Beckwith Electric M3425A‑STD1 Generator Protection Relay

The Beckwith Electric M3425A‑STD1 is a microprocessor‑based generator protection relay designed for synchronous generators in utility, industrial, and marine applications. It offers a wide range of protection functions, including differential, overcurrent, voltage‑restrained overcurrent, over/undervoltage, over/underfrequency, reverse power, loss‑of‑excitation, and negative‑sequence overcurrent. The STD1 model includes a standard set of I/O and a DC power supply that accepts 85–280 VDC, making it suitable for battery‑backed systems.

This relay features high‑accuracy metering, fault recording, and programmable logic. It supports multiple communication protocols for integration with SCADA and automation systems.

Key Features

• Protection elements: 87G, 51V, 27, 59, 81, 32, 40, 46, 49, 50, 51

• Wide DC supply: 85–280 VDC (also AC option)

• High accuracy: ±0.25% for current and voltage

• Fault recorder with 64 cycles oscillography

• Sequential events recorder (SER) with 1024 events

• Communication: Modbus RTU, DNP3, IEC 61850 (optional)

• Large graphical display with keypad

Technical Specifications

CT inputs: 1A/5A; PT inputs: 100–480 VAC; frequency: 50/60 Hz; power supply: 85–280 VDC or 120/240 VAC; output relays: 12 programmable; operating temperature: -20°C to +70°C; enclosure: IP40.

Applications

Ideal for prime power generators, standby sets, and co‑generation plants. The relay provides primary and backup protection for critical generators.

Installation and Configuration

Install in a standard panel. Connect CTs, PTs, and DC supply. Configure settings via the front panel or BESTCOMS software. The relay includes auto‑configuration wizards.

Reliability and Maintenance

Self‑diagnostics and redundant power supply options ensure high availability. Periodic testing with secondary injection is recommended.

Why Choose the M3425A‑STD1?

This relay offers a comprehensive protection solution with flexible power supply options, making it suitable for a wide range of installations. Beckwith Electric’s reliability and support are unmatched.

In summary, the Beckwith Electric M3425A‑STD1 delivers robust generator protection with advanced features for demanding applications.