Woodward 9907-151 ProTech 203 220 V AC De-energize-to-Trip Overspeed Protection System
A three-unit ProTech 203 execution with 220 V AC input on units A, B and C and de-energize-to-trip relay logic.
Product Overview
9907-151 is the 220 V AC, de-energize-to-trip ProTech 203 system part number. All three independent speed-sensing units use the same 220 V AC supply class.
The permitted supply range for each unit is 180 to 264 V AC with a listed consumption of 16.4 VA. Each unit receives a magnetic-pickup signal and contributes to the hardware two-out-of-three trip vote.
The exact part number controls both supply and relay philosophy. A different 9907-series ProTech 203 number must not be selected only because the enclosure or front panel appears similar.
Performance
Sense three independent speeds
Units A, B and C each calculate speed from their own magnetic-pickup signal.
De-energize on the trip decision
The 9907-151 execution uses de-energize-to-trip logic for the documented relay arrangement.
Vote two out of three
Hardware voting requires two trip paths to produce the system trip output.
Technical Details
| Manufacturer | Woodward | Exact model | 9907-151 |
|---|---|---|---|
| Product family | ProTech 203 | Trip execution | De-energize to trip |
| Unit A supply | 220 V AC | Unit B supply | 220 V AC |
| Unit C supply | 220 V AC | Permitted input range | 180 to 264 V AC per unit |
| Power requirement | 16.4 VA per unit | Speed inputs | Three magnetic pickups |
| Trip vote | Two out of three | ||
About IndustryParts
https://www.industryparts.com/Supply and relay philosophy are verified together
IndustryParts keeps the 9907-151 identity, three-unit power record and protection evidence together before preparing a quotation.
- •Exact submitted model retained
- •Installed-system evidence reviewed
- •Requested quantity linked to the enquiry
System Integration
Verify all three supplies
Record isolation, branch protection, grounding and the independent supply wiring for units A, B and C.
Archive trip interfaces
Capture the overspeed settings, relay terminal schedule and turbine shutdown logic.
Retain sensor evidence
Document each MPU, cable, tooth count, normal speed and overspeed test method.
Complete the protection test
Verify all speed channels, de-energize relay action, voting and final trip-system response.
Applications
Turbine overspeed protection
Providing three independent magnetic-pickup channels and a voted shutdown decision.
220 V AC installations
Maintaining the exact three-unit power execution documented by the 9907-151 part number.
Legacy protection-system service
Replacing controlled components while retaining settings, relay philosophy and final trip evidence.
FAQ
Can a 9907-150 replace 9907-151?
No automatic substitution should be made: 9907-150 is an energize-to-trip execution, while 9907-151 is the de-energize-to-trip 220 V AC system.
What power evidence should accompany 9907-151?
Provide the supply voltage, branch protection and terminal records for units A, B and C, not only the enclosure nameplate.
Why must all three MPU records be retained for 9907-151?
Each unit calculates speed independently, so sensor type, tooth count, gap and cable evidence are needed for every channel.
How should the voting path be checked after 9907-151 service?
Prove each channel and then verify the documented two-out-of-three relay action through the turbine shutdown interface.
What closes a 9907-151 replacement record?
Matched part number, correct de-energize behavior, stable speed indication, verified voting and a completed trip-system test provide acceptance evidence.
Request a model-specific quotation
Send the complete 9907-151 label, requested quantity, delivery destination and installed-system context.
