Beckwith Electric's Transformer Protection System M-3311A provides protection, control, monitoring and user interface functions for two, three or four-winding transformers. The system includes restrained and unrestrained differential protection, overcurrent protection, and optional voltage, and underfrequency protection. Multiple setpoint groups and user-implementable logic schemes provide flexibility. Dual RS-232 ports and an RS-485 port provide user-interface capabilities.
Optional modules include the HMI module for front-panel operation and the target module to indicate trip target status and redundant power supply. The M-3311A can be purchased as a differential and overcurrent relay or with the Optional Voltage Protection Package. The M-3826 IPScom Communications Software is included for direct serial or remote communication access. Waveform data can be downloaded using IPScom® while the M-3801D IPSplot PLUS Oscillographic Analysis Software allows for plotting and printing of the downloaded oscillographic data.
- 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, and individual Breaker Failure - Protection for each winding input
- Options: Ethernet Connection and Expanded I/O
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)
- IPSlogicTM
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
- Eight programmable outputs and six programmable inputs
- Oscillographic recording
- Through-Fault Monitoring
- 10-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-3826 IPScom® Communications Software
- IRIG-B time synchronization
- Breaker Monitoring
- Multiple Setpoint Groups
- Trip Circuit Monitoring
- Includes MODBUS and DNP 3.0 protocols
- Summing Currents from mulitple 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
- Expanded I/O (8 additional outputs and 12 additional inputs)