VAR-002-4.1

R1 · Operate in automatic voltage control

What it means. The Generator Operator operates each generator connected to the interconnected transmission system in automatic voltage control mode (with its AVR in service and controlling voltage) or in a different control mode as instructed by the Transmission Operator. The exceptions are a generator exempted by the Transmission Operator, or a Generator Operator that has notified the Transmission Operator either that the generator is in start-up, shutdown or testing under a Real-time communication or a procedure previously provided to the Transmission Operator, or that it is not in the required mode for another reason.

Evidence an auditor expects. Evidence of notification to the Transmission Operator each time a generator was not in the required mode; for start-up, shutdown or testing without a real-time notice, dated evidence that the procedure for placing the unit into automatic voltage control was sent to the Transmission Operator; and, for an exempted generator, evidence of the exemption.

R2 · Maintain the voltage or Reactive Power schedule

What it means. Unless exempted by the Transmission Operator, the Generator Operator maintains the generator voltage or Reactive Power schedule the Transmission Operator provides, within each generating Facility's capabilities, or meets the Transmission Operator's conditions of notification for deviations. With the AVR out of service or absent, it uses an alternative method to control reactive output to meet the schedule. When instructed to modify voltage, it complies or explains why the schedule cannot be met. If it does not monitor voltage at the location named in the schedule, it has a methodology for converting the scheduled voltage to the point it monitors.

Evidence an auditor expects. Operator logs, SCADA data, phone logs and other notifications showing the schedule was maintained or deviations were handled per the Transmission Operator's notification conditions; evidence of the alternative method when the AVR was out of service; evidence of compliance with, or explanation for, instructions to modify voltage; and the voltage conversion methodology where it applies.

R3 · Report AVR and PSS status changes

What it means. The Generator Operator notifies its Transmission Operator of a status change on the AVR, power system stabilizer or alternative voltage controlling device within 30 minutes of the change. No notice is needed if the status is restored within 30 minutes.

Evidence an auditor expects. Evidence of each notification within 30 minutes.

R4 · Report reactive capability changes

What it means. The Generator Operator notifies its Transmission Operator within 30 minutes of becoming aware of a change in reactive capability due to factors other than an R3 status change, unless the capability is restored within those 30 minutes. This reporting does not apply to the individual generating units of dispersed power producing resources identified through Inclusion I4 of the BES definition.

Evidence an auditor expects. Evidence of each notification within 30 minutes of becoming aware of the change.

R5 · Provide transformer data on request

What it means. Within 30 calendar days of a request, the Generator Owner gives its Transmission Operator and Transmission Planner the tap settings, available fixed tap ranges and impedance data for generator step-up and auxiliary transformers with primary voltages equal to or greater than the generator terminal voltage. For dispersed power producing resources identified through Inclusion I4, this applies only to transformers with at least one winding at 100 kV or above.

Evidence an auditor expects. Evidence the tap settings, fixed tap ranges and impedance data were provided to the Transmission Operator and Transmission Planner within 30 calendar days.

R6 · Change step-up transformer taps as specified

What it means. After consulting the Transmission Operator on necessary step-up transformer tap changes, the Generator Owner ensures tap positions are changed to the Transmission Operator's specifications, unless that would violate safety, an equipment rating, a regulatory requirement or a statutory requirement. If it cannot comply, it notifies the Transmission Operator and gives the technical justification.

Evidence an auditor expects. Evidence the taps were changed per the Transmission Operator's documentation, or evidence of the notification when the Generator Owner could not comply.

For inverter-based plants

For dispersed power producing resources identified through BES Inclusion I4, R4 capability-change reporting does not apply to the individual generating units, and R5 covers only transformers with at least one winding at 100 kV or above. Both carve-outs are written for Inclusion I4 BES resources; the standard does not extend them to the non-BES Inverter-Based Resources of Category 2 Generator Operators and Generator Owners, which have been subject to VAR-002-4.1 since May 15, 2026.