ABB SPAU140C

Technical Specifications
Based on official ABB documentation and technical archives, the core specifications include:

• Product Type: Numerical Synchro-Check Relay
• Series: SPA Series (Legacy/Classic)
• Rated Frequency: 50 Hz / 60 Hz
• Rated Voltage:
  • Measuring voltage: 100V, 110V (secondary)
  • Auxiliary supply (U aux): 80…265V AC/DC or 18…80V DC
• Measurement Accuracy:
  • Voltage: ±0.2% of full scale (16-bit ADC)
  • Frequency: ±0.005 Hz
• Response Time:
  • Synchronization detection cycle: ≤ 20 ms
  • Closing command output delay: ≤ 10 ms
• Operating Modes: Continuous mode and Command mode
• Communication Interface:
  • Standard: RS-485 (Modbus RTU protocol)
  • Optional: IEC 61850 (Ethernet)
  • System Bus: Serial interface for SPA bus connection
• Protection Features: Continuous auto-diagnostic self-supervision (hardware and software)
• Display: Numerical display for settings, measured values (U1/Un, U2/Un, ∆ϕ, ∆f), and fault records
• Environmental Compliance: CE marking, IEC 60255, EMC Directive compliance
• Mounting: Typically panel-mounted or DIN-rail mounted within control cabinets

Functional Features

• Dual-Stage Operation: The relay features two identical operation stages, allowing it to independently check the closing conditions for two separate circuit breakers. This makes it suitable for duplex switchgear or complex busbar configurations.
• Synchro-Check Function: This primary function permits circuit breaker closing only if the voltages on both sides meet preset conditions regarding magnitude (typically ≤5% difference), phase angle (typically ≤10°), and frequency (typically ≤0.2 Hz difference).
• Voltage-Check Function: Used when connecting a de-energized bus or line to an energized section. It verifies that the incoming voltage is within a permissible range (e.g., 80% to 110% of nominal) to prevent energizing a faulted line.
• Slip Lock (Slip Blocking): Automatically blocks the closing command if the frequency difference (slip) between the two systems exceeds a set threshold, preventing closure during unstable conditions.
• Programmable Synchronization Window: Users can adjust the tolerance thresholds for voltage, phase, and frequency to adapt to specific grid conditions or generator characteristics.
• Breaker Failure Protection: Includes logic to detect if a breaker fails to operate after a command is issued.
• Data Recording & Analysis: Capable of recording fault events, measured values at the time of operation, and oscillography data for post-event analysis.
• Independent Outputs: Provides separate relay outputs for closing command (CB13, CB23) and signaling (NC13, NC23), allowing for flexible integration with external control schemes.
• Self-Supervision: Continuously monitors internal hardware (CPU, memory, ADC) and auxiliary supply voltages. If a fault is detected, it triggers an alarm and blocks the output relays to ensure fail-safe operation.

Application Scenarios
The ABB SPAU140C is deployed in high-stakes environments where precise synchronization is mandatory:

• Power Generation: Synchronizing generator output with the grid or with other generators in a power plant (hydroelectric, thermal, nuclear).
• Transmission & Distribution:
  • Connecting two separate electrical networks or grid sections (ring main units).
  • Busbar coupling in substations.
  • Transformer supervision and synchronization.
• Industrial Process:
  • Large motor start-up where synchronization with the grid is critical.
  • Backup power supply transfer (e.g., diesel generator to main grid).
• Renewable Energy: Grid connection of wind farms and solar power plants, ensuring smooth synchronization with the utility grid to prevent instability.
• Heavy Industry: Steel mills, chemical plants, and petrochemical facilities where process continuity depends on reliable power synchronization.
• Railway & Marine: Traction power supply systems and shipboard power management systems requiring redundant power sources.

Market Information and Availability

• Product Status: Legacy / Non-Active. ABB officially lists this product as “Not active product since 2012.” However, it remains a high-demand spare part for maintaining existing infrastructure.
• Supply Chain: Widely available through third-party industrial automation distributors, particularly in China, Europe, and North America. It is often stocked by specialized suppliers of ABB protection relays.
• Pricing: Prices vary based on condition (new, refurbished) and origin. Listings from 2026 indicate prices ranging from 5,800 RMB to 7,000 RMB per unit.
• Packaging: Typically shipped in original ABB packaging with anti-static protection.
• Warranty: Most suppliers offer a one-year warranty for refurbished or surplus units.