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CLO-003-1
Computational Load Protection Coordination & Disturbance Monitoring
CLO-003-1 applies to Computational Load Sites, such as data centers, with a total connected Load of 50 MW or more supplied through electrical equipment connected at 100 kV or above. Each Computational Load Owner records breaker position and runs a process that keeps Protection System settings coordinated with the other owners of electrically joined equipment. Whoever owns the main power transformer supplying the site, whether the Computational Load Owner, a Transmission Owner, a Distribution Provider or a Generator Owner, keeps fault and dynamic disturbance recordings. Each entity keeps its recorded data time-synchronized and provides it on request. The standard passed final ballot on October 14, 2026 and was adopted by the NERC Board of Trustees on October 26, 2026; it awaits filing with FERC and FERC approval and is not in force.
Who it applies to
- Computational Load Owners, the entities that own and maintain a Computational Load Site. The owner always carries R1, R9 and R10, plus R6 to R8 for its R1 sequence of events recording data. If it owns the main power transformer(s) supplying the site, it also carries R2 to R5, plus R6 to R8 for that fault and dynamic disturbance recording data.
- Covered sites: Computational Load Sites with a total connected Load greater than or equal to 50 MW that are supplied through electrical equipment connected at a voltage level greater than or equal to 100 kV from one or more points of connection. A Computational Load Site is one or more buildings, structures or installations at a single location that primarily contains information technology infrastructure used for creating, executing and delivering software applications and services, artificial intelligence training, deployment and delivery, cryptocurrency mining, or other computational activities at a data center, and that is supplied through electrical equipment connected to the Bulk-Power System.
- Generator Owners that own the main power transformer(s) supplying a Computational Load Site, such as a co-located data center. That Generator Owner carries the fault recording and dynamic disturbance recording requirements (R2 to R4) and the sampling, time synchronization, data delivery and failure restoration requirements for that data (R5 to R8). R1, R9 and R10 fall on the Computational Load Owner, whose R9 process must respond to and communicate with a Generator Owner whose equipment is electrically joined at the site.
- Transmission Owners and Distribution Providers that own the main power transformer(s) supplying a Computational Load Site (R2 to R8).
Key dates
- October 8, 2026: the NERC Board of Trustees approved proposed Rules of Procedure revisions that would establish Computational Load Owner and Computational Load Operator as functional entity types once FERC approves them, with registry criteria covering sites with a total connected Load of 50 MW or more supplied through electrical equipment connected at 100 kV or above. NERC had not filed them with FERC as of October 20, 2026. The implementation plan expects Computational Load Owners to be registered beginning in 2027.
- October 14, 2026: CLO-003-1 and its implementation plan passed final ballot.
- October 26, 2026: the NERC Board of Trustees adopted CLO-003-1, together with CLO-001-1, CLO-002-1 and the conforming FAC revisions, as reported by the American Public Power Association. NERC files them with FERC by December 31, 2026. CLO-003-1 is not in force; its effective date follows FERC approval and the implementation plan.
- December 31, 2026: deadline for NERC to file the standards with FERC, set by FERC's July 16, 2026 order (196 FERC ¶ 61,031, Docket No. RD26-7-000).
- Effective date (not yet set): where governmental approval is required, as with FERC in the United States, CLO-003-1 and the definitions of Computational Load Site and Computational Load Owner become effective on the first day of the first calendar quarter after the effective date of the order approving it, or as that authority otherwise provides. No approval order exists yet, so every date below is counted from an effective date that is still unknown.
- 9 months after the effective date: R9 and R10 (protection settings coordination process).
- Sites in service on or before the effective date: R1 to R8 apply 36 months after the effective date.
- Sites in service after the effective date: R1 to R8 apply 15 months after the effective date or on the in-service date, whichever is later.
- Worked example: If CLO-003-1 became effective April 1, 2027, a site already in service on that date would comply with R1 to R8 by April 1, 2030; a site entering service after April 1, 2027 but on or before July 1, 2028 would comply by July 1, 2028; and a site entering service after July 1, 2028 would comply on its in-service date. April 1, 2027 is the implementation plan's illustration, not a scheduled date.
- Extension request (R1 to R8): an entity with one or more applicable sites in service no later than 12 months after the effective date may ask its Compliance Enforcement Authority for more time if circumstances beyond its control prevent installing Disturbance Monitoring Equipment, such as supply chain delays, inability to secure scheduled outages, or other exceptional circumstances. The request identifies the sites, gives a plan and timetable, explains the circumstances, and is due no later than 3 months before the compliance date in question.
Source
NERC Project 2026-02 (final ballot draft, October 2026)October 29, 2026
Requirements
What each requirement asks for, in plain English.
R1 · Sequence of events recording (SER)
What it means. Each Computational Load Owner has sequence of events recording data at its sites for circuit breaker position (open/close) for the breakers associated with equipment it owns, including buses and, as applicable, the main power transformer(s), on-site generation, and shunt static and dynamic reactive devices.
Evidence an auditor expects. Actual data recordings; documents describing the device interconnections and configurations, which may be a single design standard representative of common installations; or station or equipment drawings.
