When we talk about the different types of circuit breakers used in houses, single-pole and double-pole breakers come to mind. There are also AFCI and GFCI breakers designed to prevent arc faults and ground faults, respectively.
In truth, though, they can still be further classified based on their interrupting mechanism. If we do that, we get five main types: Gas, Oil, Hybrid, Air, and Vacuum.
Continue reading to learn each one extensively.
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Standard Classifications of Residential Circuit Breakers
The different types of breakers mainly revolve around these five, especially if it pertains to fixing electrical issues. Single-pole and double-pole electric breaker types fall under the “garden-variety” category for their relative popularity and wide residential application, while AFCIs, GFCIs, and Dual-Function are more specialized.
All in all, these are the most widely used types of residential circuit breakers:
1. Single-Pole Circuit Breakers
With a single switch and thinner size, these are the old circuit breaker types you see in panels. Single-poles provide a 120-volt service and have amp ratings that range between 15 to 20 amps.
As long as the circuit doesn’t require more than that and the appliances are non-heating, electricians will recommend these instead of upgrading to double-poles immediately.
2. Double-Pole Circuit Breakers
These stand out when compared to their single-pole counterparts because they’re twice as large and require as much more room in a panel. Unlike single-poles, double-poles provide a 240-volt service.
They’re meant to serve power-hungry lines that single-poles can’t handle since their amperage capacity ranges from 20 to 60 amps.
Read more detailed single pole vs double pole comparison here.
3. GFCI Breakers
These became fairly common in homes from 1971 onwards due to them becoming a requirement in swimming pools and other wet exterior areas. In 2020, the requirements were updated to include other rooms where water is present like kitchens and bathrooms.
They’re termed as ground fault circuit interrupters because they function like standard breakers but can also prevent ground faults, which are more prevalent in wet environments and may lead to electrocutions.
4. AFCI Breakers
AFCIs only became required in 1999. Arc fault circuit interrupters, as their name suggests, prevent arc faults. These kinds of faults are likely to happen when wires and terminals get damaged.
Many electricians favor bedrooms and living rooms as places for AFCI protection, even though arc faults affect the home’s electrical system.
5. Dual-Function Breakers
Simply put, these fulfill the purpose of both AFCI and GFCI breakers in that they can protect against arc faults and ground faults simultaneously. Manufacturers like Eaton, GE, and Siemens are a few of the more established brands that first offered dual-function breakers.
Nowadays, you can buy dual-function plug-on neutral breakers for breaker box specializing in that particular type of breaker. They’re recommended in newer homes for their easy installation and close to complete protection against most electrical hazards.
Types of Circuit Breakers Found in Industrial Settings
For a more technical categorization that’s applicable to an electrical engineer, here are the five breaker switch types based on how they perform their protective features. Industrial and commercial complexes also use these to prevent electrical hazards, but on a more comprehensive scale.
These are called SF6 (sulfur hexafluoride) gas breakers because they use that particular type of electronegative gas to perform their function. They’re able to safeguard the electrical lines of facilities against possible damage from lightning.
In layman’s terms, they quench electrical arcs (much like a standard breaker) by relying mostly on the said gas. The circuit breaker releases SF6 once the fault occurs, preventing the arc from progressing.
Hitachi is one of the largest creators of this type of circuit breaker and continues to see robust applications in the United States. It’s ideal for high voltage systems.
Oil circuit breakers have been around for a while and are actually the earliest forms of these nifty gadgets. Many companies still prefer them for their affordability and no-nonsense performance.
Much like gas breaker switch types, these breakers use oil to “quench” the arc. Most breakers have two contacts, which, once reached by the arc, will open and give access to the oil deposited within their respective constructions. The oil dissolves the arc.
The amount of oil stored in the breakers depends on the total voltage required by the system. Some can do with minimum amounts while others can’t operate without a substantial deposit.
This is another heavy-duty circuit breaker that can handle up to 10,000 amps and voltages up to 450V, making it ideal for most factories, ships, and industrial and commercial buildings. This breaker could directly use air or use that air to trigger the contacts responsible for interrupting arcs.
The most preferred sub-type of this breaker is the said air blast version since it is able to quench arcs quicker, is easier to maintain, and, unlike oil, isn’t flammable.
These circuit breakers read current ratings like most types of breakers. The only difference is that they have a vacuum chamber where the arc will be directed once abnormal electrical conditions arise.
A vacuum has high arc-quenching capabilities, and this breaker uses that to the fullest. Usually, they have an empty chamber for it. They bring numerous perks, the most significant of which are their compact sizes, silent operation, zero risk of fire, and long lifespan.
Any circuit breaker that combines the different interrupting mechanisms explained here can be considered a hybrid breaker. For example, this Kawasaki invention incorporates a braking resistor, vacuum interrupter, and SF6 interrupter with multiple primary contacts to divide the current and break it.
Another good example is the hybrid DC circuit breaker, which has been lauded for its lightning-fast fault interrupting mechanism. I’m talking about being able to interrupt currents as high as 200 amps in mere milliseconds!
Different types of circuit breakers impart their protection in myriad ways, handle different voltages and amperages, and are, hence, ideal for their intended application. You may encounter more classifications online, but these are the ones that are mainly used in the US.
The information shared here should help you identify circuit breaker type that is available to you.
I am Andrew Wright. I established this blog after eight years of experience designing, installing, and maintaining electrical power systems. I love my job, and I have always wanted to offer others the necessary help so they can take care of their houses.