Choosing a sophisticated device like the ABB NBRA-659C is a significant decision. Its successful implementation—from the initial specification to final commissioning—requires careful planning and expert execution. This guide is designed for project engineers, system integrators, and maintenance managers, providing a roadmap for the selection, configuration, and procurement process to ensure optimal performance and reliability.
Phase 1: Specification and Feasibility
Before issuing a purchase order, confirm the NBRA-659C is the right tool for the job. Start with a clear specification.
- Define the Protection Requirements: List all required functions. Do you need overcurrent, earth-fault, voltage, frequency, or directional protection? What are the primary and backup roles of the relay?
- Review System Parameters: Gather the key data:
- System Voltage: The relay must be rated for your nominal and maximum voltage.
- Fault Current Levels: Know the maximum three-phase and earth-fault currents at the installation point. The relay's current inputs must handle these via appropriate Current Transformers (CTs).
- CT and VT Ratios: The relay must be compatible with the existing instrument transformer ratios.
- Assess Communication Needs: Determine the integration strategy. Is this a legacy retrofit requiring DNP3 serial communication, or a new digital substation using IEC 61850 over Ethernet? Ensure the specific NBRA-659C variant ordered supports the required protocols and physical ports (fiber, copper).
- Physical and Environmental Fit: Verify the device's dimensions and mounting style are compatible with your panel layout. Confirm its operating temperature range suits the substation environment.
Phase 2: Configuration and Engineering
Once the hardware is selected, the real engineering begins. This is where the relay is tailored to your specific application.
- Protection Setting Calculations: This is critical. Using system studies (load flow, short-circuit), calculate the precise settings for each protection function. This includes:
- Pickup Values: The current/voltage level at which the relay should start operating.
- Time-Curve Selection: Choosing the correct inverse-time curve (e.g., IEC Standard Inverse, Very Inverse) and time multiplier settings to ensure proper coordination with adjacent protective devices. A mis-coordinated setting can cause a minor fault to trigger a widespread outage.
- Software Configuration: Using ABB's engineering software (like PCM600):
- Connect to the relay via its service port.
- Upload the default configuration or a previous template.
- Input all the calculated settings into the appropriate parameter groups.
- Configure the Programmable Scheme Logic (PSL). This is where you build custom automation sequences. For example, create logic to auto-transfer a busbar section or to block reclosing under certain conditions.
- Map the I/O points (binary inputs for breaker status, outputs for trip/close) and configure communication datasets for SCADA.
- Documentation: Meticulously document all settings, logic diagrams, and communication maps. This "as-built" documentation is invaluable for future troubleshooting and modifications.
Phase 3: Procurement and Sourcing Strategy
With specifications and settings ready, sourcing the device correctly is paramount.
- Authorized Channels are Non-Negotiable: Always purchase the NBRA-659C from authorized ABB distributors or directly from ABB. The market for obsolete or counterfeit protection relays is risky. A fake relay may fail to operate during a fault, with catastrophic consequences.
- Provide the Complete Reference: The ordering code NBRA-659C is a base model. You must specify the complete hardware and software options. This includes:
- Auxiliary Supply Voltage: (e.g., 48-110V DC, 110-240V AC/DC).
- Communication Modules: The exact type of front or rear communication boards needed (Ethernet, fiber, serial).
- Firmware Version: Specify the required firmware version compatible with your engineering tools and system protocols.
- Consider Lifecycle and Support: Check the product's lifecycle status on ABB's official website. Understand the warranty, lead times, and long-term support availability. For critical spares, it's wise to purchase a spare unit concurrently.
Phase 4: Installation and Commissioning
The final step validates the entire process.
- Primary Injection Testing: This is the most important test. Using a test set, inject realistic current and voltage signals into the relay's CT and VT circuits to simulate faults. Verify that the relay picks up and trips at the exact specified settings and times.
- Functional Testing: Test all binary inputs (breaker status, external alarms) and outputs (trip/close commands, alarm relays).
- Communication Verification: Confirm that the SCADA system correctly reads all measured values and statuses, and can execute control commands.
Conclusion
Successfully deploying the ABB NBRA-659C is a multi-stage journey that blends electrical engineering, software configuration, and diligent procurement. Skipping steps or cutting corners in specification, setting calculation, or sourcing can compromise an entire protection scheme. By following this structured approach—from rigorous needs analysis and precise engineering to sourcing from authorized partners and thorough testing—you ensure this powerful device delivers its full potential: unwavering protection and intelligent control for your electrical assets.