R2 · Fault recording (FR) at the main power transformer
What it means. Whichever Computational Load Owner, Transmission Owner, Distribution Provider or Generator Owner owns the main power transformer(s) supplying the site has triggered fault recording data on the high side of the main power transformer(s) or the common point(s) of connection, enough to determine phase-to-neutral voltage for each phase, each phase current and the residual or neutral current, and three-phase Real and Reactive Power. The main power transformer is the power transformer and associated equipment that steps the site's voltage down from its nominal transmission or interconnecting system voltage.
Evidence an auditor expects. Actual data recordings or derivations; documents describing the device specifications and configurations, which may be a single design standard; or station or equipment drawings.
R3 · Fault recording specifications
What it means. The owner of the main power transformer(s) makes sure its R2 fault records include at least two cycles before the trigger and at least 2.0 seconds in total for the same trigger point, in one record or several; record at least 64 samples per cycle; and trigger on at least neutral (residual) overcurrent, AC phase overvoltage and undervoltage, and overfrequency and underfrequency.
Evidence an auditor expects. Actual data recordings or derivations, or documents describing the device specification and its configuration or settings.
R4 · Continuous dynamic disturbance recording (DDR)
What it means. The owner of the main power transformer(s) has continuous dynamic disturbance recording and storage on the high side of the main power transformer(s) or the common point(s) of connection, enough to determine phase-to-neutral voltage for each phase, each phase current and the residual or neutral current, three-phase Real and Reactive Power flows for all circuits where current is measured, and the frequency of any one of the recorded voltages.
Evidence an auditor expects. Actual data recordings or derivations; documents describing the device specifications and configurations, which may be a single design standard; or station drawings.
R5 · DDR sampling and recording rates
What it means. The entity responsible for the R4 data samples inputs at 960 samples per second or more and records electrical quantities at least 60 times per second.
Evidence an auditor expects. Documents describing the device specification, configuration or settings, or actual data recordings for the recording rate.
R6 · Time synchronization
What it means. The entity responsible for the SER, FR or DDR data synchronizes it to Coordinated Universal Time (UTC), with or without a local time offset, with device clocks within 1 millisecond of UTC.
Evidence an auditor expects. Documents describing the device specification, configuration or setting; time synchronization indication or status; or station drawings.
R7 · Keep and provide recorded data
What it means. The entity responsible for the data provides all requested SER, FR and DDR data to its Transmission Planner, Planning Coordinator, Transmission Operator, Balancing Authority, Reliability Coordinator, Regional Entity or NERC. Data stays retrievable for 20 calendar days, counting the day it was recorded, and is provided within 15 calendar days of a request unless the requestor grants an extension. SER data goes in ASCII CSV format following the standard's Attachment 1; FR and DDR data in CSV with appropriate headers or COMTRADE (IEEE C37.111, 1999 or later); file names follow COMNAME (IEEE C37.232-2011 or later).
Evidence an auditor expects. Actual data recordings; dated transmittals to the requesting entity with formatted records; or documents describing data storage capability, device specification, configuration or settings.
R8 · Restore failed recording
What it means. On discovering a failure of SER, FR or DDR recording capability, the responsible entity restores it within 90 calendar days, or submits a Corrective Action Plan (CAP) to the Regional Entity within 90 calendar days and then carries it out on the CAP timeline.
Evidence an auditor expects. Dated reports of the discovery of a failure, documentation of the date recording was restored, SCADA records, or dated CAP transmittals to the Regional Entity with evidence the CAP was implemented.
R9 · Protection System settings coordination process
What it means. Each Computational Load Owner establishes a process for developing new and revised Protection System settings at its sites so that Protection Systems operate in the intended sequence during Faults. Where settings are applied on a site that electrically joins equipment owned by separate Transmission Owners, Generator Owners or Distribution Providers, the process provides for responding to any owner that proposed settings by identifying coordination issues or affirming that none were found; verifying that identified issues are addressed before implementation; and communicating with the other owners about settings revised because of unforeseen circumstances during implementation or commissioning, Misoperation investigations, maintenance, or emergency replacements after a Protection System component failure.
Evidence an auditor expects. Dated electronic or hard copy documentation showing the process was established.
R10 · Use the process
What it means. Each Computational Load Owner uses its R9 process to develop new and revised Protection System settings for its sites.
Evidence an auditor expects. Dated electronic or hard copy documentation showing the process was used.
For data-center owners
A Computational Load Owner always carries R1, R9 and R10. It carries R2 to R4 only if it owns the main power transformer(s) supplying the site. R5 to R8 apply to whoever is responsible for the recorded data, so R6 to R8 cover the owner's R1 SER data in every case. Evidence for R1 to R8 is kept for three calendar years; evidence for R9 and R10 is kept from the last audit onward.
For generation owners with a co-located data center
A Generator Owner that owns the main power transformer(s) supplying a Computational Load Site carries R2 to R4 and, for that data, R5 to R8. Its compliance date for R2 to R8 depends on the site's in-service date, as set out in the key dates. Where the site's settings electrically join equipment the Generator Owner owns, the Computational Load Owner's R9 process responds to the Generator Owner's proposed settings and communicates revised settings to it.
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