Description
Key Technical Specifications
| Parameter | Value |
|---|---|
| Manufacturer | ABB |
| Product Line | RELION 670 Series (IEC 61850 IED) |
| Module Type | Transformer Protection Relay |
| Part Number | 1MRK004816-AC |
| Main Protection | Low-Impedance & High-Impedance Differential |
| Backup Protection | Distance, Positive/Negative/Zero Sequence Overcurrent |
| Communication | IEC 61850-9-2LE Process Bus (up to 6 Merging Units) |
| Harmonic Blocking | 2nd (Inrush) and 5th (Over-excitation) |
| Binary Inputs | High-immunity, anti-interference design |
| Advanced Logic | Graphical User Logic, Pole Slip Detection |
| Mounting | Rack / Panel Mount |
Product Introduction
Substation engineers know that transformer inrush currents and CT saturation are the two most common causes of nuisance tripping in differential protection schemes. The ABB RET670 1MRK004816-AC was built specifically to solve this. It serves as the primary intelligent electronic device (IED) for high-voltage transformers, utilizing advanced waveform blocking and harmonic suppression to distinguish between genuine internal faults and transient startup conditions.
We stock the ABB RET670 1MRK004816-AC because grid operators need immediate replacements for 220kV-500kV applications without waiting months for factory builds. This relay supports the IEC 61850-9-2LE process bus, allowing it to interface directly with up to six merging units for synchronized sampled values. It’s a heavy-duty piece of gear. Just remember: configuring the graphical user logic for pole slip detection requires a solid understanding of power system stability, not just relay settings.
QA/QC Transparency SOP
- Intake & Origin Verification: We trace the ABB RET670 1MRK004816-AC back to its decommissioned site or surplus lot. Visual inspection checks for damaged fiber optic ports, bent binary input terminals, and physical damage to the front panel display.
- Live Functional Testing: The relay goes on a dedicated test bench. We inject simulated differential currents and verify the trip logic activates within the sub-10ms spec. No “blink test” here; it must actually execute protection functions.
- Electrical Parameter Tests: Using a Fluke 115 and relay test set, we check isolation resistance between analog inputs, binary inputs, and the chassis. Power supply ripple is measured under full load.
- Firmware/Config Verification: We read the onboard memory to confirm the firmware revision and software package (e.g., A30, B40) matches the 1MRK004816-AC label. Configuration files are backed up and verified.
- Final QC & Anti-Static Packaging: After passing, it gets a test sheet, anti-static bag, and desiccant. If it fails any injection test, it’s quarantined. No “as-is” sales on critical protection gear.
Field Engineer Gotchas
- Software Package Mismatch: The ABB RET670 1MRK004816-AC comes in different software packages (e.g., A30 for single-breaker two-winding, B40 for multi-breaker three-winding). Risk: Missing protection functions after installation. Fix: Always verify the software package on the front label matches your application. I’ve seen a tech install a B40 relay on a simple two-winding setup and spend hours trying to find the missing non-existent three-winding config.
- IEC 61850-9-2LE Configuration: This relay supports process bus, but the SV (Sampled Values) configuration is complex. Risk: Communication failures with merging units. Fix: Verify the MAC addresses, APPID, and SCL/SCD file matches exactly. A single bit mismatch in the SCD file will cause the relay to block SV inputs.
- Binary Input Interference: The binary inputs are high-immunity, but they aren’t magic. Risk: False trips from DC system ground faults or capacitor discharge. Fix: Ensure proper shielding and grounding of binary input wiring. I’ve seen a relay trip because someone ran an unshielded binary wire parallel to a DC solenoid cable.
- CT Saturation Settings: The differential protection has low CT requirements, but settings still matter. Risk: Failure to block during external faults. Fix: Verify the CT dimensioning and saturation voltage settings in the relay configuration. The 2nd harmonic blocking must be tuned to your specific transformer’s inrush characteristics.
ABB RET670 1MRK004816-AC
Application Scenarios
- High-Voltage Substations: Primary protection for 220kV-500kV power transformers in grid transmission networks.
- Power Generation Plants: Generator step-up (GSU) transformer protection with fast differential and backup distance functions.
- Industrial Power Systems: Protecting large three-winding autotransformers in steel mills and chemical plants.
- Case Study: A regional substation experienced repeated nuisance trips on a 345kV transformer during energization. The existing relay couldn’t distinguish the inrush from a fault. We replaced it with an ABB RET670 1MRK004816-AC, configured the 2nd harmonic waveform blocking, and the transformer has been stable for 3 years. The old relay was sent for refurbishment. Bottom line — harmonic blocking saves transformers.
FAQ
Is the RET670 1MRK004816-AC suitable for generator protection?
No. The is specifically designed for transformers. For generator protection, you need the REG670. Different algorithms, different protection functions.
Does this support IEC 61850 GOOSE messaging?
Yes. The supports both GOOSE and SV (Sampled Values) over IEC 61850-9-2LE. Verify your network architecture supports process bus before specifying.
Why is my differential relay blocking during a real fault?
Check the harmonic blocking settings. If the 2nd harmonic threshold is set too low, it may block during internal faults with CT saturation. Also verify the waveform blocking logic. The has multiple blocking algorithms; make sure you’re using the right one for your application.
Can I hot-swap this relay?
No. Protection relays are not hot-swappable. Pulling the while energized will leave the transformer unprotected. Plan a complete outage and isolate the transformer first.
How do I configure the graphical user logic?
Use ABB’s Configuration Tool for RELION. The supports drag-and-drop logic blocks, but you need to understand the underlying protection philosophy. Don’t just copy logic from another project without verifying it applies to your system.
Is this compatible with legacy IEC 60870-5-103 systems?
Yes, but verify the communication mapping. The primarily uses IEC 61850, but can support legacy protocols via gateway or configured mapping. Check the technical manual for supported profiles.
How do I know if it’s truly tested?
Ask for the test report. If the seller can’t show you an injection test log, harmonic blocking verification, or communication test result, walk away. Protection relays are safety-critical. “Tested” is a marketing word; data is engineering.
