Beckwith Electric M3420 Generator Protection Relay
The Beckwith Electric M3420 is a fully integrated, microprocessor-based generator protection relay designed to protect synchronous generators of all sizes. It provides a comprehensive suite of protection functions, including differential, overcurrent, over/undervoltage, over/underfrequency, reverse power, loss-of-excitation, and more. The M3420 also offers advanced metering, fault recording, and communication capabilities, making it a versatile solution for both utility and industrial generator applications.
This relay is built with a modular architecture, allowing flexible I/O configuration and easy upgrades. Its high-speed processing and accurate measurements ensure fast and reliable fault detection, minimizing damage and improving system stability.
Key Features
Protection functions: 87G, 51V, 27, 59, 81, 32, 40, 46, 49, 50, 51, and more
High accuracy: ±0.5% for voltage and current
Dual Ethernet ports (Modbus TCP, DNP3, IEC 61850)
Sequential events recorder (SER) with 1024 events
Fault recorder with oscillography
Programmable logic (FlexLogic™)
Large graphic display with intuitive menus
Technical Specifications
Inputs: 1A/5A CT, 100–480 VAC PT; frequency: 50/60 Hz; power supply: 24–250 VDC or 120/240 VAC; output relays: up to 16 programmable; operating temperature: -20°C to +70°C; enclosure: IP40.
Applications
Ideal for prime power generators, standby sets, co-generation plants, and renewable energy systems. The M3420 is used in both new installations and retrofits, providing primary and backup protection for generators in critical applications.
Installation and Configuration
Mount the relay in a standard panel or rack. Connect CTs, PTs, and control wiring. Configuration is performed via the front panel or PC-based software (BESTCOMS™). The relay includes auto-configuration wizards to simplify setup.
Reliability and Maintenance
Designed with redundant power supplies and self-diagnostics, the M3420 ensures high availability. Firmware upgrades are field-upgradeable. Regular testing using secondary injection is recommended.
Why Choose the M3420?
This relay offers a perfect balance of protection performance and flexibility. Its modular design, extensive communication options, and Beckwith’s reputation for quality make it a top choice for generator protection.
In summary, the Beckwith Electric M3420 provides complete, reliable protection for generators, ensuring safe and stable operation in all conditions.
