9905-984

About the 9905-984

The front panel of parts 9905-984 has three operator interfaces, one for each of the three identical speed-sensing units. Each one has a two-line LCD, touchpad, and potentiometer. There are also separate 24Vdc power supplies for each unit A, B, and C.

These front panel operator interfaces are where parameters are set, speed and operations are monitored, and error codes are displayed. Each unit has separate LEDs to indicate conditions such as an MPU failure (or failure in its wiring), a CPU not functioning normally, and a tripped unit. Alarm outputs can also be set for some conditions.

Model 9905-984 is part of the ProTech 203 Overspeed Protection System series. This series is manufactured by Woodward. ProTech 203 overspeed protection device model 9905-894 samples speed every 5ms using magnetic pickups, one in each speed-sensing unit. From these speed samples, the units perform separate speed calculations which are then used in a hardware two-out-of-three vote to determine whether overspeed conditions are met. If an overspeed condition is detected, a trip relay is activated.

Additional features of ProTech 203 model 9905-984 include:

• Hot replacement
• Online testing
• Remote reset
• Key locked enclosure

The enclosure of model 9905-984 is NEMA 4X when the optional stainless steel hubs are used. For more information and product specifications for this ProTech 203 device, please see Woodward manual 85195.