Digital Electricity on Site: How Installs Change with FMP

Fault-Managed Power (FMP) under NEC Article 726 rewrites the rules for distributing high-voltage DC across campuses and data centers—here is what installers and facility engineers need to know before the first cable hits the tray.
By Todd Taskerud, AWS CCP, RCDD/NTS/OSP/WD, LEED GA
5 min read
Digital Electricity on Site: How Installs Change with FMP

A New Circuit Class Changes Everything

For decades, power and data infrastructure lived in separate worlds, each governed by its own code regime, its own conduit requirements, and its own crew. Fault-Managed Power (FMP)—sometimes called Digital Electricity (DE, a VoltServer trademark) or Packet Energy Transfer—collapses that boundary in a way that is both exciting and, frankly, a little disorienting for teams trained on conventional wiring practice.

The 2023 National Electrical Code introduced Article 726 to formalize FMP as a distinct circuit class, separate from the familiar Class 1, 2, and 3 circuits covered under Article 725. Understanding what Article 726 permits—and what it still demands—is the starting point for any FMP installation conversation.

What Makes FMP "Touch-Safe"?

The core premise of FMP is that energy is delivered in monitored packets. The transmitting equipment continuously validates each packet; if a fault condition is detected—an open conductor, an unintended contact, a downstream anomaly—the system shuts off energy flow in milliseconds. The result is a conductor that may carry voltages well above conventional low-voltage thresholds yet remains touch-safe under fault conditions.

Equipment used in FMP systems must be listed to UL 1400-1, and the cable itself must be listed to UL 1400-2. These listing requirements are the safety foundation that Article 726 rests on; substituting unlisted components undermines the entire touch-safety argument and puts an installation out of code compliance immediately.

How NEC Article 726 Relaxes Installation Requirements

The practical installation benefit that draws so much interest is the wiring-method flexibility. Because the fault-managed nature of the circuit is engineered into the equipment and verified by listing, Article 726 allows FMP cable to be installed without conduit in most cases—a significant departure from conventional power wiring methods governed elsewhere in NEC/NFPA 70 Chapter 3.

Key installation considerations under Article 726 include:

  • Cable type and listing: Only UL 1400-2 listed cable qualifies. Installers cannot simply pull existing Category cabling and energize it at FMP voltage levels without the proper listing.
  • Plenum and riser ratings: Even with relaxed mechanical protection requirements, the cable's fire-rating must match the space. Plenum spaces still require CMP-rated cable; risers require CMR—requirements that flow from NEC/NFPA 70 regardless of circuit class.
  • Pathways and spaces: ANSI/TIA-569 governs pathways and spaces for telecommunications infrastructure, and its physical separation and bend-radius guidance remains a useful baseline for routing FMP cable through the same facilities where structured cabling lives.
  • Bonding and grounding: FMP transmitters and receivers introduce new grounding topology questions. ANSI/TIA-607 governs bonding and grounding for telecommunications systems, including the Telecommunications Main Grounding Busbar (TMGB) and Telecommunications Grounding Busbar (TGB) hierarchy. Coordinating FMP equipment grounding with the existing TN-S grounding scheme documented under TIA-607 avoids ground-loop problems and simplifies inspections.
  • Labeling: ANSI/TIA-606 administration and labeling practices apply to any cable plant sharing pathways with FMP runs. Clear, standardized labeling is critical when a single tray may carry both UL 1400-2 FMP cable and conventional balanced twisted-pair cabling governed by ANSI/TIA-568.2-D.

FMP in the Data Center Context

Data centers are a primary target application for FMP deployment, particularly for distributing power to edge nodes, remote radio heads, IoT endpoints, and anywhere that the cost of conventional branch-circuit conduit work is prohibitive.

In a data center governed by ANSI/TIA-942, power distribution architecture is tightly coupled to redundancy ratings. FMP does not replace the upstream utility and UPS infrastructure that defines a facility's Tier classification under the Uptime Institute framework; it operates downstream of that infrastructure, extending reach without adding the conduit burden of conventional wiring. Thermal management still follows ASHRAE TC 9.9 guidelines—a recommended IT inlet range of approximately 18–27°C applies to the IT equipment receiving FMP-delivered power just as it does to conventionally powered equipment. PUE calculations (total facility power divided by IT power) should account for FMP transmitter losses, which vary by product and load; consult manufacturer datasheets for efficiency curves.

Heather Technologies partners with DCPacket, whose Titan Platform brings FMP to data-center environments, and with VoltServer, the originator of the Digital Electricity architecture. VoltServer's DE system is representative of FMP technology capable of delivering power over data-type cable at distances that are impractical for conventional low-voltage DC—[FLAG: VoltServer DE up to ~450 V / ~2,000 W per channel over ~2 km—verify against current VoltServer product documentation before specifying]. DCPacket and VoltServer announced a partnership in December 2025 to bring these capabilities to enterprise data-center deployments.

Where Structured Cabling Still Governs

FMP changes power distribution, not data transmission. The optical-fiber cabling plant—governed by ANSI/TIA-568.3-D for fiber types (OM3/OM4/OM5 multimode; OS1/OS2 singlemode), connectors (LC, SC, MPO/MTP), and polish specifications (UPC vs. APC)—remains entirely separate from the FMP cable plant and unchanged in its installation requirements. Similarly, balanced twisted-pair cabling governed by ANSI/TIA-568.2-D (Cat 6A for most new data-center horizontal runs; Cat 8 for short-reach 25/40GBASE-T to approximately 30 meters) coexists with FMP cable in the same facility but must be routed and managed according to its own standard.

Where PoE under IEEE 802.3bt (Type 3 up to 60 W at the PSE; Type 4 up to 90 W at the PSE) is already delivering power over data cabling, FMP represents a complementary—not competing—technology. PoE excels at powering endpoint devices over short horizontal runs; FMP addresses longer distances and higher per-channel power budgets that exceed what 802.3bt can economically deliver.

Preparing Your Team for Article 726 Work

The most common mistake we see in early FMP project planning is treating Article 726 installs as either purely electrical work or purely low-voltage work. They are neither in isolation. A successful deployment requires:

  • Electrical contractors familiar with NEC Article 726 and UL 1400-1/-2 listing requirements
  • Low-voltage cabling teams coordinating pathway use under ANSI/TIA-569 and labeling under ANSI/TIA-606
  • Facility engineers aligning FMP grounding with the ANSI/TIA-607 bonding infrastructure already in place
  • Data-center operators integrating FMP power budgets into ANSI/TIA-942 power and cooling capacity planning

As FMP adoption accelerates—driven by edge computing, distributed antenna systems, and the ongoing push to reduce conduit labor costs—the installers who invest in understanding Article 726 now will be well ahead of the curve. Heather Technologies is positioned to support that transition with the right products, the right partners, and the application engineering to bridge the gap between the code page and the cable tray.

 

About the author — Todd Taskerud, AWS CCP, RCDD/NTS/OSP/WD, LEED GA, is a BICSI-credentialed communications distribution designer at Heather Technologies, specializing in fiber, copper, and data-center network infrastructure.