March 28, 2024
Forward to Operating Department
Notification of revised ISO operating procedures 4510A and 8110B

The California ISO has revised the operating procedures referenced below.


4510A Load Shed Calculation Guideline - Public Attachment, version 13.4, effective March 28, 2024.

Annual review: Updated percentage numbers based on 2023 peak load data.


8110B Interchange Scheduling Limits, version 11.3, effective Mar. 28, 2024.

Retired – This procedure attachment is no longer required with update of 8110, which now includes the following reference documents on the ISO website. Intertie Constraint and Branch Group Information Full Network Model Reference Document, which contains the drawing utilized as procedure attachment 8110B. This document is located on the CAISO Public website at Network and Resource Modeling webpage, under the Network Modeling heading and Intertie constraint and branch group information subheading. Please use the latest version of the document for your reference.


The California ISO’s operating procedures are available on the Operating Procedures webpage.


Please contact the CAISO/RC West Procedure Control Desk at with any questions.

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