For decades, the term low voltage has been the industry’s go-to phrase for systems like building automation, security, fire alarm, access control, and communications infrastructure. But as technology continues to evolve, the National Electrical Code (NEC) is introducing a broader and more accurate term: limited energy.
While the work itself is not changing all that dramatically, the language surrounding it is. Understanding why this shift is happening and what it means for the future of connected buildings can help owners, designers, contractors, and facility teams stay ahead of the curve.
The move away from the term low voltage is less about changing how systems are installed and more about better defining a rapidly evolving industry.
According to Kyle Krueger, Executive Director of Codes and Standards for the National Electrical Contractors Association (NECA), the term low voltage has long created confusion because its meaning varies depending on the audience.
“Depending on whom you ask, the term ‘low-voltage’ means many different things,” said Krueger. “In utility transmission work, ‘low-voltage’ refers to anything under 1,000 volts. In others it can mean 48 volts or less.”
As new technologies enter the market, those definitions become even more difficult to apply consistently. One of the biggest drivers behind the terminology change is the emergence of Class 4 Fault Managed Power (FMP) systems, which deliver usable power over long distances while managing electrical hazards through continuous monitoring rather than simply limiting voltage or power at the source.
Because of innovations like these, the NEC has adopted limited energy as a broader umbrella term that encompasses traditional power-limited and low-voltage systems, along with newer technologies that don’t fit neatly into historic classifications.
The short answer: not much changes operationally today, but several industry trends are worth paying attention to.
The term low voltage is unlikely to disappear overnight. In fact, it will likely remain part of everyday industry vocabulary for years to come. However, architects, engineers, contractors, manufacturers, and code officials will increasingly encounter the term limited energy in codes, standards, specifications, and industry discussions.
Organizations that understand the shift now will be better positioned as technologies and regulations continue to evolve.
The NEC’s adoption of the term limited energy helps establish clearer definitions for emerging technologies while maintaining a focus on safe design, installation, and operation.
The next decade is expected to bring continued convergence between power and data systems.
Technologies such as Power over Ethernet (PoE) have already expanded beyond supporting simple network devices. Today, PoE is powering lighting systems, displays, sensors, and a growing range of connected building technologies. At the same time, Class 4 Fault Managed Power systems are extending the ability to deliver higher levels of usable power over greater distances.
According to Krueger, the result is a future where building systems become increasingly interconnected.
“Security, fire, access control, lighting, and building automation increasingly operate as one integrated system rather than as separate silos.”
As these trends continue, the lines between traditional electrical work and information technology are expected to blur. Contractors and project teams that develop expertise across both disciplines will be well positioned to support the next generation of intelligent buildings.
As buildings become more connected, owners and project teams must recognize limited-energy systems for what they truly are: essential infrastructure.
These systems often serve as the backbone that enables building operations, occupant safety, and facility performance.
“Fire alarm, mass notification, access control, and the network backbone are not amenities,” said Krueger. “They are the systems necessary for keeping a building safe and functional.”
Just as owners invest significant attention into electrical service, HVAC systems, and other core building infrastructure, limited-energy systems deserve the same level of planning and long-term investment. The industry’s transition from low voltage to limited energy reflects more than a terminology update. It recognizes how modern building technologies have evolved and provides a framework for safely incorporating the next generation of connected systems.
While the language may be changing, the mission remains the same: delivering reliable, code-compliant systems that keep buildings connected and safe.
