The Woodward 8405-307 Speed Controller is a specialized engine control unit historically used as part of the ST-125™ control system. It was designed primarily for managing Stanadyne DB-4 series diesel fuel injection pumps, ensuring precise speed maintenance in various industrial prime mover applications.

Please note: This product has been discontinued by the manufacturer. If you are looking for a replacement, Woodward typically recommends upgrading to modern solutions like the L-Series Speed Controller (e.g., 8404-5003), which combines actuator and control functionality into a single integrated package.

⚙️ Product Parameters

• Model Number: 8405-307
• Series: ST-125™ Control System
• Primary Application: Stanadyne DB-4 Series Diesel Pumps
• Operating Voltage: Supports both 12 VDC and 24 VDC operation
• Weight: Approx. 1.20 lbs (0.54 kg)
• Origin: United States
• Key Features: Start fuel limiting, precise position feedback, and dual-method shutdown (solenoid retention + Run/Stop feature)

 

💡 Frequently Asked Questions (Q&A)

What should I do if my 8405-307 controller fails?

Since the unit is discontinued, you may have difficulty finding “New in Box” units. It is highly recommended to migrate to a current production model, such as the Woodward L-Series controller. This transition may require an installation kit (like 8923-1253) and a programming harness.

Is this controller field-repairable?

No. Woodward does not support field-level repairs for this specific electronic control board. If the unit is faulty, the standard industry practice is to replace the module or upgrade the entire control system to a modern, supported version.

Can I use the existing wiring for an upgrade?

In many cases, the L-Series electrical harness can be installed using the existing wiring from the ST-125 setup, though a programming harness and configuration software will be necessary to set the correct speed set points, overspeed protection, and dynamics.

What environments is this controller suited for?

The 8405-307 must be mounted in a protected environment, such as an electrical cabinet or a sheltered skid area. It is not designed to be exposed directly to water, excessive dirt, or harsh weather conditions.

 

🚀 Recommended Woodward Series & Models

• 8404-5003 (L-Series Speed Controller – Recommended upgrade path)
• 9907-205 (Digital Speed and Process Controller)
• 3062322 (Speed Governor Control)
• 07CON-SA4450 (APECS Digital Speed Controller)
• 8405-309 (ST-125 Compatible Actuator)
• 8405-315 (ST-125 Compatible Actuator)
• 8923-1253 (L-Series Installation Kit)
• 8923-1061 (Programming Harness)
• 9927-1222 (L-Series Service Tool Software)
• 26250 (L-Series Speed Control Manual)