Product Description
Woodward 9905-857 2301D-ST Digital Speed Control
Product Overview
- The Woodward 9905-857 is a 2301D-ST Digital Speed Control designed for precise speed regulation of steam turbines in industrial applications, such as power generation, marine propulsion, and mechanical drive systems. Part of Woodward’s 2301D series, this microprocessor-based controller provides advanced speed control, load sharing, and protection for small to medium-sized steam turbines. The “ST” designation indicates its specific configuration for steam turbine applications, offering features like isochronous speed control, droop control, and compatibility with Woodward actuators. The 9905-857 is ideal for single-unit or parallel operation, ensuring stable turbine performance under varying load conditions. Compared to Woodward’s analog governors (e.g., DYN1-10784-003-0-12) or genset controllers (e.g., EasyGen-3200-5, 8440-2050E), the 2301D-ST focuses on steam turbine speed control, not engine or generator management. It is distinct from Woodward’s protection relays (e.g., XD1G11), MicroNet CPU modules (e.g., 5501-381), communication modules (e.g., SST-ESR2-CLX-RLL), excitation systems (e.g., DECS-100-B15), and actuators (e.g., 8408-921).
Technical Specifications
- The 9905-857 has the following specifications based on industry sources and Woodward documentation:
| Specification | Details |
|---|---|
| Model/Part Number | 9905-857 |
| Manufacturer | Woodward |
| Description | 2301D-ST Digital Speed Control for Steam Turbines |
| Series | 2301D |
| Function | Regulates steam turbine speed, load sharing, and protection |
| Processor | Microprocessor-based (specific architecture not publicly detailed) |
| Memory | Flash: 4–8 MB (for firmware and configuration) RAM: 2–4 MB (for runtime data) |
| Display | No onboard display; LED indicators for status; configuration via external PC or HMI |
| Inputs | 2 speed inputs (magnetic pickup or proximity probes, 0.5–15 kHz) 4 analog inputs (configurable for 4–20 mA or 0–5 V, e.g., load sensor, remote setpoint) 4 discrete inputs (24 VDC, for start/stop, reset, or mode selection) |
| Outputs | 1 actuator output (4–20 mA or 0–200 mA, compatible with Woodward actuators) 2 analog outputs (4–20 mA, for speed or load monitoring) 3 relay outputs (dry contact, up to 250 VAC/2 A, for alarms or trips) |
| Communication Interfaces | 1 serial port (RS-232 or RS-485, Modbus RTU) USB (for configuration and diagnostics) |
| Control Modes | Isochronous speed control, droop control, load sharing, critical speed avoidance |
| Speed Regulation Accuracy | ±0.25% of rated speed (steady-state) |
| Protection Functions | Overspeed protection, actuator fault detection, loss of speed signal |
| Redundancy | Non-redundant |
| Diagnostics | Fault detection, event logging (up to 100 events), status LEDs, real-time monitoring via Modbus |
| Compatibility | Woodward actuators (e.g., TG, PG, ProAct), magnetic pickups, proximity probes; third-party devices via Modbus RTU; integrates with SCADA systems |
| Power Supply | 18–40 VDC (24 VDC nominal) |
| Power Consumption | Approx. 10–15 W |
| Environmental Specifications | Operating Temperature: -40°C to +70°C (-40°F to +158°F) Storage Temperature: -40°C to +85°C (-40°F to +185°F) Relative Humidity: 5% to 95% non-condensing Vibration: IEC 60068-2-6 compliant Shock: IEC 60068-2-27 compliant |
| Enclosure | IP20 (requires enclosure for harsh environments) |
| Dimensions | Approx. 330 mm (H) x 190 mm (W) x 90 mm (D) |
| Weight | Approx. 1.5–2 kg |
| Mounting | Panel-mounted or chassis-mounted (via mounting brackets) |
| Certifications | CE, UL, CSA, marine certifications (e.g., DNV, ABS, configuration-dependent); ATEX/IECEx Zone 2 (optional) |