ABB SPAJ110C Earth-Fault Relay

Technical Specifications

• Power Supply: 24 VDC or 230 VAC
• Rated Current: 1 A (adjustable via current transformers)
• Earth-Fault Current Range: 30 mA to 2 A
• Response Time: ≤20 ms
• Time Reset: ≤0.5 s
• Relay Contacts: 1 single-pole double-throw (SPDT) contact
• Communication Interface: RS-485 for integration with substation control systems
• Dimensions: 72 mm x 36 mm x 22 mm
• Weight: 0.2 kg
• Operating Temperature: -20°C to 55°C
• Storage Temperature: -40°C to 85°C
• Humidity: 5% to 95% (non-condensing)
• Vibration Resistance: 5 g (10 Hz to 500 Hz)
• Certifications: CE, UL, and compliant with IEC 61850 and other international standards

Key Features

• Dual Protection Stages:
  • Low-Set Stage (I0>): Configurable with definite-time or inverse-time characteristics for sensitive earth-fault detection.
  • High-Set Stage (I0>>): Operates with definite-time characteristics for rapid response to severe faults.
• Flexible Configuration: Output relay functions can be freely programmed to suit specific application requirements.
• Serial Interface: Enables connection to fiber-optic object buses and substation control systems for remote monitoring and control.
• Digital Display: Provides real-time visualization of setting values, measured neutral current, and stored fault data for diagnostics.
• Self-Supervision: Continuously monitors hardware and software health, with auto-diagnostics to alert users of potential issues.
• Robust Design: Built to withstand harsh industrial environments with high vibration resistance and wide temperature tolerance.

Functional Characteristics

• Earth-Fault Detection: Measures residual current via three-phase current transformers or a window-type core-balance current transformer.
• Alarm and Trip Functions: Issues alarms or trips circuit breakers based on configured thresholds and time delays.
• Cooperation with Residual Voltage Relays: Can be configured to work with residual voltage relays for enhanced protection coordination.
• Data Logging: Records fault events and operational data for post-analysis and troubleshooting.
• Modular Design: Facilitates easy integration into existing protection schemes with minimal downtime during installation or maintenance.

Application Scenarios

• Power Generation: Used in thermal, hydro, and nuclear power plants to protect generators and transformers against earth faults.
• Industrial Automation: Ensures reliable operation of motors and feeders in manufacturing, mining, and oil & gas industries.
• Renewable Energy: Integrates into wind turbine and solar inverter control systems for grid stability and safety.
• Marine Applications: Provides earth-fault protection for shipboard generators and propulsion systems in harsh marine environments.
• Utility Distribution: Safeguards medium-voltage feeders and transformers in electrical substations and distribution networks.
• Critical Infrastructure: Protects equipment in hospitals, data centers, and airports where power continuity is essential.