The Woodward 505 8200-1300 is a field‑programmable digital governor for steam turbines with single or split‑range actuators. It features multiple PID controllers, redundant speed inputs, Modbus communication, and flexible start modes. This article provides complete specifications, functional highlights, applications, and technical advantages to support your selection process.
The Woodward 505 series is trusted worldwide for its reliability, programmability, and adaptability in steam turbine control. Model 8200-1300 is the standard LVDC version of the 505 family, designed for single‑actuator or split‑range applications in power generation, mechanical drive, and process industries.
Product Positioning and Model Differences
The Woodward 505 series includes three main variants:
Model | Power Supply | Application |
8200-1300 | 18–32 Vdc (LVDC) | Standard industrial use with low‑voltage DC power |
8200-1301 | 88–132 Vac / 90–150 Vdc | AC or high‑voltage DC power environments |
8200-1302 | 18–32 Vdc | Marine/ATEX certified for hazardous locations |
8200-1300 is the best‑selling base model. It offers identical control functions and I/O as the high‑voltage versions, differing only in the power supply module. For skids or cabinets with existing 24Vdc power, the 8200-1300 is the most economical and reliable choice.
Key Features
1. Five‑PID Control Architecture
The 8200-1300 integrates five interacting PID controllers via a Low‑Signal‑Select (LSS) bus to control the inlet steam valve:
Speed/Load PID – Primary controller for turbine speed or generator load.
Auxiliary PID – Configurable as a limiter or independent controller for generator power, inlet pressure, exhaust pressure, etc.
Auxiliary 2 PID – Limiter‑only mode for additional safety.
Cascade PID – Controls process parameters (e.g., inlet pressure) by adjusting the speed setpoint.
Acceleration Limiter – Limits acceleration during startup to prevent overshoot.
All PID parameters can be tuned online without shutting down the turbine.
2. Flexible Start Modes
Manual Start – Operator controls the trip & throttle valve; the governor controls the speed valve.
Semiautomatic Start – Operator opens the speed valve; the controller automatically accelerates to minimum control speed.
Automatic Start – Fully automated from zero to rated speed, with hot/cold start parameter switching.
3. Intelligent Start Sequencing with Temperature Compensation
Idle/Rated Start – Switch between idle and rated speeds at programmable rates.
Auto Start Sequence – Up to three intermediate speed holds (Idle1, Idle2, Idle3) with independent ramp rates and hold times.
Hot/Cold/Warm Start – Automatically selects curves based on shutdown duration or temperature inputs (thermocouple/RTD).
Temperature difference logic – Improves decision accuracy when using two temperature sensors.
4. Safety and Protection Features
Overspeed Protection – Internal overspeed trip (programmable) and support for external overspeed tests.
MPU Open Wire Detection – Automatically checks speed probe continuity before start.
Critical Speed Avoidance – Up to three speed bands to avoid resonant operation.
Zero Speed Override – Manual or automatic override of loss‑of‑speed trip logic for startup.
Load Rejection – Immediately reduces valve demand to 0% when generator breaker opens.
Emergency Stop Button – Direct hardware action to cut actuator current.
Communication & Integration Capabilities
The 8200-1300 supports multiple industrial protocols for seamless integration with DCS, PLC, HMI, and plant management systems:
Modbus RTU/ASCII – via RS-232/485 port, up to 247 slave addresses.
Modbus TCP/UDP – via two independent Ethernet ports (ports 5001/5002).
Woodward CAN Bus – connect RTCnet, LINKnet HT nodes, VariStroke actuators, etc.
Time Synchronization – SNTP support.
All Modbus addresses can be read or written (if write commands are enabled), allowing remote start/stop, setpoint changes, and status monitoring. By default, each port can be set to read‑only for safety.
Operation & Configuration Modes
User Login Levels
Level | Privileges |
Monitor | View only |
Operator | Start/stop, adjust setpoints, enable/disable functions |
Service | Operator + online PID tuning, calibration |
Configure | Service + change configuration (turbine must be shut down) |
Three Operating Modes
Configuration Mode – Set I/O functions, control strategies, protection values. Enters IOLOCK (all outputs forced to zero).
Calibration Mode – Actuator stroking, valve travel test. Requires shutdown.
Operation Mode – Normal operation: start, stop, monitor, adjust.
Human‑Machine Interface
8.4” LCD, 800×600 resolution, non‑touch (physical keys + navigation cross).
Screen saver (default 4 hours inactivity).
Built‑in tutorial covering navigation, login, parameter adjustment.
Installation & Usage Guidelines
Mounting – Panel mount, 8×10-32 UNF threaded holes. Screw length depends on panel thickness (0.065–0.187 inches).
Grounding – Must connect PE terminal; shield single‑point ground.
Wiring – Use shielded twisted pair; comply with Class I Division 2 or Zone 2 methods.
ESD Protection – Discharge body static before handling; avoid touching circuit boards.
First Use – After configuration, perform valve calibration (minimum/maximum current settings) to ensure 0–100% valve travel matches.
Redundant Configuration – For tracking units, set “Controlled Stop & Trip” to YES to prevent MPU failure trips.
Typical Applications & Industry Cases
Industry | Application |
Thermal Power | Turbine speed control, generator load control, primary frequency response |
Biomass/Waste‑to‑Energy | Small turbine automatic start and load sharing |
Petrochemical | Compressor, pump, fan drives (steam turbine) |
District Heating | Inlet pressure cascade control for stable heat supply |
Marine Propulsion | Marine steam turbines (requires 8200-1302 certified version) |
Industrial Cogeneration | Grid‑connected/island mode switching, load limiting, reverse power prevention |
Comparison & Selection Advice
Feature | Woodward 505 8200-1300 | Other Brands |
Field Programmability | Full parameter configuration, no custom firmware | Often requires vendor intervention |
Number of PIDs | 5 (including acceleration limiter) | Typically 2–3 |
Speed Input Redundancy | Dual channel, auto‑switch | Mostly single channel |
Start Modes | 3 + auto sequence + temperature compensation | 1–2 |
Communication | Ethernet + serial + CAN | Usually serial only |
Certifications | CE, CSA, ATEX, marine | Model dependent |
Selection Guide:
If you have 24Vdc power, choose 8200-1300 for best value.
For AC or high‑voltage DC, choose 8200-1301.
For marine or hazardous (Zone 2) locations, you must choose 8200-1302 (ATEX/marine certified).
Frequently Asked Questions (FAQ)
Q1: Does the 8200-1300 support redundant speed probes?
A: Yes. Two independent MPU/proximity inputs are provided; the controller uses the highest valid speed.
Q2: Can PID parameters be changed while the turbine is running?
A: Yes. Log in as Service or Configure level and adjust proportional, integral, and derivative gains online.
Q3: How can I prevent accidental Modbus writes from tripping the turbine?
A: Each Modbus port can be set to read‑only (Enable Write Commands = NO). Also, the emergency shutdown command can require a two‑step acknowledgment.
Q4: Does the 8200-1300 support isochronous load sharing?
A: Yes. Through Woodward DSLC‑2 or easYgen products via CAN or analog signal.
Q5: What happens to outputs if the controller fails?
A: In IOLOCK state, all relays de‑energize, analog and actuator outputs go to 0 mA (fail‑safe).
