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3 year warranty

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ProTech 203 digital overspeed trip device that senses prime mover speed through three magnetic pickups (MPUs). Woodward Model 9905-998



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  • Part Number: 9905-998
  • SKU: 9905998WO
  • Manufacturer: Woodward
  • Series: ProTech 203 Overspeed Protection

9905-998 Technical Specifications

Dimensions W19in x H12.244in x D5.62in
Features CPU Failure Indication
Input Voltage 24 Vdc = 18–32 Vdc, 7.25 W
Keypad/Display 1 Keypad and Display per Module
Manual 85196
Manufacturer Woodward
Model De-energize-to-Trip
NEMA Rating 4x/IP54
Operating Temperature –13 to +140 °F
Weight Less than 17 lbs

Product Description

Magnetic pickups (MPUs) monitor prime mover speed in this Woodward ProTech overspeed protection model. Each one is interfaced with a different speed-sensing unit, units A, B, and C. These MPUs can be set to a Failed Set Point range of 100 rpm to 25,000 rpm, and a Failed Timeout range of 1 second to 533 minutes 20 seconds.

The MPUs and three speed-sensing units sample prime mover speed every 5 ms. If a hardware two-out-of-three vote determines an overspeed condition is met, a trip relay is activated. The total response time for this de-energize-to-trip system is a maximum of 40 ms. Units A, B, and C are in a locked enclosure, that is NEMA 4X certified when the optional stainless steel hubs are used. Each unit has its own 24 Vdc power supply.

ProTech model 9905-998 has many features, including:

  • Hot replacement – individual units may be replaced without taking the prime mover offline
  • Built-in self-test – individual units may be tested while the prime mover is online
  • Operator interfaces – one per speed-sensing unit
  • LED indicators – separate LEDs to indicate a unit trip, MPU failure, or failed CPU
  • Remote reset – Units A, B, and C may be reset from a remote location
  • Restricted access to PROGRAM mode – units are switched between MONITOR mode and PROGRAM mode by using a key switch that is located inside the locked enclosure

Woodward ProTech manual 85196 has full details on the features of overspeed protection model 9905-998, including all of the functions achieved through the operator interface keypad and LCD.

Reviews For 9905-998

Internal Review

Whenever two of the three speed-sensing circuits sense an overspeed condition, the voter relay configuration will change state, causing a turbine trip. It should be noted, however, that a single MPU or circuit failure will not cause an inadvertent trip. - AX Control Tech Team

Repair Services For 9905-998

Type Lead Time Price Action
Repair Service 1-2 weeks $5134

Our highly skilled technicians can repair your 9905-998. All of our repairs come with a 3 Year AX Control Warranty. Please contact us for additional information about our repair process. To receive the repair pricing and lead time listed above please process your repair order via our website. The following repair options may be available upon request:

  • 48-72hr Rush Repair
  • Detailed Repair Reports
  • AX Control Certificate of Warranty

AX Control Warranty Info

All products we sell are backed by our unparalleled warranty. A warranty certificate will be provided with your order upon request.
All PLCs, HMIs, and Turbine Control Boards: 3 Years
All AC/DC and Servo Drives: 2 Years
All Motors: 1 Year
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9905-998 Manuals, White Papers, Data Sheets, and Troubleshooting