ABB RET620E-1G NBTNAANNNBA1BNN11G
The ABB RET620E-1G NBTNAANNNBA1BNN11G is a transformer protection relay under the ABB Relion® 620 series, specifically designed for the comprehensive protection of medium and low voltage distribution transformers (such as double-winding, three-winding, and grounding transformers). This relay provides differential protection, backup protection, and non-electrical quantity protection, ensuring the safe operation of transformers under abnormal conditions like overload, short circuit, and ground fault. It is suitable for substations, industrial power distribution, and renewable energy sectors.
Core Values of RET620E-1G
High-precision differential protection: Adopts harmonic restraint and proportional restraint algorithms to avoid misoperation caused by inrush current.
Multi-function integration: Integrates backup functions such as overcurrent protection, ground fault protection, and temperature protection, reducing the need for external equipment.
Advanced communication: Supports IEC 61850, Modbus TCP/IP, and DNP3.0, enabling seamless integration into smart grids.
Product Parameters
Product Model: RET620E-1G NBTNAANNNBA1BNN11G
Manufacturer: ABB
Product Type: Transformer protection relay
Rated Current: 1A or 5A (CT secondary side, configurable)
Differential Pickup Value: 0.2-1.0Ie (step size 0.01Ie)
Restraint Coefficient: 0.1-0.8 (adjustable slope)
Harmonic Restraint: 2nd harmonic (15-30% adjustable), 5th harmonic (optional)
Operating Time: ≤25ms (internal fault)
Communication Protocols: IEC 61850, Modbus TCP, DNP3.0
Input/Output: 12× digital inputs, 8× relay outputs
Operating Temperature Range: -25°C to +55°C (-13°F to +131°F)
Protection Class: IP40 (panel mounting)
Mounting Method: DIN Rail or panel mounting
Certification Standards: IEC 60255, IEEE C37.90, UL 508
Structure and Composition
The RET620E-1G adopts a modular design, with main components including:
Signal Acquisition Unit
High-precision CT/PT interfaces, supporting multi-side current input (e.g., high-voltage side, low-voltage side, neutral point).
DSP Processing Module
Real-time calculation of differential current and restraint current, and execution of proportional restraint and harmonic analysis.
Protection Logic Unit
Programmable protection curves (e.g., IEEE Std C37.91).
Communication Interface Board
Dual Ethernet ports (for IEC 61850), RS-485 (for Modbus RTU).
Human-Machine Interface (HMI)
320×240 graphic LCD for local viewing of differential current, harmonic content, and event records.
Non-Electrical Quantity Protection Interface
Supports direct access to non-electrical quantity signals such as gas relays and temperature sensors.
Application Fields
The RET620E-1G is mainly used in the following scenarios:
Power Substations
Main protection (differential + backup protection) for 10kV/35kV distribution transformers.
Industrial Power Distribution
Protection for auxiliary transformers (e.g., in mining, petrochemical enterprises).
Renewable Energy
Protection for step-up transformers in wind farms/photovoltaic power plants.
Typical Application Case
In a 35kV substation, the RET620E-1G serves as the main transformer differential protection. It uploads operation information to the SCADA system via Modbus TCP, trips within 20ms in case of winding short circuit, and avoids misoperation caused by no-load inrush current through 2nd harmonic restraint.
Installation and Maintenance
Installation Key Points
Use shielded wires of ≥2.5mm² for CT secondary wires to avoid induced voltage interference.
The polarity of multi-side CTs must be consistent (pointing to the transformer).
Maintenance Recommendations
Conduct a proportional restraint characteristic test (using the CMC256 tester) once a year.
Regularly check the software version and upgrade it via PCM600.
Xingruijia focuses on providing ABB industrial automation full range product services and your intelligent control solution partner
If you would like to learn more about our products and services, please feel free to contact us at any time!
Sales Manager : Jinny
Email : sales1@xrjdcs.com
Whatsapp/Mobile:+86 15359273791
Switzerland 
.jpg)
.jpg)
