9907-150

About the 9907-150

ProTech model 9907-150 is an energize-to-trip overspeed protection device. As with all energize-to-trip models, a prime mover trip might not be triggered by a loss of power. Energize-to-trip overspeed protection models should only be used in applications where de-energize-to-trip versions cannot be used.

This device has three speed-sensing units that monitor prime mover speed, a function carried out by separate magnetic pickups (MPUs) interfaced with each unit. A trip relay is activated when overspeed conditions are detected by at least two of the units, determined by a two-out-of-three hardware vote.

ProTech model 9907-150 samples prime mover speed every 5 ms and has a ±(0.05% x Trip Point in Hz +2 Hz) accuracy rating. The operating temperature range is -25 to +60 °C (-13 to +140 °F), with a range of –15 to +60 °C (+5 to +140 °F) for the display.

The LCD on each operator interface will display an error code when a unit is tripped. Some situations, such as tripped unit or a failed MPU or CPU, will be indicated by an LED on the front panel. There are a few conditions that can be programmed to trigger an alarm output as well.

For details on tunable parameters, error messages, and general 9907-150 product specifications, please refer to Woodward ProTech Overspeed Protection System Manual 85204 (Revision G).