Message Definitions
Message TypeDefinitionPriority
Cold Weather AlertThe purpose of the Cold Weather Alert is to prepare personnel and facilities for expected extreme cold weather conditions. As a general guide, PJM can initiate a Cold Weather Alert across the RTO or on a Control Zone basis when the forecasted/actual weather conditions approach 10 degrees Fahrenheit or below. PJM can initiate a Cold Weather Alert at higher temperatures if PJM anticipates increased winds or if PJM projects a portion of gas fired capacity is unable to obtain spot market gas during load pick-up periods. PJM will initiate the Cold Weather Alert for the appropriate region(s) in advance of the operating day based on historical experience, information supplied by the pipelines and/or information supplied from the generator owners. Alert
Conservative OperationsConservative Operations can be declared when the PJM RTO (or a portion of the RTO) is undergoing, or has the potential to face, adverse impacts from weather, environmental, physical or cyber security events and requires enhanced RTO reliability efforts. The declaration of Conservative Operations may include additional actions, including recalling/cancelling non-critical maintenance outages, reductions in transfers into, across or through the PJM RTO, increased reserves, and/or additional requests placed upon PJM member TOs and GOs. Alert
Curtailment of Non-Essential Building LoadPAHThe purpose of the Curtailment of Non-Essential Building Load is to provide additional load relief, to be expedited prior to, but no later than the same time as a voltage reduction. PJM and Member facilities may be implemented at the same time. Action
Deploy All Resources ActionPAHFor emergency events that evolve over time, PJM will dispatch generation and Load Management resources via the normal mechanisms of SCED, DR Hub and direct phone calls. However, for emergency events that develop rapidly and without prior warning, PJM may need to dispatch all resources in a large area very quickly. The purpose of the Deploy All Resources Action, during such emergency conditions, is to instruct PJM Members that all generation resources are needed online immediately and that all Load Management resources dispatched need to reduce load immediately. This step is issued when unplanned events such as the loss of a transmission or generating facility(s) have resulted in reliable operations being jeopardized such that a Voltage Reduction Action or a Manual Load Dump Action may be required. Action
Emergency Energy RequestThis is a request by PJM for emergency purchases of energy. PJM will select which offers are accepted based on price and expected duration of the need. This request is typically issued at the Max Emergency Generation emergency procedure step. The Emergency Energy Bid Form can be found on the webpage for Emergency Conditions. Informational
Emergency Load Mgmt Reduction ActionPAHThe purpose of the Load Management Reduction Action is to provide additional load relief by using PJM controllable load management programs. Action
Emergency Voluntary Energy Only Demand ResponsePAHThe purpose is to request end-use customers registered in PJM's Emergency Voluntary Energy Only Demand Response to reduce load. These reductions are voluntary. Action
Geomagnetic Disturbance ActionGeomagnetically-induced currents (GIC) flowing through power system equipment and facilities caused by a geomagnetic disturbance (GMD) are resulting in major increases in system reactive requirements as well as potential equipment damage and disruption of interconnected system operation. The PJM dispatcher will operate the system to more conservative geomagnetic disturbance transfer limits as indicated in PJM Manual M-13 Section 3.7. Action
Geomagnetic Disturbance WarningGeomagnetically-induced currents (GIC) flowing through power system equipment and facilities caused by a geomagnetic disturbance (GMD) may result in major increases in system reactive requirements, equipment damage and disruption of interconnected system operation. The PJM dispatcher notifies members (Generation and Transmission) via the PJM All-Call of GMD warnings of level K-5 and above that are issued by the National Oceanic and Atmospheric Administration (NOAA). Warning
High System VoltageAll companies shall take the following actions on the Bulk Electric System: 1. All switchable capacitors are out of service. 2. All reactors are in service. 3. Transmission Owners are requested to review and adjust LTC settings as appropriate. All LTC (230 kV and above) and voltage schedule adjustments shall be coordinated with PJM Dispatch. 4. All SVCs are absorbing reactive power. 5. Generation Owners shall operate generators at the lower bandwidth of their voltage schedule when possible. 6. Generation Owners shall communicate with PJM and the Transmission Owner restrictions to their generator's ability to absorb MVARs if that capability varies from the existing "D" curve. Target: Distribution Companies/Transmission Owners/Generation Owners Action
