Description
GE 7750
Technical Specifications
| Parameter | Value |
|---|---|
| Product Family | Multilin 750/760 Series |
| Relay Type | Feeder Management Relay |
| System Configuration | 3-phase, 3 or 4 wire |
| Maximum System Voltage | 600 kV |
| Maximum Current | 5000 A |
| Frequency Range | 25 to 60 Hz nominal (16 to 65 Hz with tracking) |
| Control Power (Low) | 20-60 VDC, 20-48 VAC at 48-62 Hz |
| Control Power (High) | 88-300 VDC, 70-265 VAC at 48-62 Hz |
| Power Consumption | 25 VA nominal, 35 VA maximum |
| Voltage Ride-Through | 16.7 ms at 10% control power |
| Phase CT Primary | 1 to 50000 A |
| Phase CT Secondary | 1 A or 5 A |
| Current Accuracy | ±0.5% of 2×CT (at <2×CT); ±1% of 20×CT (at ≥2×CT) |
| Overload Withstand | 1 second at 80× rated current; continuous at 3× rated current |
| Analog Outputs | 8 channels (0-1 mA, 0-5 mA, 0-10 mA, or 4-20 mA) |
| Output Accuracy | ±1% of full scale |
| Response Time | <6 power system cycles (100 ms at 60 Hz) |
| Output Relays | 8 (2 Form A trip/close, 5 Form C auxiliary, 1 self-test warning) |
| Contact Durability | 100,000 operations at rated load |
| Logic Inputs | 20 (14 rear terminal contact inputs + 20 virtual inputs) |
| Communication Ports | RS232 (front panel), RS485/422 (rear), Ethernet 10Base-T (optional) |
| Protocols | Modbus RTU, Modbus TCP/IP, DNP 3.0 |
| Baud Rate | 300 to 19200 baud |
| Ethernet | 10 Mbps, RJ-45, maximum 4 sessions |
| Clock Resolution | 1 ms |
| IRIG-B Accuracy | ±1 ms |
| Supercap Backup | 45 days |
| Operating Temperature | -40°C to +60°C |
| Storage Temperature | -40°C to +80°C |
| Humidity | Up to 90% non-condensing |
| Pollution Degree | 2 |
Key Features
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Comprehensive Protection: Directional time and instantaneous overcurrent, ground overcurrent, sensitive ground fault, negative sequence, voltage restrained overcurrent, reverse power, under/overvoltage, under/overfrequency
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Automatic Reclosing: Up to 4 shots before lockout (760 series only)
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Synchronism Check: Voltage, frequency, and dead-source checking
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Bus Transfer Scheme: Automatic and manual throw-over capabilities
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Advanced Metering: Full metering including demand and energy calculations
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Event Recording: 512 events with 1 ms timestamp, waveform capture, and fault location
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Data Logger: Continuous monitoring and trending
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Draw-Out Construction: Facilitates quick replacement and testing
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Flash Memory: Field-upgradeable firmware
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Simulation Mode: Built-in testing capabilities
Applications
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Primary protection for distribution feeders
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Backup protection for buses, transformers, and transmission lines
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Overhead line protection with reclosing
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Bus transfer and load shedding schemes
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Distributed generation protection
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Arc flash mitigation
