Installation Location
  • Features or Design

But what do each of these features mean?

Circuit Breaker Voltage

Voltage is the amount of power that can pass through the breaker. These typically fall into three categories: high-voltage, medium-voltage, and low-voltage. This allows them to be used for different applications. For example, a high-voltage circuit breaker would be best suited for power transmission lines, while low-voltage circuit breakers are the kind you would find in your hardware store for purchase.

Interruption Mechanism

This is the mechanism that is used to cut the flow of the current in the circuit breaker to prevent it from overloading. There are usually four main types.

  • Air circuit breakers: air is used as the primary insulator and interrupting mechanism. Air blast circuit breakers use a blast of air to cause this interruption, while magnetic breakers use a magnetic field to interrupt the circuit.
  • Oil circuit breakers: mineral oil is used to break the arc and is usually preferred over air because of its insulating properties.
  • Sulfur hexafluoride circuit breakers: Sulfur Hexafluoride (SF6) gas is used because it has twice the insulating properties as air. It is mostly used in both medium- and high-voltage circuit breakers.
  • Vacuum circuit breakers: these are mostly used in high-frequency circuit breakers, and use electrodes in the interruption process.

Installation Location

Because circuit breakers are used in different installation locations, they are classified as inside or outside. Indoor circuit breakers tend to be installed in protected enclosures so that they can be kept safe away from weather conditions. Outdoor circuit breakers, on the other hand, do not require any protection or roofing. They already have stronger arrangements installed on them so that they’re not affected by the elements or wear and tear.

Identifying the Right Circuit Breaker

If you ever need to buy or change a circuit breaker, there are three things you should take into account. You have to look at the voltage rating, the current rating, and the trip curve. The voltage rating refers to the overall voltage rating of the electrical system. This is the highest voltage that can be applied across all end ports.

The current rating refers to the amperage that is 120% of the required load. This helps to set off the effects of any heat generation that might occur while there is current flow.

The trip curve is also known as the time current curve, which is a graphical representation of the expected behavior of a circuit breaker. This is usually provided by the manufacturer so that users can choose the right devices for their needed performance.

Circuit breakers are not only complex, but they’re also quite delicate so you should be sure of the right one you’re getting. Any mistake can result in disastrous and expensive consequences. It’s best to speak with a certified electrician to ensure you’re getting the right circuit breaker for your purposes.

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