Notification of revised RC West operating procedures RC0310 and RC0460

RC West has revised the operating procedures referenced below.

RC0310 Mitigating SOL and IROL Exceedances, version 3.1, effective July 9, 2026.

Section 3.5: Added severe low voltage affecting multiple Bulk Electric System (BES) stations as a criterion to assess for potential insecure state.

Section 3.10: Clarified language and indications of potential insecure state for thermal cascading. Most cascading test steps to RC West procedure RC0310C.

Section 3.11: Clarified language and indications of potential insecure state for unsolved contingencies.

Added new Appendix B, detailing the limit hierarchy that RC West uses to determine the limit in force. Updated instances of CAISO Market Operator to Market Operator, minor format and grammar/punctuation edits and removed history prior to five years.

RC0460 Reliability Coordinator Area Restoration Plan, version 4.0, effective July 9, 2026.

Annual Review/Major Update:

Section 2.2: Updated scope of RC restoration plan, to include system disturbance affecting multiple TOP areas potentially due to instability, uncontrolled separation or cascading event.

Section 3.2: Updated RC responsibility and criteria for declaring BES Emergency during a restoration event, and coordination activities to restore BES elements only after assessment and stabilization are complete.

Section 3.3: Updated/added related TOP responsibilities.

Section 3.8: Added new sub-section “Widespread De-energized System Across Multiple Transmission Operator (TOP) Areas.” Added requirement for RC Operator to use the provided job aids for tracking milestones. Added step for RC to provide approval to proceed with restoration only after coordinated assessment and stabilization is completed.

Minor formatting and grammar edits.

The California ISO and RC West operating procedures are available on Operating procedures | California ISO.

Please contact the CAISO/RC West Procedure Control Desk at ProcedureControl@caiso.com with any questions.