Throw away your relays

John Belshe
Product Marketing Manager – Molded Case Circuit Breakers
ABB Electrification Business

If you appreciate the wisdom of combining the fax, scan, and copy functions into a single device, the benefits of combining the function of relays and meters in your breakers should be crystal clear. Read more about the benefits of smarter breakers.


Most people who work in an office have probably noticed some of their equipment has disappeared. Fax machines and scanners are becoming increasingly scarce because they’re more often being integrated with the copier in an all-in-one device. The same thing is increasingly occurring when it comes to electric control panels. Device count is decreasing as functions are combined into a smaller number of smarter components.A perfect example is the ever-more-capable breaker. They continue to perform their basic function of interrupting current flow when a fault is detected. But higher-end, low-voltage breakers from some suppliers not only perform that function with far more precision and versatility, but also incorporate the functions of other devices, including relays and meters.

The creates four big benefits for panel makers.

Reduces costs

Of course, there’s a premium to pay for these more- capable breakers, but the cost differential can be instantly overcome with savings for devices or components that are eliminated. In installations that include an external meter, for example, you more than recover the added cost by relying on the breaker to do the metering.

If you appreciate the wisdom of combining the fax, scan, and copy functions into a single device, the benefits of combining the function of relays and meters in your breakers should be crystal clear. Read more about the benefits of smarter breakers.

“The breakeven point when it comes to relays is about two components,” says John Belshe, an ABB product marketing manager for circuit breakers. “In panels with less than two relays or metering, you won’t see immediate cost savings. When you get beyond two relays or have an expensive relay, then a circuit breaker that replaces them is likely to make immediate financial sense. And even in situations where the upfront cost isn’t justified, the additional benefits described below may make a smart breaker the better choice.”

There are also cost savings related to spares. Instead of stocking relays, meters, and breakers, the only device on the shelf is the breaker.

Enhances capability

Smarter breakers, with their integrated I/O, can eliminate a lot of analog signaling by triggering things like external alarms. The breaker can be configured, for example, to simply sound an alert at a certain threshold for voltage, but to trip when it reaches a different threshold.

In some ways, the breaker acts like a smart phone. You buy it with certain features and functions baked in but add apps to expand and tailor the features. Extra logic is a just a download away. Not only are these breakers born smarter, but you can continue to teach them new tricks throughout their life.

“It’s nice knowing that if you develop a new problem like a harmonics issue a few years after the panel is in place, you don’t have to add or swap components to deal with it,” says Belshe. “I can go to the marketplace and buy the needed add-on programming, just like buying an app.”

While hard to find now, it won’t be long until panel builders and users will be able to add more advanced capabilities to their breakers, like load shedding.

Increases simplicity and reliability

Fewer devices means fewer things to do inside the panel: less installation time, wiring, and configuration. Fewer connections and devices also mean increased panel reliability and decreased need for skills or training to work on the panel. Free configuration software that connects to the breaker via USB or Bluetooth vastly simplifies the setup of breakers, even with complex features. And the ability to replicate similar configurations greatly speeds commissioning.

“I know from the plants and panel shops I deal with that this helps them deal with some of the shortcomings of so many new employees being fresh out of school,” Belshe says. “Those new employees have to come up to speed with the different types of relays, the intricacies of meters, and learning how these devices need to come together. Smarter breakers reduce training and lower the skill requirements for new employees.”

Adding both simplicity and safety is the ability to interact with some of these breakers remotely via Bluetooth. Technicians can see inside the breaker from well outside the arc flash zone. That includes not only checking breaker status and viewing event history, but also making changes to configuration.

“For people who have security concerns about Bluetooth connectivity, these breakers include the ability to turn off that capability,” Belshe explains. “In that case, technicians can connect via standard industrial protocols via Modbus or PROFIBUS, just like plugging into the commissioning software.”

With a multi-function device like these smart breakers, there is the more-eggs-in-one-basket concern. When there’s a problem with the breaker, replacing it will be more costly than replacing a relay. But the other side of the coin is how quickly a problem can be corrected.

“When there’s a panel issue, you spend much less time running down and correcting the problem,” Belshe says. “Instead of spending hours trying to figure out what’s going on, the breaker can pretty quickly tell you. Correcting the problem is often as simple as popping a new breaker in. Any breaker programming can be loaded using copy/ paste from the original breaker. Smarter breakers get you back online more quickly.”

Creates space

And, of course, one of the most obvious benefits of relying on your breakers to do more things is that there are fewer devices taking up valuable space inside the panel. In applications where space is tight, this can be a critical benefit. Even in applications where you have all the room in the world, smaller panels mean less sheet metal, and that means lower enclosure costs.

A smarter choice

“For ABB, these smarter breakers represent the migration of technology developed for our larger breakers,” says Belshe. “We took that technology and programming and adapted it – plus some additional enhancements – to low-voltage breakers for power-control panels. Since it was a case of modifying existing technology instead of creating new, that helped reduce the costs for the smaller, smarter breakers and also provided a new product that’s basically already field-proven.” Obviously, these smarter breakers are overkill in many applications. But in states with more- extensive requirements for metering like California and areas where power-providers have deployed sophisticated cost/use schemes, these smarter breakers are a gamechanger.

It’s probably worthwhile for most panel makers to weigh all the benefits to see whether it makes sense for them to throw away their relays and rely instead on the current generation of smarter circuit breakers.