PRODUCT INFORMATION
Product Overview
The Woodward 9907-149 ProTech 203 Overspeed Protection System monitors prime mover shaft speed. It features three independent speed-sensing units labeled Unit A, Unit B, and Unit C. Each individual unit operates with a nominal 120 VAC/DC power input. Trip relays across the three units are wired in a hardware two-out-of-three voting arrangement. The system initiates an overspeed trip when at least two units detect an overspeed condition.
This 9907-149 model uses a de-energize-to-trip architecture to protect machinery during power loss. Each independent sensing unit interfaces directly to a dedicated magnetic pickup speed sensor. The assembly mounts inside an industrial enclosure rated NEMA Type 4/4X or IP54. A modular hardware design allows online replacement of a single sensing unit during machine operation.
TECHNICAL DATA
Technical Specifications
| Parameter | Specification |
|---|
| Trip configuration | De-energize to trip |
|---|
| Independent sensing units | Three: A, B, and C |
|---|
| Power per sensing unit | 120 VAC/DC nominal |
|---|
| AC input range per unit | 88–132 VAC; 12.5 VA |
|---|
| DC input range per unit | 90–150 VDC; 4.77 W |
|---|
| Speed inputs | Three independent magnetic pickups |
|---|
| Decision logic | Hardware two-out-of-three vote |
|---|
| Speed sensing frequency | 100 Hz–32 kHz |
|---|
| Trip frequency | 250 Hz–25 kHz |
|---|
| MPU minimum amplitude at 100 Hz–25 kHz | 1 Vrms |
|---|
| MPU minimum amplitude above 25 kHz | 2 Vrms |
|---|
| MPU maximum amplitude | 25 Vrms |
|---|
| MPU input impedance | 2 kohm |
|---|
| Trip speed setpoint | 250–25,000 rpm |
|---|
| MPU failure setpoint | 100–25,000 rpm |
|---|
| MPU failure timeout | 1 second–533 minutes 20 seconds |
|---|
| Configurable gear teeth | 20–120 |
|---|
| Speed sample period | 5 ms |
|---|
| Maximum total response time | 40 ms |
|---|
| Operating temperature | -25 to +60 °C |
|---|
| Display operating temperature | -15 to +60 °C |
|---|
| Enclosure | NEMA Type 4/4X (North America); IP54 (Europe) |
|---|
| Installed weight | 7.3 kg |
|---|
TECHNICAL INFORMATION
Features
- Hardware two-out-of-three voting logic across three independent sensing units
- Fail-safe de-energize-to-trip output relay configuration
- Modular architecture allowing online replacement of a single sensing module
- High-speed digital sampling with a 5 millisecond calculation interval
- Maximum total system response time of 40 milliseconds
- Dedicated front-panel digital displays and status indicators per sensing unit
- Configurable prime mover gear tooth profile from 20 to 120 teeth
- Built-in magnetic pickup sensor failure detection with programmable timeout
TECHNICAL INFORMATION
Applications
- Steam turbine emergency overspeed protection
- Gas turbine rotor overspeed trips and safety interlocks
- Industrial prime mover shaft overspeed trip systems
TECHNICAL INFORMATION
Connections / Interfaces
- Three dedicated magnetic pickup input channels
- Independent 120 VAC/DC power terminal connections for Unit A, Unit B, and Unit C
- Remote system reset field wiring terminals
- Twisted-pair shielded cable terminations with jumper from terminal 13 to terminal 3
TECHNICAL INFORMATION
Installation Guidelines
- Provide an external disconnecting switch identifiable to each individual power supply unit.
- Mount the enclosure in a location maintained between -25 °C and +60 °C.
- Use twisted conductor pairs with foil or braided shielding on all magnetic pickup lines.
- Limit exposed wiring beyond cable shields to a maximum length of 50 mm.
- Isolate signal wiring away from high-voltage cables and electromagnetic interference sources.
TECHNICAL INFORMATION
Configuration Guidelines
- Select the exact number of prime mover gear teeth between 20 and 120.
- Program the overspeed trip speed setpoint within the range of 250 to 25,000 rpm.
- Define MPU failure parameters between 100 and 25,000 rpm with appropriate timeout settings.
TECHNICAL INFORMATION
Compatibility
- Woodward passive magnetic pickups meeting minimum input amplitude requirements
- Prime mover monitored tone wheels with 20 to 120 gear teeth
TECHNICAL INFORMATION
Compliance and Certifications
- NEMA Type 4/4X enclosure rating
- IP54 ingress protection rating
TECHNICAL RESOURCES
Documentation
COMPATIBILITY
Compatibility & Replacement
COMPATIBLE MODELSWoodward passive magnetic pickups meeting minimum input amplitude requirements Prime mover monitored tone wheels with 20 to 120 gear teeth
Verify compatibility against the exact Part Number, revision and manufacturer documentation before ordering.
PART VERIFICATION
Before You Order
Industrial automation parts can share similar model names, suffixes and revisions. Confirm the complete manufacturer Part Number before purchase.
01Check Part NumberMatch the complete ordering code on the existing unit.
02Confirm RevisionCheck suffix, hardware or firmware when applicable.
03Send a Label PhotoWe can review a clear label photo when identification is uncertain.
ORDERING PROCESS
From RFQ to Dispatch
1Submit Part Number2Verify Product Identity3Confirm Stock & Condition4Issue Quotation5Dispatch & Tracking
PRODUCT FAQ
Frequently Asked Questions
What power input does each unit of the Woodward 9907-149 require?
Each of the three units requires a nominal 120 VAC/DC power supply. The AC operating range is 88 to 132 VAC at 12.5 VA. The DC range is 90 to 150 VDC at 4.77 W.
How does the voting architecture function on the Woodward 9907-149?
The system uses three independent sensing units connected in hardware two-out-of-three voting logic. An overspeed trip triggers if any two units simultaneously detect an overspeed condition.
Can a failed sensing unit be replaced while the turbine is online?
Yes. The modular design allows an individual unit replacement while the turbine runs. The remaining two units maintain full two-out-of-three protection logic during service.
What is the market reference price for the Woodward 9907-149?
Observed market reference pricing is approximately $4,980 USD for refurbished condition. These figures are indicative market reference pricing only and are not a final quotation.
