Overview
The GE Multilin 750-P5-G5-S5-HI-A1-R-E, also cataloged as the 750 Feeder Management Relay, operates as a dedicated hardware component for feeder protection, metering, breaker supervision, and control signal processing within electrical distribution protection networks. The unit integrates current measurement inputs, event recording functions, communication interfaces, and feeder automation logic in a panel-mounted drawout platform.
Suffix Breakdown & Model Matrix
| Code | Specification |
|---|---|
| 750 | Feeder Management Relay Series |
| P5 | 5 A phase current transformer inputs |
| G5 | 5 A zero-sequence current input |
| S5 | 1 A sensitive ground current input |
| HI | 88-300 VDC or 70-265 VAC control power supply |
| A1 | Eight 4-20 mA analog outputs |
| R | Red breaker closed LED indication |
| E | Enhanced display and communication package |
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 750-P5-G5-S5-HI-A1-R-E |
| Brand | GE Multilin |
| Product Type | Feeder Management / Protection Relay |
| Series | GE Multilin 750/760 |
| Phase Current Inputs | 5 A CT |
| Zero-Sequence Current Input | 5 A |
| Sensitive Ground Input | 1 A CT |
| Control Power Supply | 88-300 VDC or 70-265 VAC, 48-62 Hz |
| Analog Outputs | 8 x 4-20 mA |
| Display | Enhanced LCD with keypad |
| Communications | Ethernet 10 Mbps, RS232, RS485, RS422 |
| Protocols | Modbus RTU, Modbus TCP/IP, DNP 3.0 Level 2 |
| Setpoint Groups | 4 |
| Oscillography | Up to 10 records, 32 cycles each |
| Operating Temp | Approximately -40 degC to +60 degC |
| Storage Temp | -40 degC to +80 degC |
| Environmental Rating | HI harsh chemical environment option |
| Mounting | Panel-mounted drawout case |
| Weight | Approximately 4.8-6.5 kg |
| Dimensions | Not specified in supplied data |
| Power Consumption | Not specified in supplied data |
| Protection Functions | 50/51, 50G/51G, 67, 67N, REF, 32, 50BF, 25, 79 |
Deterministic Communication and Firmware Integration
The relay supports Ethernet, RS232, RS485, and RS422 communication channels for integration into protection and automation architectures. Supported protocols include Modbus RTU, Modbus TCP/IP, and DNP 3.0 Level 2. Configuration data, event records, metering values, and protection status indications can be exchanged through supervisory systems connected to deterministic industrial communication networks.
The enhanced communication package incorporates local display interaction and remote engineering access functions. Firmware compatibility should be verified against the installed system revision before configuration transfer or relay replacement procedures are performed.
Frequently Asked Questions
Q: Does the relay support multiple protection setting groups?
A: Yes. The unit supports four independent setpoint groups that can be selected according to operating conditions or feeder configurations.
Q: Can oscillography records be captured internally without external recording equipment?
A: Yes. The relay provides internal oscillography storage with up to 10 records and a maximum record length of 32 cycles per event.
Q: What communication interfaces are physically available on the relay?
A: Ethernet 10 Mbps, RS232, RS485, and RS422 interfaces are supported according to the installed communication package.
Field Installation Guidelines
- Verify CT polarity and ratio settings before energizing protection functions.
- Maintain separation between CT circuits, control wiring, and communication cables to reduce induced noise coupling.
- Connect cable shields according to site grounding standards and avoid multiple shield ground points unless required by the plant grounding design.
- Confirm control power voltage falls within the HI input range prior to commissioning.
- Validate protection settings, communication parameters, and I/O assignments before placing the feeder into service.
- Following installation or replacement, perform secondary injection testing and communication verification to confirm correct protection and monitoring operation.
- Review firmware revision compatibility when restoring archived settings from another relay.