HLV ActionA Heavy Load Voltage (HLV) Schedule Action is issued to members (Generation and Transmission) at peak load periods via the ALL-CALL system to request maximum support of voltages on the bulk power system and increase reactive reserves on the 500kv system. Action
HLV WarningA Heavy Load Voltage (HLV) Schedule Warning is issued to members via the ALL-CALL system (Generation and Transmission) to request members to prepare for maximum support of voltages on the bulk power system. Warning
Hot Weather AlertThe purpose of the Hot Weather Alert is to prepare personnel and facilities for expected extreme warm weather conditions. As a general guide, PJM can initiate a Hot Weather Alert across the RTO or on a Control Zone basis when the forecasted/actual weather conditions approach 90 degrees Fahrenheit (93F within the DOM/Southern Zone) or above . PJM can initiate a Hot Weather Alert at lower temperatures if PJM anticipates increased humidity or if PJM projects a portion of gas fired capacity is unable to obtain spot market gas during load pick-up periods. PJM will initiate the Hot Weather Alert for the appropriate region(s) in advance of the operating day based on historical experience, information supplied by the pipelines and/or information supplied from the generator owners. Alert
IROL - Information OnlyCertain system conditions will warrant PJM to disable the Interconnection Reliability Operating Limit (IROL) interface(s), purpose of this posting is to provide users awareness when PJM disables IROL interface(s) from its TLC program. Informational
Load Shed DirectivePAHThis Emergency Procedure Action is a directive around the shedding of firm load in a local area in order to address an uncontrollable overload(s) on a local transmission facility(ies). Action
Local Minimum Generation EventA Local Minimum Generation Event is implemented when there is an excess generation situation in a localized area or set of areas, which has the potential to result in stability issues or constrained operations. Action
Low Voltage AlertA Low Voltage Alert is issued to heighten awareness, increase planning, analysis, and preparation efforts when heavy loads and low voltages are anticipated in upcoming operating periods. Alert
Maintenance Outage RecallIf PJM determines that it must rescind its approval of a Generator Maintenance Outage of a Generation Capacity Resource that is already underway in order to preserve the reliable operation of the PJM Region, PJM will provide the Member at least 72 hours advance notice. The Member shall be required to make the Generation Capacity Resource available for normal operation within 72 hours and if the generator is not made available for normal operation by 72 hours after the notice of the rescission of the approval of the Generator Maintenance Outage, the remaining time the resource continues on the outage it shall be deemed to have experienced a Generator Forced Outage as set forth in OATT, Attachment K-Appendix, section 1.9.3 (see also OATT, Attachment K-Appendix, section 1.9.4). If PJM withholds, withdraws or rescinds approval of a Generator Maintenance Outage, it shall coordinate with the Member to reschedule the Generator Maintenance Outage at the earliest practical time. Informational
Manual Load Dump ActionPAHThe request to disconnect firm customer load (rotating blackouts). This is issued when additional load relief is needed and all other possible procedures have been exhausted. NERC Energy Emergency Alert (EEA) 3 is issued concurrent with a PJM Load Dump (Shed) Action and is posted on the NERC Reliability Coordinator Information System (RCIS). Target: Electric Distribution Companies Action
Manual Load Dump WarningPAHTo warn members of the increasingly critical condition of present operations that may require manually disconnecting firm customer load (rotating blackouts). Warning
Maximum Generation Emergency/Load Management AlertTo provide an early alert that system conditions may require generation to be loaded above the normal economic limit or if Demand Response is projected to be implemented. NERC Energy Emergency Alert (EEA) 1 is issued concurrent with a Maximum Generation Emergency/Load Management Alert and is posted on the NERC Reliability Coordinator Information System (RCIS). Target: Generation Owners Alert
