Protection upgrade reduces stress on the gas turbine, reduces downtime and improves startup reliability

Mechanical overspeed trip mechanisms require periodic overspeed testing that stresses rotating components, extends outages and can cause failed starts with the need for manual resets. This solution includes additional speed sensors and a new main electronic overspeed trip (MEOST) system to replace existing mechanical systems.


  • Redundant electronic overspeed trip protection systems
  • Upgraded logic to support MEOST and online system testing
  • Addition of new speed sensors to create the MEOST
  • Prevention of single valve failure tripping the GT
  • Individual channel testing without tripping the GT


  • System operation can be verified online without tripping the GT, allowing extension of current annual recommended testing interval and testing whenever desired
  • Improves system and starting reliability
  • Shorter outages by eliminating repair or reset of mechanical trip mechanism
  • Reduces stress cycles from overspeed operation and trips/restarts
  • Individual testing of solenoid valves to discover issues before any planned or unplanned downtime
  • Reduces maintenance costs


  • Mitsubishi Power technical advisors can install the MEOST solution during a turbine or major inspection.