GE Multilin B90-B9M-15C Bus Differential Protection Relay

Product Overview

The B90-B9M-15C is a GE Multilin B90 series bus differential protection relay designed for fast, secure protection of medium-, high-, and extra-high-voltage busbar systems. As part of the UR Family, it combines low-impedance bus differential protection with integrated breaker failure logic, supporting both simple and highly complex multi-section busbar schemes.

The B90-B9M-15C is engineered for centralized protection architectures and can operate as a standalone relay or as part of a multi-relay system. It delivers sub-cycle fault clearing with a typical tripping time of 0.75 cycles, minimizing fault impact and improving overall system stability.

Functional Description

The B90-B9M-15C uses low-impedance differential algorithms to detect internal busbar faults with high sensitivity and security. The relay supports up to 24 feeders and multiple differential zones per phase, allowing flexible configuration for single, double, or multi-section busbars.

Advanced CT saturation detection ensures stable operation during external faults, even with heavily saturated current transformers. Integrated breaker failure protection enables coordinated isolation of failed breakers, reducing fault escalation and system damage.

The relay supports modern substation automation through IEC 61850 and other industry-standard communication protocols, making it suitable for both new installations and retrofit projects.

Technical Specifications

• Model / Part Number: B90-B9M-15C

• Manufacturer: GE Multilin (GE Vernova Grid Solutions)

• Product Type: Bus Differential Protection Relay

• Protection Principle: Low-impedance bus differential

• Tripping Time: 0.75 cycles (sub-cycle)

• Differential Zones: Up to 6 zones per phase

• Feeder Capacity: Up to 24 feeders

• Breaker Failure Protection: Integrated

• CT Saturation Detection: Operates with as little as 2 ms saturation-free current

• Event & Disturbance Recording: High-resolution waveform capture

• Self-Diagnostics: Continuous hardware and software monitoring

• Communication Protocols: IEC 61850, Modbus, DNP3, IEEE C37.94

• Operating Temperature: –40 °C to +85 °C

• Mounting: Rack-mounted relay chassis

• Weight: 5 kg