About the 9907-080
Model 9907-080 is an Energize-to-Trip model from Woodward. This model was designed to be used in the ProTech 203 Overspeed Protection series. This unit has a locked NEMA 4X enclosure with optional stainless steel hubs. A key switch to control whether the system is in MONITOR mode or PROGRAM mode prevents unauthorized programming or testing of this ProTech 203 system.
Within this enclosure are three identical speed-sensing units that act independently to monitor prime mover speed and perform speed calculations. Continuous monitoring is achieved using magnetic pickups (MPUs) interfaced with each unit. These units are wired in a two-out-of-three voting configuration. The functional status of each of the three units is monitored using the corresponding operator interface, located on the front of the 9907-080 enclosure. This front panel also has six indicator LEDs. There is one LED per relay within the system. In the event one of the relays is tripped, the corresponding LED will turn on.
The relay configuration of ProTech 203 model 9907-080 allows the system to run with at least two of the three speed-sensing units online, enabling such features as testing of independent units without disrupting operations and hot replacement of any single unit.
The present speed of a unit is displayed on the 9907-080 unit’s interface LCD during normal operation. If an overspeed condition is detected and it exceeds the unit's previously recorded peak speed, the record is updated and stored in non-volatile memory. The peak speed record is only updated when an overspeed condition has occurred.