Crompton 256-PAS Protector Trip Relay

The Crompton Instruments 256-PAS, also cataloged as the 256-PAS Power Relay, operates as a dedicated hardware component for reverse power protection within AC generator networks. It measures directional real power flow natively at the electrical tier to execute protective trip functions parallel to master control network platforms when synchronized assets experience motoring conditions.

Hardware Specifications

Industrial Control & Drive Integration

• Backplane Bus Communication Velocity Licences and Relay Interlocking: The standalone protective module interfaces with generator breaker trip circuits via heavy-duty electro-mechanical contact blocks. It executes safety-critical trip curves locally, isolating the prime mover without relying on external backplane bus communication velocity data packets or secondary automation processor intervention.
• Profinet / EtherNet/IP Deterministic Networks Fault Tracking: Auxiliary contacts on the output circuit pass physical open/closed state telemetry to intermediate RTUs or PLC input lines. This design provides real-time fault mapping across Profinet / EtherNet/IP deterministic networks to log reverse-power sequence events on supervisory SCADA consoles.
• I/O Density Scaling and Local Control Topology: Integrating the absolute current transformation and timing circuitry into a self-contained unit optimizes standard panel I/O density scaling. The local processing layout eliminates the need for high-speed analog processing modules inside the main control rack by handling true power vectors directly at the point of measurement.

Frequently Asked Questions

Q: What technical behaviors manifest within the internal measurement loop if the prime mover fails and the generator begins motoring?

A: The voltage and current phase alignment shifts past 90 degrees, signaling a reversal of real power flow into the stator. Once the negative magnitude surpasses the calibrated 2% to 20% dial setpoint, the internal timing circuit starts down, firing the 5 A output contacts after the set delay window closes.

Q: Can this protective relay be mounted directly on surfaces subject to severe mechanical displacement inside engine skids?

A: No. High mechanical shock or vibration can cause the internal electro-mechanical contact points to chatter, leading to false trips or contact degradation. The module must be snapped onto a secure 35 mm DIN rail or bolted to a rigid enclosure wall away from direct engine displacement paths.