Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 750-P5-G5-S5-HI-A20-R-E |
| Manufacturer | GE Multilin (General Electric) |
| Product Type | Feeder Management Relay / Protection Relay |
| Series | GE Multilin 750 / SR750 |
| Phase Current Inputs | 5 A CT secondary (P5) |
| Ground Current Inputs | 5 A CT secondary (G5) |
| Sensitive Ground Input | 5 A CT secondary (S5) |
| Control Power | 88–300 VDC / 70–265 VAC, 48–62 Hz (HI) |
| Analog Outputs | 8 × isolated 4–20 mA configurable channels (A20) |
| Communication Protocols | Modbus RTU, DNP 3.0 |
| Communication Ports | Front RS232; Rear RS485/RS422 |
| Waveform Sampling Rate | 16 samples per cycle |
| Operating Temperature | -20°C to +60°C |
| Dimensions (W × L × H) | 7 in × 6.5 in × 8.5 in (178 × 165 × 216 mm) |
| Weight | Approximately 7.9 kg |
| Mounting | Draw-out case, 19-inch rack or panel cutout |
Main Features and Advantages
Comprehensive feeder protection: The 750-P5-G5-S5-HI-A20-R-E provides phase time and instantaneous overcurrent, neutral overcurrent, ground overcurrent, sensitive ground fault, negative-sequence overcurrent, and breaker failure protection. The sensitive ground element is particularly valuable in resistance-grounded or ungrounded distribution systems where low-magnitude fault currents must be detected reliably.
Dual-microprocessor architecture: A Motorola 68332 32-bit processor handles analog signal acquisition and protection logic, while a separate 16-bit processor manages the display, LEDs, and communication interfaces . This division ensures that protection functions continue uninterrupted even during heavy communication traffic, a critical advantage in SCADA-intensive installations.
Eight isolated analog outputs: The A20 option on the 750-P5-G5-S5-HI-A20-R-E provides eight configurable 4–20 mA channels, allowing direct hardwired transmission of measured values such as phase currents, power, or demand to legacy DCS and SCADA systems that do not support serial protocols . This capability extends the relay’s usefulness in older control architectures where full network integration is impractical.
Draw-out construction: The 750-P5-G5-S5-HI-A20-R-E is housed in a draw-out case that automatically short-circuits CT inputs upon withdrawal, enabling safe field replacement without rewiring panel connections . This design minimizes downtime during maintenance or module replacement.
Application Field
The 750-P5-G5-S5-HI-A20-R-E is deployed primarily in medium-voltage distribution feeders within industrial plants, commercial facilities, and utility substations. Its protection functions address the full range of feeder fault conditions, from high-magnitude phase-to-phase faults to resistive ground faults that produce only a few amperes of current.
In industrial power distribution, the 750-P5-G5-S5-HI-A20-R-E protects incoming feeders, bus ties, and outgoing feeder circuits in manufacturing plants, refineries, and mining operations. The relay’s eight analog outputs enable integration with plant DCS systems for real-time current and power monitoring without requiring protocol conversion gateways.
Utility distribution networks deploy the for overhead and cable feeder protection. Its waveform capture and event recording functions support post-fault analysis, helping utilities identify fault causes and verify protection coordination. The relay’s Modbus and DNP 3.0 communication options facilitate integration with SCADA systems for remote monitoring and control.
Legacy system sustainment represents a significant application for the . As the 750 series remains in active service across many facilities, compatible replacement units are essential when existing relays reach end of life or require firmware updates. The serves as a like-for-like replacement that maintains configuration compatibility and wiring interfaces.
