9905-883

About the 9905-883

Model 9905-883 is one of the available versions in the ProTech 203 Overspeed Protection System series. This Woodward series has both energize-to-trip and de-energize-to-trip versions. Model 9905-883 is a de-energize-to-trip version. This is one of the models in which not all of the speed-sensing units have the same power supply. In this model, Units A and B both have 120 Vac/dc power supplies; the power supply for Unit C is 220 Vac.

Installation and operation information may be found online in the Woodward ProTech 203 Overspeed Protection System Manual 85191 (version B).

This ProTech overspeed protection device uses magnetic pickups (MPUs) to detect overspeed conditions and activate a trip relay in response. If any of the 9905-883 MPUs fails, lose signal or have wiring issues, the problem will be indicated by one of the corresponding unit’s LED indicators. The 9905-883 model has a speed sample time of 5 ms and an overall system response time of 40 ms max.

The current actual speed of any one of the 9905-883 units can be viewed on that unit's LCD. This is also where the peak speed can be viewed. If an overspeed condition occurs and a new peak speed is recorded, that new peak speed is stored in non-volatile memory. This model has an accuracy rating of 0.1% at 25 °C.