Safety and efficiency are the key to successfully operating electrical systems and the electrical component known as the circuit breaker, assists with just that. In 1879 the famous inventor, Thomas Edison, became the first person to patent the idea of using the “Circuit Breaker” to protect lighting circuit wiring from accidental short circuits and overloads. Fast forward to the modern day and electrical engineering has progressed so rapidly that we now have a huge variety of circuit breakers ready for industrial purposes. One of these variants include the Insulated and Molded Case Circuit Breakers which can be seen available on the Surplus Record catalog.
Within the following Surplus Record buyers guide, we’ll cover some of the basics regarding how the Insulated and Molded Case Circuit Breaker functions and some of their primary purposes. Additionally, some tips and tricks will be provided to help with the smooth purchase process of new and used circuit breakers as well as some notes that buyers should be aware of when they are on the lookout for used circuit breakers for sale.
What is a Circuit Breaker?
A circuit breaker is defined as an automatic switch designed device which is used for stopping the flow of current within an electric circuit as a safety measure. An active circuit breaker will detect faults and immediately discontinue the flow of electricity to prevent damage to machinery or systems or to prevent physical injury to the operator.
In the Surplus Record catalog one can view:
Insulated VS Molded Case Circuit Breakers
Molded case circuit breakers (MCCB) house all their electrical components within a well-insulated molded case. They are durable and highly adaptable as they are designed for use within a range of environments. MCCBs protect against sudden short circuits, ground faults, and thermal overloads using thermomagnetic and electromagnetic systems to trip the breaker and disrupt the flowing electricity.
Insulated case circuit breakers (ICCB) on the other hand, also enclose all components within an insulated case. The difference between MCCB and ICCB is that ICCB includes a 2-step stored energy mechanism and are available in larger frame sizes and higher amp ratings than MCCBs. ICCB curvy breakers are also constructed entirely of plastic with no metal components, even on the frame.
Other Types of Circuit Breakers
Today, circuit breakers come in many different kinds of configurations and are widely used in both consumer and commercial electrical applications where an overload could lead to a fire risk. During an overload event, electricity will arc, which could cause combustion if not contained. All circuit breakers feature an arc extinguisher, which does just that. They also all have protective frames, a means of opening and closing the breaker, contacts that let electricity flow when closed, and trip units that help manage lengthy overloads. Unlike fuses, circuit breakers can be manually or automatically reset after a short circuit.
Low-Voltage Circuit Breakers
Possibly the most common kind of circuit breaker in residential, commercial, and industrial applications alike, low-voltage circuit breakers come in two primary types: miniature circuit breakers that manage currents up to 100 amps and molded-case breakers rated up to 2,500 amps. These circuit breakers are generally easy to service and disassemble.
Medium-Voltage Circuit Breakers
Typically rated from one to 72 kilovolts, these circuit breakers are used primarily in industrial applications and differ according to the ways they extinguish an electrical arc. Air-break circuit breakers use common atmosphere combined with electronic controls, while vacuum-break interrupters employ atmosphereless bottles. Sulfur hexafluoride breakers use their eponymous gas and require little maintenance.
High-Voltage Circuit Breakers
Rated for 72.5 kilovolts and up, high-voltage circuit breakers are primarily used in infrastructure-related electrical applications. In addition to the extinguishing methods used for medium-voltage breakers, high-voltage breakers employ bulk oil and carbon dioxide.
How does a Circuit Breaker Work?
As mentioned, circuit breakers are designed to interrupt the unstable flow of electricity to prevent unwanted damage to mechanics or as a safety measure. An active circuit breaker conducts this process through analyzing the flow of electricity through its system. If problematic electrical currents are flowing through the circuit breaker, the electromagnetic force of such electrical currents causes components inside the circuit breaker to separate, tripping the breaker and shutting off the power to the problematic circuit.
Uses and Applications
The circuit breaker is a very important part of electrical systems. MCCBs and ICCBs have slightly different uses and applications as listed below.
Molded Case Circuit Breakers:
- For low voltage industrial electrical protection with frame sizes generally between 250 to 2000 amps
- To protect against short circuits, ground faults, and thermal overloads
- For most industrial switchboards or control panels with medium voltage currents
Insulated Case Circuit Breakers:
- For low voltage industrial electrical protection between with frame sizes generally between 800 to 5000 amps
- To replace old air circuit breakers
Important Considerations Before Buying Circuit Breakers
Electrical Rating: All circuit breakers have an electrical rating (measured in either volts or amps) which states the amount of electricity that can be safely passed through the breaker. It is important for you as the buyer, to select a breaker that can handle the amount of electrical input you wish to apply to the system.
Interrupting Capacity: This refers to the maximum amount of fault current that the circuit can handle without causing failure to the entire electrical system itself. Selecting a circuit breaker to match your expected electrical fault current levels is important to maintain a healthy electrical system.
History of Maintenance: Electrical systems need maintenance and the circuit breaker component of the system is no different. Purchasing a circuit breaker with a proven history of maintenance can prevent problems down the road.
Environmental Capabilities: Different circuit breakers are designed to be more or less efficient within different environments. These environments could include the presence of moisture and high/cold temperatures. In short, try to purchase a circuit breaker ideal for its desired location.
Surplus Record: Tips and Tricks
To assist you further when searching for used circuit breakers for sale on our platform, we have attached our best tips and tricks to use when navigating.
- Make use of our Location Settings: At the top of the page, when on the list for your desired piece of equipment/machinery, enter your desired location and you’ll be taken directly to what we have available in your area.
- Looking for an Auction?: On the listing page, select the blue checkbox on your right which says “Auction” and you’ll be taken to our available products for sale via auction.
- On a Budget?: Select the toggle “Sort by Relevance” and then click “Price low to high” to view our cheapest to most expensive products for sale.
- Don’t forget the Search Bar: Already know what you are looking for? Utilize our search bar at the top of the website to find specific listings out of hundreds available.
Quick Access: Circuit Breakers
- National Switchgear | Texas
- Denver Breaker Supply | Denver
- RESA Power Solutions | California
Quick Access: Dealers Specializing in Circuit Breakers
Quick Access: Industrial Circuit Breaker Manufacturers
Our top manufactures available at Surplus Record for used insulated and molded case circuit breakers include:
Need More Help? Or further information about Industrial Circuit Breakers? Head on over to the “Wanteds” section of our website and select “Buy” at the top and “General Equipment ” for the industry. Fill out the form and a dealer that specializes in circuit breakers will get back to you ASAP. It’s free to do, and our dealers are happy to help!
