M-3311 Transformer Protection System
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- For Transformers of All Sizes:
- 2 or 3 winding Transformers
- Unit Wrapping of Generating Plants
- 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, and individual Breaker Failure Protection for each winding input
Standard Protective Functions
- Negative-sequence inverse time overcurrent (46)
- Winding thermal protection (49)
- Three winding instantaneous phase overcurrent (50)
- Breaker Failure (50BF)
- Instantaneous ground overcurrent (50G)
- Instantaneous residual overcurrent (50N)
- Three winding inverse time phase overcurrent (51)
- Inverse time ground overcurrent (51G)
- Inverse time residual overcurrent (51N)
- Three winding, phase differential (87T) and High Set instantaneous (87H)
- Ground differential (87GD)
- Six External input functions with individual timers
Optional Single‑Phase Voltage Protection Package
- Overexcitation (24) V/Hz, two definite time and one inverse time elements
- Phase undervoltage (27) function for load shedding
- Ground Overvoltage (59G)
- Over/Underfrequency (81O/U)
Standard Features
- Four Setpoint Groups
- Eight programmable outputs and six programmable inputs
- Oscillographic recording
- 32-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
- M-3820B IPScom® Communications Software
- IRIG-B time synchronization
- Includes MODBUS, BECO 2200 and DNP 3.0 protocols
Optional Features
- Redundant Power Supply
- M-3911 Target Module
- M-3931 Human-Machine Interface (HMI) Module
- M-3801D IPSplot® PLUS Oscillograph Analysis Software
- For Transformers of All Sizes:
