Wrong Signal Shuts Down Cooling Systems

Event Year: 2009 Reliability: Confirmed
Country: United States
Industry Type: Power and Utilities

Duke Energy offers an energy saving program to its customers called the Power Management program.  Participants have a box installed on their air conditioning unit that cycles the cooling system off for a few minutes during peak usage times.  Approximately 18,000 customers participating in the program experienced an outage.  An incorrect signal was sent to the boxes according to a company spokesperson.  As a result, the boxes shut down instead of cycling.  The shutdown lasted for 3 hours.


An incorrect signal was sent to the energy saving air conditioning control boxes.  Instead of cycling, the units were shut down for 3 hours.