Description
Product Overview
The Woodward 9905-028 is a SPM-A series synchronization module designed for industrial generator and turbine control systems. It serves as a critical interface for synchronizing offline generators/turbines with an online system (e.g., utility grid or another generator) before paralleling. As part of Woodward’s SPM-A ecosystem—widely recognized for precision synchronization—the 9905-028 is optimized for applications requiring strict adherence to grid frequency/phase standards (e.g., power plants, marine auxiliary power, industrial cogeneration).
Its core function is to match the offline unit’s frequency, phase, and voltage to the online system within tight tolerances, then send a signal to close the circuit breaker—enabling smooth power transfer without electrical faults (e.g., phase mismatch, frequency surges). Unlike basic synchronizers, the 9905-028 integrates seamlessly with Woodward’s 2301A load-sharing controllers for end-to-end parallel operation management.
Key Technical Specifications
Insights from Woodward SPM-A series documentation and industrial supplier listings (e.g., GlobalSpec, Machinio) reveal the following parameters for the 9905-028:
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Input Voltage: 120 VAC RMS or 240 VAC RMS (supports both North American and international power standards).
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Frequency Range: 50 to 60 Hz (compatible with global grid frequencies).
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Synchronization Tolerances:
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Frequency: ±0.1 Hz (matches online system frequency).
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Phase Angle: ±10° (aligns generator phase with the online system).
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Voltage: 1–5% (adjusts generator voltage to match the online system).
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Output Options:
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Breaker Closure Signal: Dry contact (24 Vdc, 2A) to trigger circuit breaker closing.
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Status Indication: LED indicators for synchronization status (ready/not ready).
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Power Consumption: ≤8 W (low-power design for continuous operation).
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Operating Temperature: -20°C to +70°C (-4°F to +158°F) (suitable for indoor industrial environments).
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Mounting: Panel-mounted (fits standard 19-inch control cabinets).
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Certifications: CE, UL (compliant with international safety standards).
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Dimensions: ~250 mm × 180 mm × 80 mm (9.8in × 7.1in × 3.1in) – compact for space-constrained panels.
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Weight: ~3.5 kg (7.7 lbs) – lightweight for easy handling.
WOODWARD 9905-068
Field Application & Problem Solved
In industrial power systems, improper generator synchronization (e.g., frequency mismatch, phase misalignment) can lead to:
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Electrical Faults: Short circuits, voltage spikes, or equipment damage (e.g., generator windings).
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Grid Penalties: Fines for frequency deviations (e.g., >±0.5 Hz from 50/60 Hz).
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Downtime: Generator tripping, process interruptions, or delayed grid connection.
The 9905-028 addresses these challenges by:
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Automated Synchronization: Eliminates manual synchronization errors by continuously monitoring the online system’s frequency/phase and adjusting the offline generator’s speed via a control signal (e.g., to a Woodward 2301A governor).
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Tight Tolerance Control: Ensures frequency (±0.1 Hz) and phase (±10°) alignment, meeting stringent grid codes (e.g., NERC PRC-002).
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Seamless Breaker Closure: Sends a dry contact signal only when synchronization is achieved, preventing premature breaker closure and associated faults.
Typical Applications:
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Power Generation: Synchronizing standby diesel/gas generators to the utility grid during peak demand or outages.
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Marine Propulsion: Synchronizing shipboard generators for auxiliary power in parallel with the main grid.
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Industrial Cogeneration: Paralleling turbine-driven generators with grid power to balance electrical/thermal loads.
Installation & Maintenance Pitfalls (Expert Tips)
To ensure reliable synchronization with the 9905-028:
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Verify Input Voltage:
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Confirm the input voltage (120/240V AC) matches the module’s rating. Use a multimeter to check for voltage drops or surges, which can disrupt synchronization.
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Calibrate Speed/Frequency Sensors:
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Use a precision frequency meter to calibrate the generator’s speed sensor (e.g., magnetic pickup) before installation. Miscalibrated sensors cause persistent frequency mismatches.
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Test Synchronization Logic:
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After installation, simulate synchronization using a variable frequency drive (VFD) to adjust the generator’s speed. Verify the module sends a breaker closure signal only when frequency/phase/voltage are aligned.
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Regular Maintenance:
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Inspect the 9905-028 annually for loose connections, cracked casings, or corroded terminals. Clean the module with a dry cloth (avoid liquids near electrical components).
WOODWARD 9905-068
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Technical Deep Dive & Overview
The 9905-028 operates on Woodward’s SPM-A synchronization algorithm, a proven method for generator paralleling:
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Signal Reception:
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Measures the online system’s frequency, phase, and voltage via potential transformers (PTs) and current transformers (CTs).
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Comparison & Adjustment:
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Compares the offline generator’s parameters to the online system. If mismatched, it sends a control signal to the generator’s governor (e.g., Woodward 2301A) to adjust speed (frequency) or excitation (voltage).
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Phase Locking:
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Uses a phase-locked loop (PLL) circuit to align the generator’s phase with the online system once frequency/voltage are matched.
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Breaker Closure:
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When all parameters are within tolerance, the module energizes a dry contact to close the circuit breaker, paralleling the generator.
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Distinction from Similar Models:
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Unlike the 9905-002N (115/230V AC input, Rev. N firmware), the 9905-028 uses 120/240V AC input and is optimized for North American power standards.
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Integrates directly with Woodward 2301A load-sharing systems, whereas some SPM-A variants require additional interfaces.
Final Notes
The Woodward 9905-028 is a critical component for ensuring safe, reliable generator synchronization in industrial power systems. Its automated control, tight tolerance alignment, and seamless integration with Woodward’s ecosystem make it ideal for applications where grid compliance and uptime are non-negotiable.
When installing or maintaining the 9905-028, always adhere to Woodward’s SPM-A Series Synchronizer Manual (Document # SPM-A-OM-001) and consult a certified technician. For applications requiring extended temperature ranges or hazardous-area compliance, consider Woodward’s enhanced SPM-A variants (e.g., 9905-001-G for arctic environments).
