Description
Key Technical Specifications
The following values are reported in available product identification records. They are not independently confirmed against a Woodward manufacturer datasheet for this exact part number.
| Parameter | Specification |
|---|---|
| Manufacturer | Woodward |
| Model | 8402-271 |
| Product Designation | EPG Speed Control |
| Product Type | Analog Electronic Speed Controller |
| Control Architecture | Analog, hardware-based |
| Nominal Supply Voltage | 24 VDC |
| Reported Supply Range | 18–32 VDC |
| Speed Feedback | Magnetic Pickup (MPU) |
| Actuator Compatibility | Compatible 24 VDC actuator systems |
| Speed Adjustment | Idle and rated speed adjustments |
| Dynamic Adjustment | Gain and stability potentiometers |
| Fuel Limiting | Adjustable fuel-limit function |
| Synchronization Interface | External synchronization bias input, as reported |
| Communication Interface | No digital communication interface reported |
| Mounting | Verify mounting arrangement against the actual unit |
| Operating Temperature | Requires manufacturer documentation for confirmation |
Product Introduction
Woodward 8402-271 Analog Engine Speed Controller
The Woodward 8402-271 is identified in available product records as an EPG analog speed control module. Its reported function is to regulate engine speed using magnetic pickup feedback and an actuator output. Idle speed, rated speed, gain, stability, and fuel-limit adjustments are associated with its control arrangement.
Unlike programmable digital governors, this configuration uses analog adjustment circuits. This makes exact wiring, actuator matching, and original calibration settings important during replacement. Confirm the hardware identity before applying these specifications to an operating engine.
8402-271
Application Scenarios & Field Pitfalls
Engineering Pain Point
A standby diesel generator starts successfully but cannot maintain stable rated speed when electrical load increases. The engine begins hunting, frequency fluctuates, and operators suspect the fuel system.
Before replacing mechanical components, the governor feedback circuit, actuator wiring, and speed-control adjustments should be checked. The Woodward 8402-271, if confirmed as the EPG speed controller, belongs to this type of engine-governor control arrangement.
Typical Applications
- Diesel Power Generation: Engine speed regulation for standby and industrial generator sets.
- Gas Engine Systems: Electronic governor control for compatible gas-fueled reciprocating engines.
- Marine Power Systems: Prime-mover speed regulation for auxiliary generator installations.
- Industrial Engine Applications: Speed control for engine-driven pumps and mechanical equipment.
Technical Pitfalls to Avoid
1. Magnetic Pickup Signal Problems
An unstable magnetic pickup signal can cause governor hunting, speed fluctuations, or failure to recognize engine rotation.
Inspect the following:
- MPU wiring polarity.
- Sensor air gap.
- Cable shielding and grounding.
- Pickup signal amplitude during cranking and normal operation.
Do not compensate for a weak pickup signal by arbitrarily increasing governor gain.
2. Actuator Compatibility
The reported EPG configuration is associated with 24 VDC actuator systems. However, supply voltage alone does not establish actuator compatibility.
Verify actuator model, electrical resistance, current requirements, output characteristics, and mechanical travel. An incorrect actuator can produce unstable speed regulation or excessive heating.
3. Incorrect Gain and Stability Adjustments
The reported adjustment functions include GAIN and STABILITY.
Excessive gain can cause speed oscillation. Insufficient gain can result in sluggish load response. Incorrect stability compensation may introduce additional hunting.
Record the original adjustment positions before making changes. Perform tuning under an approved engine commissioning procedure, not by trial and error during normal plant operation.
Additional identification warning: Some secondary listings identify 8402-271 as a Wärtsilä gas-control solenoid valve rather than an EPG speed controller. These are fundamentally different products. Verify the nameplate, serial number, terminal arrangement, and physical construction before installation.
Related Products
The following Woodward components are relevant to EPG engine-governor installations. They are functional comparisons and supporting components, not confirmed drop-in replacements for 8402-271.
| Model | Product Description | Compatibility and Application |
|---|---|---|
| 8402-257 | Related Woodward part number | Listed alongside 8402-271 in Woodward spare-part inventories. Exact electrical and functional interchangeability requires serial-number verification. |
| 8256-021 | EPG 524, 24 VDC actuator | Actuator component identified in Woodward EPG product catalog information. Check output and mechanical compatibility. |
| 8256-022 | EPG 512, 12 VDC actuator | Lower-voltage actuator option; not a direct substitute for a 24 VDC actuator. |
| 8256-016 | EPG 1724, 24 VDC actuator | Alternative EPG actuator configuration for compatible governor installations. |
| 8256-017 | EPG 1712, 12 VDC actuator | 12 VDC actuator option for appropriately configured engine-control systems. |
| SPM-A | Synchronizer module | Provides synchronization functions for generator applications requiring parallel operation. |
| 9907-018 | 2301A electronic speed controller | Separate Woodward governor family with different electrical and control characteristics. Not a direct replacement. |
| 9905-021 | 2301A reverse-acting speed controller | Alternative governor architecture for applications requiring reverse-acting actuator control. |
Procurement and Replacement Checklist
Before purchasing Woodward 8402-271, confirm:
- Full part number and revision.
- Original manufacturer nameplate and serial number.
- Whether the component is an EPG speed controller or a gas-control solenoid valve.
- Supply voltage and terminal configuration.
- Magnetic pickup and actuator compatibility, if it is the speed controller.
- Original engine or generator application.
- Functional test report and actual product condition.
Final engineering note: The product identity needs confirmation before a replacement decision. Do not use the reported EPG electrical specifications to commission a unit identified as a fuel-control valve. The physical nameplate and original equipment documentation take priority over reseller descriptions.
