"Low Voltage" Is No Longer the Safety Standard. The 2023 NEC Just Changed Everything.
The 2023 National Electrical Code (NEC) made a terminology change that the low voltage and structured cabling industry cannot afford to ignore: it replaced “Low Voltage” with “Limited Energy”, and the distinction matters far more than most people realize.
Voltage alone doesn’t define danger. The 2023 NEC finally catches up with that reality.
For decades, our industry used “low voltage” as shorthand for low risk. If the voltage was below a certain threshold, the assumption was that the circuit was inherently safe. But that assumption was always incomplete, and as our electrical and digital infrastructure grows more complex, it’s become genuinely dangerous. This post breaks down what the change means, why it matters for your projects right now, and how Net Scaling Solutions is already designing systems that align with where the NEC is heading.
The Problem With "Low Voltage" as a Safety Concept
Low voltage has always been a blunt instrument as a safety category. A 24V circuit sounds harmless, until you factor in fault current. Under the right (or wrong) conditions, a 24V circuit with sufficient fault current can cause serious electrical burns, ignite a fire, or damage sensitive equipment. Voltage is only one variable in the energy equation.
The formula hasn’t changed: energy = voltage × current × time. A circuit at low voltage but high current, sustained for even a brief duration, carries real destructive potential. The old “low voltage = low risk” mental model glossed over this, and the 2023 NEC corrects it.
A 24V PoE++ circuit delivering 90W is not the same risk profile as a 24V doorbell transformer. The 2023 NEC acknowledges that difference explicitly.
The shift to “Limited Energy” reframes the question from “what is the voltage?” to “what is the inherent energy capacity of the source?” That’s a fundamentally more accurate way to assess risk, and it brings the electrical code into alignment with how modern systems actually behave.
What the 2023 NEC Change Actually Means
It's About Source Energy Capacity, Not Voltage Reading
Under the new framework, a circuit is evaluated by whether its power source is inherently limited in the energy it can deliver, not simply by its nominal voltage. This means classification depends on the supply characteristics, including how much current it can source under fault conditions, not just what voltage it operates at.
For structured cabling and low voltage professionals, this has direct implications for how you classify, design, and document systems, particularly when those systems include high power PoE, building automation, or IoT-connected devices.
Technologies Driving the Change
The 2023 NEC didn’t make this change arbitrarily. Three emerging technology categories made the update necessary:
- High-Power PoE (PoE++): Â IEEE 802.3bt Type 3 and Type 4 deliver up to 90W per port. That’s a fundamentally different energy profile from a basic IP camera. PoE++ circuits require a more rigorous energy-based assessment than legacy low voltage classifications provided.
- IoT and Smart Building Systems: Â Modern buildings integrate hundreds of interconnected sensors, controllers, and edge devices, many operating on circuits that mix power and data. As these systems grow more capable, their energy capacity grows with them.
- Next-Generation Building Automation:Â HVAC controls, access control systems, lighting management, and energy monitoring have all increased in complexity and power draw. The voltage centric framework couldn’t adequately address these hybrid systems.
The NEC’s response is a classification system that reflects actual energy risk, creating clearer, more consistent guidance for designers, inspectors, and installers working across all these technology types.
Why This Matters for Structured Cabling and Low Voltage Professionals
Design and Documentation
If your project specifications still reference “low voltage” as a safety classification, they may already be out of step with the 2023 NEC. As adoption accelerates, most jurisdictions are on a 3–6 year adoption cycle; specs, drawings, and submittals will need to reflect the “Limited Energy” framework.
This is especially relevant for PoE infrastructure design. When specifying cabling for a high-power PoE deployment, the energy capacity of the switch or injector is now a classification factor, not just a performance spec. That changes how you document the installation and how it gets inspected.
Inspections and Code Compliance
Inspectors working under the 2023 NEC will be applying the Limited Energy framework, which means the way installations are categorized, labeled, and presented for inspection is shifting. Professionals who understand the new terminology early are better positioned to move projects through inspection without delays or correction notices.
Conversations With Clients and Engineers
How Net Scaling Solutions Applies This in Practice
At Net Scaling Solutions, we design and install structured cabling, access control, and surveillance systems for commercial clients across Maryland and the Mid-Atlantic region. The shift to Limited Energy isn’t an abstract regulatory concern for us, it shows up directly in how we specify PoE infrastructure, how we document installations, and how we advise clients on system design.
When we design a structured cabling system that includes high-power PoE for IP cameras, wireless access points, or smart building controllers, we evaluate the energy capacity of the sourcing equipment, not just the cable rating. That means selecting the right cable category, ensuring appropriate separation and routing, and documenting the installation in a way that’s inspection-ready under the current code.
It also means we stay current. The 2023 NEC is the active standard our team designs to, and we track adoption timelines in our jurisdictions so our clients are never caught off guard by a code compliance issue
Frequently Asked Questions
“Low Voltage” classified circuits based on their nominal voltage reading. “Limited Energy” classifies circuits based on the inherent energy capacity of the power source — specifically, whether the source is limited in the current it can deliver under fault conditions. This is a more accurate way to assess actual electrical risk, particularly for modern high-power circuits like PoE++ that operate at low voltages but deliver significant wattage.
Existing installations are typically grandfathered under the code in effect at the time of installation. However, any modifications, expansions, or new installations in jurisdictions that have adopted the 2023 NEC should comply with the Limited Energy framework. Check with your local Authority Having Jurisdiction (AHJ) for specifics on adoption status in your area.
High-power PoE (PoE++, delivering up to 90W) falls under more rigorous classification under the Limited Energy framework than it did under legacy low voltage rules. This affects cable selection, routing requirements, separation from other systems, and documentation. Designers specifying PoE infrastructure should review their standard details against the 2023 NEC to ensure compliance.
Adoption timelines vary by state and locality, most jurisdictions adopt each edition within 3–6 years of publication. Maryland and many Mid-Atlantic states are actively working through the 2023 adoption cycle. Check with your local AHJ or state electrical board for the current adopted edition in your jurisdiction.
The Bottom Line
The 2023 NEC’s shift from “Low Voltage” to “Limited Energy” isn’t bureaucratic wordsmithing. It’s the code catching up with the reality of how modern electrical and digital systems actually work, and it has real implications for how professionals design, install, document, and inspect those systems.
The old assumption that low voltage equals low risk was always an oversimplification. As PoE power levels increase, IoT systems multiply, and building automation becomes more sophisticated, that oversimplification becomes a liability. The Limited Energy framework gives the industry a more precise, technology appropriate foundation to build on.
The professionals who understand this change early, and apply it consistently, will be better equipped to deliver safer, more compliant, and more future-proof installations for their clients.
Related: Learn more about our structured cabling services and how we design for long term code compliance.
