Hydraulic-magnetic circuit breakers provide optimal power protection

Ryan Sheahen, the product manager for Sensata’s electrical protection and power control products, joined us to talk about the various types of circuit breakers available and the unique features and benefits of hydraulic-magnetic circuit breakers, which lend themselves to an extensive variety of power electronics applications in a wide range of industries. 

Hi Ryan. Please introduce yourself and tell us about your role at Sensata Technologies.

I’m Ryan Sheahen, the product manager for Sensata’s electrical protection and power control products, which includes our Airpax line of hydraulic-magnetic circuit breakers. I’ve got a BS in Mechanical Engineering Technology from Purdue University and have been with Sensata for five months.

Please also provide us with a brief introduction to Sensata.

Sensata Technologies is a global industrial technology company that develops, manufactures, and sells sensors and sensor-based solutions, including control systems, for mission-critical applications. With a rich history spanning over 100 years, Sensata has established itself as a leader in the industry, known for its innovation, quality, and reliability.

You joined us today to talk about circuit protection in harsh environments. Can you please tell us more about hydraulic-magnetic circuit breakers and how they differ from other circuit protection solutions used in harsh environment applications?

At their core, circuit breakers perform a very simple task: providing protection for electrical and electronic equipment from damaging or destructive overloads. Most electrical and electronic devices cannot distinguish between normal loads or overloads, and circuit breakers provide a protection solution that can reliably distinguish between the two. 

Circuit breakers are found in a variety of applications including, data centers, telecom equipment, military electronics, HVAC systems, generators, and many more. 

There are four main types of circuit breaker technologies: thermal, thermal-magnetic, solid-state, and hydraulic-magnetic. Sensata specializes in hydraulic-magnetic circuit breakers, but it’s important to know a little bit about each type of circuit breaker, as these four different technologies have trade-offs between durability, speed, and performance. So, that knowledge can be very helpful when it comes to selecting the best circuit protection solution for your unique application needs.

• Thermal circuit breakers use a bimetallic element that reacts to unequal expansion rates of the two metals in the strip by bending, which moves the switch and opens the circuit to safely interrupt the flow of electricity. They have a simple, low-cost design but are lacking when it comes to durability.

• Thermal-magnetic circuit breakers combine thermal circuit breaker technology with magnetic technology to achieve faster disconnection times at higher overcurrents. They have the same shortfalls as thermal breakers and have reduced inrush current capabilities.

• Solid-state circuit breakers are semiconductor devices that control the amount of power supplied to a load while performing supervisory and diagnostic functions that identify overloads and quickly interrupt short circuits. These breakers are more expensive than thermal circuit breakers, rely on external power, and create excess heat, EMI, and power losses. Sensata also offers a wide range of solid-state breakers within our Crydom brand portfolio, but that’s a topic for another day.

• Hydraulic-magnetic circuit breakers use magnetic flux to sense an overcurrent and incorporate a hydraulic tube that gives these breakers the same tipping performance across all ambient temperatures, ranging from extreme heat to extreme cold, which his their most unique and valuable characteristic. But they also provide several other advantages compared to competing technologies. For example, hydraulic-magnetic breakers react faster than thermal and thermal-magnetic circuit breakers at overloads, and they combine the capability to switch power ON and OFF with overcurrent protection.

What industries and applications benefit the most from hydraulic-magnetic circuit breakers?

Hydraulic-magnetic breakers can be found in a wide variety of applications across global markets. In HVAC systems, they are used to protect compressors and fan motors during start-up and normal operation. In datacenters, you will find several breakers inside the power distribution units (PDUs) that provide power to the server racks and add another layer of circuit protection. In telecom infrastructure, circuit breakers are found in universal power supplies and provide protection for sensitive and expensive downstream telecom equipment. You’ll also find them in military and industrial applications that require ruggedness and reliable performance across a wide range of ambient temperatures.

What are important characteristics to consider when selecting a circuit breaker for use in harsh environments?

There are several of characteristics to consider when selecting the right hydraulic-magnetic circuit breaker for your application. Factors like size, steady-state current and voltage, overload current, trip-curve characteristics, and required agency approvals are key considerations for virtually every application.

For applications in harsh and otherwise demanding environments, you’ll typically want a breaker that is hermetically sealed, like our AP Series, which is part of our Airpax line. Hermetically sealed breakers are completely sealed from the environment to prevent moisture, dust, and other contaminants from entering and ensure reliable operation. For applications subject to the most extreme conditions, like some military applications, you could consider using an M39019 Series breaker, which is hermetically sealed and QPL approved for use in life-critical U.S. military applications. Sensata also offers these as part of our Airpax line. 

Please introduce us to Sensata’s Airpax Series of circuit breakers.

 Sensata’s Airpax Series circuit breakers are the broadest portfolio of hydraulic-magnetic circuit breakers on the market, which allows us to address the widest range of applications with best-in-class performance, quality, and customer support. Airpax hydraulic-magnetic circuit breakers are available with a wide variety of packages, mounting types, terminations, handle types, and other features that allow users to construct the ideal solution for each application. The line includes circuit breakers rated for current values extending from 0.1A to 1,200A and recognized and listed by globally regulatory agencies, including UL, TUV, CCC, CSA, and various militaries.

