Description
Woodward 8444-1093
Technical Specifications
- Product Type: Synchronizing Relay / Check Relay.
- Voltage Rating: Compatible with standard generator and bus PT secondary voltages.
- Contact Rating: Rated for control circuit switching.
- Function: Phase angle and voltage differential checking.
Functional Features
- Precision Checking: Accurately detects when the generator and bus are within acceptable synchronization windows.
- Interlocking: Prevents out-of-phase closing of the generator breaker, protecting equipment from catastrophic damage.
- Fast Response: Minimal operate time to allow for precise breaker closing at the exact zero-crossing point.
- Robust Construction: Designed to withstand continuous electrical stress and mechanical vibration.
Application Scenarios
Essential in any power generation facility where generators must be safely synchronized to a grid or another generator, including power plants, marine vessels, and backup power systems.
Performance Parameters
- Phase Angle Window: Typically adjustable or fixed at a precise degree (e.g., ±5 degrees).
- Voltage Differential Window: Accurate detection of voltage mismatch (e.g., ±2%).
- Operate Time: Millisecond-level response for precise synchronization.
Material Composition
Features high-quality electrical contacts and a durable coil assembly (if electromechanical) or solid-state switching elements. Housed in a protective case to prevent dust and moisture ingress.
Structural Characteristics
Compact relay form factor with standard screw terminals or plug-in connections. Clear labeling for coil and contact terminals.
Working Principle
Continuously monitors the voltage waveforms of the incoming generator and the running bus. When the phase angle difference, frequency difference, and voltage magnitude difference all fall within preset safe limits, the relay energizes its output contacts to permit the synchronizing breaker to close.
Installation Requirements
Wire according to the synchronizing system schematic. Ensure PT circuits are properly fused and grounded. Mount in a location free from excessive vibration.
Usage Precautions
- Never bypass the synchronizing check relay.
- Periodically test the relay’s operate points to ensure calibration.
- Verify that the relay’s voltage rating matches the system PT secondary voltage.
