SIEMENS 7UT6125-5EB20-1AA0/BB Differential Protection Relay – SIPROTEC 7UT612 Series
When a transformer, motor, or generator loses its differential protection, the consequences are catastrophic: undetected internal faults escalate within milliseconds into full-scale equipment failures, causing unplanned shutdowns, costly repairs, and — in the worst cases — fires or explosions that endanger personnel and infrastructure. In critical power distribution environments, every second without reliable protection is a second of unacceptable risk.
The SIEMENS 7UT6125-5EB20-1AA0/BB is a high-performance numerical differential protection relay from the renowned SIPROTEC 7UT612 series, engineered specifically for the protection of transformers, motors, generators, and busbars in medium- and high-voltage power systems. As part of Siemens’ globally trusted SIPROTEC 4 platform, this relay delivers sub-cycle fault detection, advanced harmonic restraint, and seamless integration into modern SCADA and substation automation architectures — making it a cornerstone component in power utilities, heavy industry, and critical infrastructure worldwide.
Technical Specifications
- Model / Part Number: 7UT6125-5EB20-1AA0/BB
- Series: SIPROTEC 7UT612
- Manufacturer: SIEMENS AG
- Function: Numerical Differential Protection Relay
- Protected Objects: Transformers, Motors, Generators, Busbars
- Rated Frequency: 50/60 Hz
- Auxiliary Voltage: 110–125 V DC (as per variant code -5EB20)
- Communication Interface: IEC 61850 / PROFIBUS / RS-485 (variant dependent)
- Mounting: Flush panel / rack mounting
- Weight: Approx. 4.46 kg
- Standards Compliance: IEC 60255, IEC 61850, CE
Note: All specifications are based on Siemens official documentation. Contact us to verify exact variant parameters before ordering.
Key Features & Benefits
- High-Speed Differential Protection: Sub-cycle tripping for internal faults, minimizing equipment damage and downtime.
- Advanced Harmonic Restraint: 2nd and 5th harmonic blocking prevents false trips during transformer energization (inrush current).
- Flexible CT Ratio Matching: Software-configurable current transformer ratio compensation eliminates the need for interposing CTs.
- Integrated Overcurrent Backup: Built-in overcurrent and earth-fault protection functions provide comprehensive backup coverage.
- IEC 61850 Ready: Native support for modern substation communication protocols enables seamless SCADA integration.
- Comprehensive Event Recording: Fault records, disturbance recordings, and event logs support rapid post-fault analysis.
- User-Friendly Parameterization: DIGSI 4 software interface simplifies configuration, testing, and commissioning.
Industry & Equipment Applications
- Power Utilities & Substations: Protection of power transformers in transmission and distribution substations.
- Oil & Gas: Motor and generator protection in upstream/downstream processing facilities.
- Steel & Metallurgy: Large drive motor protection in rolling mills and arc furnace installations.
- Water Treatment & Pumping Stations: Pump motor protection in critical water infrastructure.
- Renewable Energy: Generator protection in wind and solar power plants.
- Marine & Offshore: Shipboard power system protection and offshore platform electrical systems.
- Data Centers & Critical Facilities: UPS transformer and generator protection for uninterrupted power supply.
System Integration & Compatible Parts
The 7UT6125-5EB20-1AA0/BB integrates seamlessly within the Siemens SIPROTEC 4 ecosystem and broader substation automation environments. Compatible and commonly paired components include:
- SIPROTEC 7SJ61 / 7SJ62 / 7SJ64 — Overcurrent and motor protection relays for backup coordination
- SIPROTEC 7SD52 / 7SD61 — Line differential protection relays for feeder protection
- SIPROTEC 7VK61 — Busbar protection relay
- DIGSI 4 Software — Configuration and parameterization tool (PC-based)
- SIEMENS SICAM / SINAUT — Substation automation and SCADA communication systems
- Siemens SIRIUS 3RT / 3RV — Motor starters and circuit breakers for complete motor protection schemes
Our Quality Assurance Process
At Konmask.com, every SIEMENS relay we supply undergoes a rigorous multi-stage quality verification process before shipment:
- Authenticity Verification: Cross-referenced against Siemens official part databases and holographic label inspection.
- Visual & Physical Inspection: Full exterior inspection for damage, corrosion, and completeness of terminals and accessories.
- Functional Pre-Check: Where applicable, basic power-on and communication interface verification.
- Secure Packaging: Anti-static, shock-resistant packaging with humidity indicators for safe international transit.
- Documentation: Shipment accompanied by product datasheet, test records, and certificate of conformity upon request.
How to Order
- Submit an Inquiry: Contact us via email at [email protected] or call +0086 19859288691 with your required quantity and delivery timeline.
- Receive a Quote: Our technical sales team will provide a competitive quotation within 24 business hours.
- Order Confirmation: Confirm your purchase order; we verify stock availability and lead time.
- Shipment & Tracking: We arrange international freight (DHL / FedEx / sea freight) with full tracking and customs documentation support.
- After-Sales Support: Our engineering team is available for installation guidance and technical consultation post-delivery.
Why Choose Konmask.com?
- ✅ Specialized in Industrial Automation: Focused exclusively on PLC, DCS, drives, and protection relay components from leading global brands.
- ✅ Genuine Parts Guaranteed: We source directly from authorized channels and verified distributors — no counterfeits.
- ✅ Global Shipping Expertise: Experienced in export compliance, customs documentation, and international logistics to 50+ countries.
- ✅ Technical Support: Our team includes qualified automation engineers who can assist with compatibility and application questions.
- ✅ Competitive Lead Times: Extensive inventory network enables fast fulfillment even for hard-to-find or obsolete parts.
- ✅ B2B Focused: Tailored service for OEMs, system integrators, EPCs, and maintenance teams.
Frequently Asked Questions
Q: Is the 7UT6125-5EB20-1AA0/BB a new or refurbished unit?
A: We supply both new original and professionally refurbished units depending on availability. All units are clearly labeled and priced accordingly. Please specify your preference when inquiring.
Q: What is the difference between 7UT6125 and 7UT6126?
A: The 7UT6125 and 7UT6126 are variants within the SIPROTEC 7UT612 family, differing primarily in the number of current transformer inputs and protection object configurations. The 7UT6125 is optimized for 2-winding transformer and motor/generator protection, while the 7UT6126 supports 3-winding transformer applications.
Q: Can this relay communicate via IEC 61850?
A: Yes, the SIPROTEC 7UT612 series supports IEC 61850 Edition 1 communication. Specific interface availability depends on the ordered variant. Please confirm your communication requirements when placing an inquiry.
Q: What software is required to configure this relay?
A: The 7UT6125-5EB20-1AA0/BB is configured using Siemens DIGSI 4 software, which runs on Windows-based PCs. We can advise on software version compatibility upon request.
Q: Do you provide a warranty?
A: Yes. We offer a standard 12-month warranty against manufacturing defects on all new units. Refurbished units carry a 6-month warranty. Terms and conditions apply — please contact us for details.
Q: Can you supply other SIPROTEC relay models?
A: Absolutely. Konmask.com maintains an extensive catalog of SIEMENS SIPROTEC 4 and SIPROTEC 5 series relays. Contact us with your specific model requirements.
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