NPCC and the
Market Rules specify requirements for disturbance reporting to be met by their members and market participants. A system disturbance is an unplanned event that produces an abnormal system condition on the bulk electricity system. It may be associated with a fault and be characterized by the loss of power system stability, cascading outages of transmission circuits or abnormal ranges of frequency or voltage.
Reliability Incident Reports
Manby H1L15 Breaker Incident — July 5, 2010
This report discusses the breaker explosion at the Manby Transformer Station that occurred on July 5, 2010 and resulted in a load interruption of over 1,550 MW, affecting over 240,000 people in the Greater Toronto Area (GTA).
Richview SC22 Incident — January 30, 2007
This report documents the incident on January 30, 2007 in which a 3-phase fault occurred at the Richview Transformer Station resulting in the loss of approximately 1,500 MW of load in Ontario.
Cherrywood Circuit Breaker Incident — December 12, 2005
On December 12, 2005 a circuit breaker air fill valve that failed resulted in a stuck breaker and precipitated the incident described by this report.
Energy Shortfall and Voltage Reductions — August 3 and 4, 2005
This report describes the events leading up to and during the energy shortfalls on August 3 and 4, 2005.
Milton Fault and Voltage Excursion — May 27, 2005
An investigation into the incident on May 27, 2005, when a 3-phase to ground fault led to the loss of approximately 2,300 MW of load in Ontario and voltage oscillations that were observed by neighbouring interconnected utilities.