Maximum Generation Emergency ActionPAHThe purpose is to increase the PJM RTO generation above the maximum economic level. Action
Minimum Generation AdvisoryThis advisory is being issued to provide advanced warning that due to mild weather and light loads, PJM may be entering into Min Gen Alerts and possibly Min Gen Actions during these periods. No action is required from the members at this time. This is an informational notice only. As we approach these valley periods, PJM will implement Min Gen Alerts/Actions on an as needed basis. Advisory
Minimum Generation AlertThe purpose of the Minimum Generation Alert is to provide an early alert that system conditions may require the use of the PJM Emergency Procedures. It is implemented when the expected generation level is within normal minimum energy limits of 2500 MW on the PJM RTO. Alert
Minimum Generation Emergency DeclarationIs to notify members of survey results and strategy, including the anticipated amount of reducible generation to be reduced (by percentage) and a forecast time of the reduction. Warning
Minimum Generation EventIs implemented when the PJM OI dispatcher can no longer match the decreasing load and utilization of emergency reducible generation is necessary. Action
Non-Market Post Contingency Local Load Relief WarnThe purpose of the Non-Market Post Contingency Local Load Relief Warning is to provide advance notice to a transmission owner of the potential for manual load dump in their area only for non-market facilities. Warning
Post Contingency Local Load Relief WarningThe purpose of the Post Contingency Local Load Relief Warning is to provide advance notice to a transmission owner of the potential for manual load dump in their area only. Warning
Pre-Emergency Load Mgmt Reduction ActionPAHThe purpose of the Load Management Reduction Action is to provide additional load relief by using PJM controllable load management programs. Action
Primary Reserve AlertTo alert members of the anticipated shortage of operating reserve capacity (30 minute reserve) for a future critical period. Alert
Primary Reserve WarningPAHTo warn members that available primary reserve (10 minute reserve) is less than required and present operations are becoming critical. Warning
Special NoticeMisc. message Informational
Synchronized Reserve EventNotification around issuances of Synchronized Reserve events. Synchronized Reserves are the reserve capability of generating resources which can be converted fully into energy or Demand Resources whose demand can be reduced within ten minutes from the time of the request. See M-12, Section 4.1.2, for further detail on this procedure. Action
TLRThe NERC Transmission Loading Relief [TLR] Procedure is an Eastern Interconnection-wide process that allows Reliability Coordinators to mitigate potential or actual operating security limit violations while respecting transmission service reservation priorities. For information about the TLR procedure and transmission service priorities, please refer to NERC Reliability Standard IRO-006-5 [Reliability Coordination - Transmission Loading Relief] and IRO-006-EAST-1 [Transmission Loading Relief Procedure for the Eastern Interconnection]. These two documents are available on the NERC Reliability Standards page. (http://www.nerc.com/pa/Stand/Pages/ReliabilityStandards.aspx) Informational
Unit Startup Notification AlertThe purpose of the Unit Startup Notification Alert is to alert members to place units in state of readiness so they can be brought online within 48 hours for an anticipated shortage of operating capacity, stability issues or constrained operations for future periods. Alert
Voltage ReductionPAHThe purpose of Voltage Reduction during capacity deficient conditions is to reduce load to provide a sufficient amount of reserve to maintain tie flow schedules and preserve limited energy sources. A curtailment of non-essential building load is implemented prior to or at this same time as a Voltage Reduction Action. It is implemented when load relief is still needed to maintain tie schedules. PJM dispatch issues the order for a 5% voltage reduction on the distribution system to maintain voltages on the transmission system. Action
Voltage Reduction AlertTo alert members that a voltage reduction may be required during a future critical period. Target: Electric Distribution Companies Alert
Voltage Reduction Warning and Reduction of NCPLPAHA Voltage Reduction Warning and Reduction of Non-Critical Plant Load (NCPL) is issued to warn members that available Synchronized (or Spinning) Reserve (10 minute synchronized reserve) is less than required and present operations have deteriorated such that a voltage reduction may be necessary. Target: Transmission Dispatchers/Generation Dispatchers/LSE Warning