Turbine overspeed is the one trip
function of a turbine that is considered a safety issue. If a turbine
overspeeds, serious injuries to personnel and property damage can
result. The insurance industry statistics show that turbine overspeeds
are the number one cause of injuries and property losses in
petrochemical and refining facilities.
When it comes to safety, no other
manufacturer can mach the Triconex reputation for availability,
reliability and performance. The TurboSentry overspeed trip system is
designed to provide reliable overspeed trip protection while assuring
high availability.
The TurboSentry provides overspeed trip protection for
rotating equipment. The need for using an electronic overspeed trip
device has arisen from the difficulties with ensuring that mechanical
overspeed protection devices operate properly. The TurboSentry is a
triplicated overspeed trip device that monitors up to three magnetic
speed pickups and will trip the turbine if at least two of the pickups
detect an overspeed condition simultaneously. Two Form-C relays take the
separately voted trip information and activate accordingly. The
TurboSentry is designed to meet API 612 requirements for special purpose
steam turbine overspeed trip protection. Features include:
-
Less than 30 millisecond response time
-
Three independent processors executing 2-out-of-3
voting
-
Provisions for multiple, independent speed
measurement gears
-
Quick, user friendly setup and testing
-
On-line confirmation of trip functions
-
Redundant power supplies
-
Records highest measured speed (last trip speed)
-
Redundant trip and alarm contact outputs
-
Optional NEMA 4X enclosure
-
Accurate speed measurement - within 0.01%
-
Wide speed range - 250 to 30,000 Hz
-
Two out of three voting
-
API 612 Compliant
