The Woodward 9905-708, also cataloged as the 9905-708 Digital Synchronizer and Load Control Module, operates as a dedicated hardware component for automatic generator phase matching and real/reactive power load distribution within DSLC power management platforms.

Hardware Specifications

Thermal Heat Sink Dissipation & Harmonic Distortion Suppression

Power conversion and digital processing circuits inside the compact enclosure dissipate internal heat via conduction through the aluminum baseplate. Effective thermal heat sink dissipation ensures operational stability and prevents thermal calibration drift across wide ambient fluctuations. The module continuously calculates phase angle error, slip frequency, and bus voltage differentials, driving rapid actuator loop feedback response to governor speed loops and automatic voltage regulators (AVRs) while mitigating harmonic distortion transients during parallel breaker closing.

Frequently Asked Questions

• Q: What cable topology is recommended for the 4-20 mA and digital speed/voltage bias outputs?
• A: Output control signals to speed governors and automatic voltage regulators must use twisted-shielded pair conductors, with the shield drain wire connected at a single chassis ground point.
• Q: How should potential transformer (PT) voltage inputs be wired to prevent noise coupling?
• A: Bus and generator PT sense lines must pass through dedicated fused isolation transformers and be routed in separate conduits away from high-current AC power leads.
• Q: What mounting orientation supports optimum thermal performance and mechanical stability?
• A: The unit should be mounted vertically on a flat, unpainted metal backplate to maximize heat dissipation surface contact and structural rigidity against panel vibration.

Field Installation Guidelines

• Secure the module to the enclosure mounting plate using all four mounting points to guarantee structural stability.
• Ensure a low-impedance bonding strap connects the module frame ground terminal directly to the main switchgear earth bus.
• Route low-voltage DC power supply lines and communication cables in dedicated grounded channels isolated from high-voltage potential transformer circuits.
• Confirm correct voltage transformer ratios and phase sequencing on generator and bus inputs prior to energizing the control supply.