PJM Will File Its Own Data Center Ride-Through Rule in November, Before NERC Sets Thresholds

PJM introduced a proposal on September 8, 2026. It would require large data centers and crypto-mining sites to stay connected during transmission faults. These Large Load facilities would ride through voltage and frequency excursions beyond acceptable operating limits, where today many simply trip offline. PJM plans to file the proposal at the Federal Energy Regulatory Commission in November 2026. The trigger was a July 22 event in northern Virginia. About 3,800 MW of data center load disconnected there without warning.

A fault on a 230-kV line in Dominion Energy’s zone started that event. It was the largest load loss of its kind in PJM history. PJM brought the proposal to its Planning Committee and scheduled a special session on Large Load ride-through for September 15.

Before and After

Today the PJM tariff puts no ride-through duty on these customers. FERC said so directly in an order that PJM dates to June 18, 2026. That order found the tariff does not specify ramp rate or ride-through requirements. A large data center that drops its whole load during a normally cleared fault breaks no PJM rule today. Under the proposal, staying connected becomes an interconnection requirement, settled before the load energizes.

Enforcement Reality

PJM writes this rule for its own footprint, and FERC must accept the November filing before it binds anyone. The national duty runs on a slower clock. FERC ordered NERC on July 16, 2026, in Docket RD26-7-000, to file initial mandatory standards for computational loads by December 31, 2026. NERC must also submit a work plan for further standards by March 1, 2027. Minimum voltage and frequency ride-through thresholds sit in that later work, which trade reporting places in 2027.

FERC set no size threshold, no registration category and no compliance obligations in the July order, leaving all three to NERC. The number that decides which data centers are covered does not yet exist nationally. PJM moves to set its own in November.

Why It Matters

Sign a PJM interconnection agreement for a large computational load and assume a ride-through duty lands before the facility energizes. PJM staff argue the requirements belong in place before the load reaches the system. Design reviews that treat protective tripping as free deserve a second look now, not after the FERC order.

The gap is the risk. PJM aims at November 2026 while NERC’s thresholds arrive in 2027. A developer connecting in between meets an RTO rule with no matching national standard behind it. MISO, ERCOT, Dominion and American Electric Power have each advanced their own versions. A multi-region operator will answer to several ride-through specifications rather than one.

The precedent predates this summer. A NERC review examined a July 10, 2024 event, where a 230 kV fault triggered six successive faults. Roughly 1,500 MW of data-center load went off almost at once. The July 22, 2026 event was more than twice that size.

Critical Perspective

A proposal introduced at a committee is not a rule. PJM has said only that it plans to file in November, and FERC sets its own clock after that. The July 22 event happened in Dominion’s zone in northern Virginia, so the operators whose load tripped are already connected. Nothing here reaches them until PJM says whether the rule covers existing facilities or only new interconnections.

The thresholds are the missing part. FERC set no size threshold, no registration category and no compliance obligations in its July order. NERC’s own voltage and frequency numbers do not arrive until next year. A ride-through duty with no voltage floor, no time window and no penalty is a direction, not a specification. Engineers cannot set a protective relay against it.

There is also a reason data centers trip. Their protective schemes guard hardware. Some designs also hand load to on-site generation or a UPS. PJM’s materials describe what the grid needs. They do not resolve who pays when riding through a fault damages equipment the operator was protecting.

Read the multi-RTO pattern with care. MISO, ERCOT, Dominion and American Electric Power agree on the problem. They do not yet agree on the numbers. Four rules with four thresholds is a worse outcome for a national operator than one slower standard.

Sources

• PJM Inside Lines: Reliability Standards to Manage Large Load Disconnection Events Proposed by PJM (September 10, 2026)
• Utility Dive: PJM eyes data center, crypto reliability requirements after 3.8 GW of load trips offline (August 12, 2026)
• POWER Magazine: FERC Orders Mandatory NERC Reliability Standards for Data Center and Other Computational Loads (July 16, 2026)

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