# NERC Concludes Formal Ballot on CLO-001/002/003 Standards Mandating Fault Recording on 50+ MW Data Center Transformers

> The North American Electric Reliability Corporation (NERC) has concluded the initial stakeholder voting period on proposed mandatory standards CLO-001-1, CLO-002-1, and CLO-003-1, establishing unprecedented technical requirements for large computational loads connected at 100 kV and above.

- **Publish Date:** 2026-09-18
- **Category:** policy-standards
- **Reading Time:** 5 min
- **Original Source Citation:** [North American Electric Reliability Corporation (NERC) Standards Board](https://www.nerc.com/pa/Stand/Pages/Project-2024-03-computational-loads-standards-ballot-september-2026.aspx)
- **Tags:** NERC, Data Centers, AI Clusters, Reliability Standards, Substations, Fault Recording, Grid Stability
- **Canonical URL:** https://voltformer.com/news/nerc-drafts-mandatory-clo-standards-50mw-data-center-transformers-substations
- **Markdown Source:** https://voltformer.com/news/nerc-drafts-mandatory-clo-standards-50mw-data-center-transformers-substations.md

## Mandatory Digital Fault Recorders on Main Power Transformers

Draft standard CLO-003-1 directly mandates that data centers and crypto-mining facilities with connected loads of 50 MW or greater install triggered point-on-wave digital fault recorders (DFRs) on the high side of their main substation power transformers.

The recording systems must capture transient voltages, phase currents, and frequency deviations at minimum sampling rates of 10 kHz to ensure transparent root-cause event auditing during Bulk-Power System disturbances.

## Enforcing Rigorous Voltage and Frequency Ride-Through Profiles

Standard CLO-002-1 restricts hyperscale facilities from autonomously tripping off the grid during transient voltage dips, preventing sudden multi-gigawatt load shedding that triggered severe regional grid swings in Virginia and Texas during recent heatwaves.

Transmission operators will gain regulatory authority to mandate power-factor correction and synthetic inertia from collocated data center UPS and battery systems.

---
Related: [Power & Energy News Hub](https://voltformer.com/news.md) · [Voltformer Substation & Transformer Catalog](https://voltformer.com/catalog.md)