by Michal Hofkin, Lead Regulatory Engineer, UL Solutions
The modernization of homes and businesses in the 21st century is increasingly driven by electrification and smart control systems. The 2026 National Electrical Code® (NEC®) distinguishes between energy management functionality and circuit safety protection when Energy Management Systems (EMS) are implemented. A Power Control System (PCS) is essential to this evolution. It can enable safety and flexibility when integrating new technologies, electrification, and localized generation – while making the most of existing infrastructure in homes, businesses, and other installation sites.
The 2026 edition of NFPA 70®, the National Electrical Code® (NEC®), was issued by the National Fire Protection Association (NFPA®) Standards Council on August 20, 2025, with an effective date of September 9, 2025. There were many significant changes made to the newest NEC®. One of these changes was the relocation of Article 750 Energy Management Systems to Chapter 1 in Article 130. Article 130 was expanded to include a new Part II, which contains the requirements for Energy Management Systems used as Power Control Systems. A PCS is an EMS that provides controls required to prevent the overloading of conductors and equipment. This separation distinguishes the requirements for traditional energy management (Part I) from those corresponding to power control (Part II).
Section 130.2 requires that EMS be listed (Certified). If the EMS provides overload control, it must be Certified (Listed) as a PCS. A new Informational Note No. 1 clarifies that the evaluation of an EMS differs from that of an EMS with PCS functionality.
The Outline of Investigation for Power Control Systems, UL 3141, covers Power Control Systems (PCS) supplied by one or more power sources, which may include the utility grid. PCS can be utilized to control sources, loads, or combinations of both. The UL 3141 Standard for a PCS includes requirements for evaluating the critical controls for overload mitigation to avoid fire and electric shock.
These are the PCS functions that can be evaluated for overload control:
- Busbar overload control
- Feeder conductor overload control
- Branch conductor overload control
- Single-source overload control
Part II of Article 130 requires that the PCS monitor and control the circuits connected to it to prevent overloads of conductors, power sources, and distribution equipment. Upon detection of a PCS failure or malfunction, the system shall initiate a transition to a predefined controlled state in accordance with the functional safety requirements of UL 3141 to mitigate the risk of an electrical overload., If a malfunction occurs when the PCS is required to enter a controlled state, it is not permitted to cause the overcurrent protective device (OCPD) of non-PCS-controlled circuits to open. In the case of PCS-controlled OCPDs (e.g., shunt trip breakers), PCS-controlled operation (e.g., opening) of a PCS-controlled device is allowed as a means to enter a controlled state.
PCS settings must allow adjustment in amperes for each PCS-controlled conductor, source, or load, and these settings are considered continuous loads. Adjustable overload control settings can only be accessed by qualified service technicians using methods specified by the PCS listing. Control settings may also be used in load and source calculations, as referenced in other code sections.
Equipment or circuits supplying branch circuits, feeders, or services must be clearly marked with PCS control settings, identification of managed loads and sources, and, in non-dwelling occupancies, the date of calculation and the qualified person’s identification. Markings must include wording such as “Circuits within this equipment are controlled by a power control system. The control settings shall only be changed by a qualified person,” and comply with the visibility requirements in 110.21(B). Documentation must list all monitoring and control functions, equipment, and settings, and indicate whether it is a multisource or single-source PCS. Additionally, all PCSs are required to provide single-line diagrams for each PCS functionality included. If PCS control equipment is not within sight of the OCPDs for controlled circuits, a directory identifying controlled devices and circuits must be posted on the enclosure of the control device, disconnect, or OCPD.
A multisource PCS may be used to limit current and manage loading on busbars and conductors connected to the output of one or more linked interconnected electric power production sources or energy storage sources in combination with the utility supply.
When a PCS is used to manage the load of Electric Vehicle Supply Equipment (EVSE), the maximum load on a service, feeder, or branch circuit shall be limited to the amount allowed by the PCS. If one or more pieces of equipment include integrated load management controls, the system must be marked to indicate that such control is provided.
UL Certifies (Lists) Energy Management Systems under the product category Energy Management Equipment (PAZX) for compliance with the Standard for Safety for Energy Management Equipment, UL 916, or the Standard for Safety for Automatic Electrical Controls – Part 1: General Requirements, UL 60730-1. UL Certifies (Lists) Power Control Systems under the product category Power Control Systems PCS (QIJE) for compliance with the Outline of Investigation for Power Control Systems, UL 3141. The UL guide information and Certifications (Listings) can be viewed on UL Product iQ at UL.com/piq; enter PAZX or QIJE in the search field.
Power control systems (PCSs) represent cutting-edge technology for increasing the electrification of homes and buildings by making the most of the existing infrastructure. The UL 3141 Standard was developed to establish safety requirements to support the integration of a PCS and associated control systems in both new and existing installations.
This article contains excerpts and paraphrasing from the 2026 edition of NFPA 70® National Electrical Code®.
Contact Us
Phone: +1.800.595.9844
Email: ULRegulatoryServices@ul.com
Power Control Systems for Distributed Energy Resource Systems
Certification to UL 3141, the Outline of Investigation for Power Control Systems (PCS), helps meet compliance and safety standards and drive innovation across residential and commercial applications.