I’ve already touched on our hermetically sealed AP Series Airpax products, but we have many other products — like the SNAPAK, IAG/IUG/CEG/LEG, and IAL Series — that also have unique features and benefits designed to help our customers overcome common challenges related to protecting both personnel and equipment.  

Can you tell us more about the Airpax SNAPAK Series?

Snapak breakers are available in single- and two-pole configurations and have a maximum interrupt capacity of 1kA. They are also rated to both 65VDC and 250VAC, which means that our customers don’t need to order separate breakers for AC and DC applications. And the fact that one Snapak breaker can be used for both helps customers further reduce inventory costs.  

This series comes standard equipped with quick-connect terminals designed to reduce installation time but also offers other mounting hardware options. Customers can also choose from a range of handle types and colors and operating characteristics.

Snapak is really the Jack-of-all-trades when it comes to hydraulic magnetic circuit breakers and can satisfy the demands of applications ranging from appliances to medical equipment and vending machines.  

Please introduce us to the Airpax IAG/IUG/CEG/LEG Series.

The IAG, IUG, CEG, and LEG Series breakers are a bit larger that the Snapak Series. They are available with up to six poles and offer higher current ratings — up to 50A — with a 5kA maximum interrupt capacity.

The most unique feature about this line of breakers is its trip-free functionality, which means these breakers will trip in the presence of an overload, even if the handle is held in the ON position. The delay mechanism senses the fault and keeps the contacts open regardless of handle position. This prevents a maintenance technician from manually flipping these breakers on during an active equipment overload condition and reliably protects personnel from accidental shock. These breakers will remain open until the fault has been removed.  

This trip-free feature is a requirement for UL1077 for supplementary protectors and makes this series ideal for protecting single pieces of telecom, lighting, and rail equipment. In fact, these breakers are widely used in rail equipment throughout Europe.  

Please also tell us about the Airpax IAL/CEL/LEL Series.

The IAL, CEL, and LEL Series breakers are part of our 214 Family and are slightly larger than the IAG, IUG, and other series we talked about earlier. They are rated for up to 100A with a maximum interrupt capacity of 10kA.

The 214 Family is designed to meet a broad range of industrial applications across all global regions. Each region of the world requires different safety agency approvals for equipment to be sold into that market, and the 214 Family offers configurations that are approved to some of the most common agency requirements, including TUV, IEC, UL, CSA, and CCC.

One of the more unique features of the IAL, CEL, and LEL Series breakers is that they’re available with auxiliary switch options available, which allow for remote monitoring of the breaker’s OPEN or CLOSE status. The auxiliary switches are electrically isolated from the protector’s circuit but will actuate simultaneously with the main breaker contacts and provide a signal that communicates whether the breaker is open or closed. This feature minimizes the need for manual inspections, which is especially beneficial in hazardous environments and hard-to-reach areas. It also can provide diagnostics by monitoring the breaker’s operations over time and can help predict potential failures and future maintenance needs, which improves overall system reliability.

It’s this unique functionality that makes the IAL, CEL, and LEL Series ideal for applications like universal power supplies, telecom equipment, portable generators, marine and boat applications, and datacenters.

Are there any success stories you’d like to share about Sensata’s Airpax hydraulic magnetic circuit breakers?

We’re always partnering and collaborating with our customers to find the right Airpax solutions to meet their application requirements.

We’ve been working with a leading power distribution unit manufacturer to incorporate several 214 Family Airpax circuit breakers into their newest product, which will provide circuit protection for the next generation of AI datacenters.

We’re also partnering with a global leader in the rail industry on about a dozen projects in which they’re replacing thermal magnetic breakers with more robust, reliable hydraulic-magnetic circuit breakers. They really value the stable and precise performance of hydraulic-magnetic breakers over the wide range of ambient temperatures and rugged environments that rail cars are subjected to. 

Is there anything else you’d like our listeners to know about Sensata, its circuit breakers, or its Airpax line of hydraulic magnetic circuit breakers?

When it comes to choosing circuit protection for your applications, the Sensata Airpax brand of hydraulic-magnetic circuit breakers really stands out. We have a legacy of quality, reliability, and innovation, and our comprehensive portfolio caters to widest range of applications and industries.

Like RS, we also believe in partnering with our customers, from concept through to design, implementation, and maintenance. Our engineering teams work closely with customers to understand their unique requirements and challenges and find the perfect solution. When your brand and reputation is on the line, you can trust Airpax circuit breakers to give you peace of mind. We look forward to partnering with you soon.

Protect your powered equipment and personnel with Sensata and RS

Sensata Technologies is a global industrial technology company striving to create a safer, cleaner, more efficient, and electrified world. Through its broad portfolio of mission-critical sensors, electrical protection components, and sensor-rich solutions, Sensata helps customers address increasingly complex engineering and operating performance requirements.

RS offers an extensive selection of Sensata solutions, including its extensive Airpax line of hydraulic-magnetic circuit breakers, as well as a wide variety of other circuit protection solutions, relays, sensors, and industrial controls. RS also provides comprehensive customer support for Sensata solutions, helping customers identify, procure, implement, and maintain the best solutions for their individual application needs. To learn more about Sensata solutions available at RS, please visit the links embedded here. For support, please contact your local RS representative at 1.866.433.5722 or reach out to the RS technical support team.