Description
The Woodward 8200-205 is a digital overspeed protection assembly within the legacy ProTech 203 system architecture. This dedicated hardware system is engineered to provide emergency shutdown capabilities for steam turbines, gas turbines, and heavy industrial prime movers by continually evaluating structural rotational speeds. The 8200-205 variant operates on a high-voltage 220 V AC electrical configuration and executes a baseline de-energize-to-trip voting circuit matrix.
Technical Specifications
| Parameter | Value / Detail |
| Model Number | 8200-205 |
| Product Line | ProTech 203 |
| Input Supply Voltage | 220 V AC nominal |
| Trip Action Logic | De-energize-to-Trip (Failsafe under power loss) |
| Input Sensor Compatibility | 3 Independent Magnetic Pickup (MPU) Channels |
| Trip Frequency Range | 250 Hz to 25 kHz |
| Frequency Measurement Accuracy | 0.05% of point \pm 2 Hz across the temperature window |
| Internal Processing Loop Sample Rate | Speed vectors sampled every 5 ms |
| Total System Electrical Response Time | 40 ms maximum from threshold breach to relay drop |
| Enclosure Protection Footprint | NEMA 4/4X (Lockable front access door panel) |
| Operational Temperature | −25 to +60 °C (−13 to +140 °F) |
| Physical Component Weight | Approximately 13 lbs 1 oz (5.9 kg) before packaging |
| OEM Reference Documentation | Product Manual 85205 |
Technical Features & Field Engineering Context
Two-Out-Of-Three (2oo3) Internal Voting Architecture
The ProTech 203 system utilizes three physically distinct, completely isolated sub-modules (Unit A, Unit B, and Unit C) within a single lockable NEMA enclosure. Each sub-module possesses its own separate processor, display interface, and unique MPU frequency tracking channel. The dry output contacts of these units are hardwired internally into a two-out-of-three matrix.
- Operational Security: If a single MPU experiences an intermittent failure or open-circuit wire fault, the individual sub-module will register a local fault, but the machine will not trip. This eliminates spurious shutdowns caused by dynamic sensor vibration on turbine brackets.
- Live Sub-Module Replacement: The internal hardware layout supports the hot-replacement of a single processor sub-module while the turbine remains on-line and the external protection loop remains armed.
De-Energize-to-Trip Logic Constraints
As a de-energize-to-trip architecture, the main output relays remain continuously energized during healthy turbine runtime. Any total disruption of the 220 V AC source supply immediately forces the contacts to drop out, executing a hardware-level emergency trip. In the field, this requires clean, uninterruptible power distribution topologies. If the plant’s 220 V AC bus suffers from switching transients or severe harmonic distortion, interposing voltage stabilization infrastructure is mandatory to prevent accidental turbine drops.
Speed Pickup Fail Timers
During initial zero-speed start sequences, magnetic pickups cannot generate adequate voltage magnitudes due to low tooth-pass velocities. The 8200-205 implements an configurable MPU fail timer routine. Upon entering a start or reset state, the module overrides the low-frequency error condition for a determined timeout period (e.g., 60 seconds). If the prime mover fails to accelerate past the minimum MPU input threshold before the timer runs out, the unit safely aborts the sequence and triggers a trip.
Commercial and Logistics Status
- Condition: Refurbished (Trace-tested and bench-certified via multi-channel frequency synthesizers) or New Surplus.
- Warranty Period: 12-month comprehensive protection systems warranty from the date of tracking dispatch.
- Global Lead Time: Standard refurbished configurations ship within 3 to 6 business days.
- Documentation: An itemized calibration test sheet listing verified frequency thresholds should be retained prior to installing hardware into working emergency protection lines.
Commercial Note: The ProTech 203 series is a legacy safety platform replaced in contemporary configurations by the ProTech-G or ProTech SX families. Availability shifts with global plant decommissioning cycles. Listed market pricing is indicative; contact our procurement team for a firm commercial quote.
Frequently Asked Questions
What happens if I connect 24 V DC power into the 8200-205 terminal rail?
The 8200-205 is wound and fitted with internal transformers explicitly engineered for a 220 V AC line input. Applying low-voltage DC directly to the primary power rail will fail to initialize the internal power supply circuits, keeping all three units dark. For 24 V DC infrastructures, the alternative part number 8200-201 must be sourced instead.
Can the overspeed trip point be modified via Modbus networks while the turbine is online?
No. The ProTech 203 series does not allow safety parameter writes via remote communication networks. All overspeed setpoint modifications must be input directly through the front-panel tactile membrane keypads on each individual module. This design choice prevents software hacking and satisfies standard industrial security layer definitions.
Can different types of speed probes be mixed across the three input channels?
While technically the internal circuits can parse any clean AC frequency signal from 250 Hz to 25 kHz, standard engineering practice dictates using three identical magnetic pickups with equivalent coil impedances and matching gear wheel distances. Mismatched probe impedances introduce phase and amplitude variations that can skew measurement synchronization across the 5 ms sampling loops.
