9907-081

About the 9907-081

Part 9907-081 is an overspeed protection system with a modular design. Key features of this Woodward ProTech 203 system include:

• NEMA 4X certified enclosure – there are optional stainless steel hubs for the enclosure. These must be used to be NEMA 4X certified
• Key switch to access programming – a single key switch connected to all three speed-sensing units controls switching between PROGRAM mode and MONITOR mode
• Hot replacement – individual speed-sensing units may be replaced (or tested) while the system is running
• Two-out-of-three vote configuration – speed-sensing unit voter relays rely on two of the three units detecting overspeed conditions to trip the system and turn off the turbine. One tripped unit will not disrupt operations.
• Remote reset – this feature allows units to be reset from a remote location. Units need to be reset after a trip and before starting the turbine
• Six LED indicators – one LED per voter relay. LEDs illuminate when the corresponding relay is tripped.

Model 9907-081 has separate power supplies for the speed-sensing units. All three units in this ProTech 203 model are 120 Vac/dc voltage input with a voltage range of 88-132 Vac/90-150 Vdc, 7.25 watts.

Overspeed protection systems in the Woodward ProTech 203 series are sensitive to vibration and electromagnetic interference and should be installed somewhere they are protected from high-voltage and high-current devices. Precautions must also be taken to protect this energized-to-trip system from direct sunlight and moisture. Woodward manual 85203 has details on location requirements, as well as additional product specs.