Generator Protection
M-3425A Comprehensive Generator Relay
M-3410A Small Generator Relay

Apply Integrated Generator Protection to Meet or Exceed Standards, While Providing Maintenance & Operational Information

Beckwith Electric protection relays provide you with the ability to meet or exceed ANSI/IEEE C37.102 or Buff Book standards, plus give you additional operational and security enhancements.


Reduce project and ownership costs

  • Standardization for most small, medium, and large generators
  • Commissioning tools to speed testing and field start-up
  • Configurable and selectable elements to meet protection challenges for different sizes, machine types, and groundings of generators

Enhanced security and operational use

  • Dynamic restraint differential element for security on black starts and heavy faults (CT saturation and large DC offset problems)
  • Field ground fault protection includes brush lift-off detection and active field ground resistance measurement for reliability- centered maintenance
  • Large frequency response: 10-70 Hz for key elements
  • Optional use of phase-to-phase voltages when using phase-to-ground PTs for the undervoltage (27), overvoltage (59) and overexcitation (24) elements. This avoids nuisance tripping for stator ground faults, and ground faults on ungrounded buses when backfeeding plant auxiliaries.
  • Underfrequency accumulator for steam and combined cycle turbine applications.

Safeguard the Source!

Beckwith Electric generator protection relays meet the challenges of utility and industrial generator protection. The primary objectives for the relays are to provide economy and integration of functions. They use element designs that enhance security against false tripping- helping maintain your power generation revenue stream and process.

Protection and More

The M-3410A and M-3425A provide protection against short circuits, abnormal operating conditions, abnormal system conditions, prime mover failures and excitation system problems. These Integrated Protection Systems (IPS) expand the efficiency of your operation by providing extended functions such as metering, monitoring, event logging, waveform capture (oscillography), and local/remote serial communications.

Scalable Application

Based on generator-rated power and grounding, the M-3410A and M-3425A allow you to select the optimum balance of protection while keeping cost at a minimum.

Meeting Utility and Industrial Standards

Beckwith Electric generator protection relays meet pertinent ANSI, IEC, UL and CSA standards, including ANSI C37-90.3 RFI at 35 V/M. This is helpful for standardization purposes worldwide. The M-3410A is also CE compliant. Beckwith Electric is an ISO 9001 certified company.

Communications Ability

The M-3410A employs MODBUS RTU, and the M-3425A employs MODBUS RTU, and BECO 2200 protocols. RS-232, RS-485 and optional Ethernet connectivity for integration into power plant control systems or utility SCADA is available.

Testing, Commissioning, and Warranty Investigation Tools

The metering functions include sequence components and power calculations. With these, it is it is quick and easy to verify proper wiring of complete protection systems- from the instrument transformers to the relay, and everything in between. Improper phasing and polarity reversals are easily seen as high negative sequence quantities. IPSplot, our software program for viewing captured waveforms (digital oscillography), is available as a small cost extra for the relay, and is a comprehensive tool for detailed event analysis. The M-3425A employs an IRIG-B input for coordinated time-stamping of events with other devices.


The Integrated Protection Systems communications software (IPScom) provides easy configuration, and setting and viewing of logs and data from the relay. All interactions are divided into small, logical steps. The software can be used to print all configurations and settings to automate the documentation process.

Application Flexibility

Programmable I/O allows the elements to be linked to various output contacts, and to be blocked by control (contact sensing) inputs. This flexibility allows the M-3410A and M-3425A to meet various trip logics as mandated by each application. The suite of elements can be configured to meet different protection requirements for type of generator (induction, synchronous or asynchronous), size, connection type, and grounding.