9905-980

About the 9905-980

There are three individual speed-sensing units in this overspeed protection device. Units A, B, and C are identical. Each one has:

• Magnetic pickup (MPU) monitoring prime mover speed
• 220 Vac power supply
• LCD displays nine parameters, such as the unit’s current speed
• Keypad
• LED functional status indicators
• Alarm output

The three units are configured for a two-out-of-three hardware vote to detect overspeed conditions and activate a trip relay when necessary. If only one of the three units detects an overspeed condition, that unit will trip while the other two remain online and in control of the system, and continue providing an accurate output. 9905-980 is a de-energize-to-trip model.

Hot replacement, online testing of individual units, and continued operation with a single-tripped unit, are all features made possible by the modular design of parts 9905-980. Additional features of this ProTech 203 overspeed protection device include LED indicators, alarm outputs, and a locked enclosure that meets IP 65 and NEMA 4 standards.

The locked enclosure of the 9905-980 system helps prevent unauthorized access to switch between MONITOR mode and PROGRAM mode.  The system will operate in either mode, but should only be put in PROGRAM mode when the unit needs to program or changes need to be made to any of the system’s tunable parameters, such as Trip Speed Set Point and MPU Failed Set Point.

Product info for Woodward ProTech 203 model 9905-980 can be found in manual 85195, with additional relevant information in manuals 82715, 82510, and 50532.