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Wrong Signal Shuts Down Cooling Systems

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

Description

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.

Impact

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