M-3311A Transformer Protection (2, 3, or 4-Winding) Relay

Protect Transformers and Other Important Power System Apparatus.

  • For Transformers of All Sizes:
    • 2, 3 or 4 winding Transformers for Transmission and Distribution applications
    • Generator-Transformer Unit Overall Differential
    • Unit Protection of Other Electrical Apparatus and certain Bus Arrangements (including those with a transformer in the zone)
  • Additional Applications:
    • System Backup Protection
    • Load Shedding (voltage and frequency)
    • Bus Protection
    • Individual Breaker Failure Protection for each winding input
  • Available voltage configurations include zero, two or four voltage inputs
  • Ground Differential configurations include one, two or three current inputs
  • Optional Ethernet Connection and Expanded I/O
  • Optional Voltage Package includes:
    • 24 Volts/Hz Overexcitation
    • 27 Phase Undervoltage
    • 59G Ground Overvoltage
    • 81O/U Over/Under Frequency

Standard Protective Functions

  • Negative-sequence inverse time overcurrent (46)
  • Winding thermal protection (49)
  • Four winding instantaneous phase overcurrent (50)
  • Breaker Failure (50BF)
  • Instantaneous ground overcurrent (50G)
  • Instantaneous residual overcurrent (50N)
  • Four winding inverse time phase overcurrent (51)
  • Inverse time ground overcurrent (51G)
  • Inverse time residual overcurrent (51N)
  • Two, three or four winding phase differential (87T) and high set instantaneous (87H)
  • Ground differential (87GD)
  • IPSlogic®

Optional Voltage Protection Package

  • Overexcitation (24) V/Hz, two definite time and one inverse time elements
  • Phase Undervoltage (27) function for load shedding
  • Phase Overvoltage (59)
  • Ground Overvoltage (59G)
  • Over/Underfrequency (81O/U)

Standard Features

  • Eight programmable outputs and six programmable inputs
  • Oscillographic recording
  • Through-Fault Monitoring
  • 8-target storage
  • Real time metering of measured and calculated parameters, including demand currents
  • Two RS-232 and one RS-485 communications ports
  • Standard 19″ rack-mount design
  • Removable printed circuit board and power supply
  • 50 and 60 Hz models available
  • 1 or 5 A rated CT inputs available
  • S-3300 IPScom® Communications Software
  • IRIG-B time synchronization
  • Sequence of Events Log
  • Breaker Monitoring
  • Multiple Setpoint Groups
  • Trip Circuit Monitoring
  • Includes MODBUS and DNP 3.0 protocols
  • Summing Currents from multiple sources for 49, 50, 51, 50N, 51N, 87 GD and Through Fault functions

Optional Features

  • Redundant Power Supply
  • M-3911A Target Module
  • M-3931 Human-Machine Interface (HMI) Module
  • M-3801D IPSplot® Plus Oscillograph Analysis Software
  • RJ45 Ethernet port utilizing MODBUS over TCP/IP, BECO 2200 over TCP/IP, IEC 61850 or DNP 3.0 protocol
  • Expanded I/O (8 additional outputs and 12 additional inputs)
  • Standard and Expanded I/O Models available in vertical panel mount
  • Close Circuit Monitoring on Expanded I/O units

M-0423 Serial Null-Modem Cable

M-3908 Universal Contact Input Adapter

M-3949 Redundant Low Voltage Power Supply