Description
Woodward ESDR4
Technical Specifications:
- Power Supply: 24 VDC or 120/240 VAC optional
- Input Signal: 5A secondary current transformer input
- Droop Adjustment Range: 0% to 8% adjustable
- Response Time: Fast response for load change
- Operating Temperature: -20 °C to +70 °C
- Storage Temperature: -40 °C to +85 °C
- Enclosure: DIN rail mount plastic housing
- Isolation: Galvanic isolation between CT input and governor output
Function Features:
- Adjustable speed droop characteristic for paralleled generator load sharing
- Receives CT current signal to generate speed bias correction signal
- Stabilizes bus frequency during load variation for parallel gensets
- Low power consumption solid state electronic circuit
- Built-in overcurrent protection for CT input circuit
- Simple potentiometer adjustment for droop setting
- LED power status indicator
- Compatible with most Woodward analog and digital governors
Application Scenarios:
- Diesel generator parallel operation control systems
- Gas engine genset load sharing cabinets
- Legacy generator governor retrofit projects
- Marine generator parallel power systems
- Industrial backup power plant spare parts replacement
Material Composition:
- Housing: Black flame retardant plastic enclosure
- Main PCB: FR4 fiberglass printed circuit board
- Core Components: Current sampling transformers, analog operational amplifiers
- Adjustment Components: Multi-turn potentiometer for droop setting
- Terminals: Screw copper terminals for CT input and governor signal wiring
Structural Features:
- Compact rectangular plastic housing for DIN rail mounting
- Front panel potentiometer for droop percentage adjustment
- LED power indicator on front surface
- Screw terminal blocks on one side for field wiring
- Internal PCB fixed with insulation supports
Working Principle: Current transformer secondary current signal enters ESDR4 input terminals. Internal sampling circuit measures generator output current. The circuit generates speed bias signal proportional to generator load current and sends signal to generator governor. This signal creates predefined speed droop characteristic. When generator carries more load, governor receives bias signal to slightly reduce speed reference, which distributes total bus load evenly among multiple paralleled generators and stabilizes parallel operation.
Installation Requirements:
- Mount ESDR4 on DIN rail inside generator control cabinet
- Wire CT secondary circuit strictly following polarity marking
- CT secondary circuit must not be open circuit during operation
- Separate CT wiring from low voltage governor signal wiring
- Connect module protective earth terminal
- Keep away from high noise contactors and ignition coils
Usage Notes:
- Adjust droop potentiometer to set target droop percentage during commissioning
- Verify CT ratio matches module input specification
- Never open CT secondary circuit while generator is running
- Disconnect power and short CT terminals before wiring maintenance
- Check terminal tightness periodically under vibration environment
- Avoid overcurrent input to protect internal sampling circuit
