Description
- Model: 750-P1-G1-S1-HI-A20-G
- Brand: GE Multilin (General Electric)
- Series: 750/760 Feeder Management Relay
- Core Function: Provides comprehensive protection, control, and monitoring for distribution feeders, motors, and transformers. It serves as a centralized intelligent electronic device (IED) for medium-voltage switchgear.
- Product Type: Digital Protection Relay
- Supply Status: ⚠️ Obsolete (Legacy Series); refurbished units and limited surplus stock available.
- Warranty: 12 Months (From date of shipment)
- Ship From: Shenzhen, China (Common hub for legacy industrial automation parts)
GE SR 750-P1-G1-S1-HI-A20-G
GE SR 750-P1-G1-S1-HI-A20-G
GE SR 750-P1-G1-S1-HI-A20-G
GE SR 750-P1-G1-S1-HI-A20-G
Technical Specification Breakdown
The GE 750-P1-G1-S1-HI-A20-G is a highly specific configuration. Understanding the suffix string is vital to ensure compatibility with your existing panel cutouts and system wiring.
| Feature Code | Description |
| 750 | Base Model (Feeder Management Relay) |
| P1 | Phase Current Inputs: 1A / 5A (Standard Multi-Range) |
| G1 | Control Power: 20-60V DC / 20-48V AC |
| S1 | Communication: RS485 (Rear) + RS232 (Front) |
| HI | Language: English (International Standard) |
| A20 | Mounting: Drawout Case / Standard Panel |
| G | Conformal Coating: Enhanced protection against humidity/corrosion |
The 750 series is the “workhorse” of medium-voltage distribution. It is used to monitor current, voltage, and frequency, providing protection against overcurrent, overvoltage, under-frequency, and breaker failure. In most cases, these relays are integrated into Drawout Cases (A20 mounting), allowing technicians to pull the relay out for testing or replacement without disconnecting field wiring.
Typical Deployment Scenarios
- Feeder Protection: Monitoring distribution lines for faults and isolating sections when necessary.
- Motor Protection: Acting as a primary safeguard against stalling, thermal overload, and single-phasing.
- Transformer Protection: Providing backup overcurrent and differential-related monitoring for small-to-medium utility transformers.
Troubleshooting Quick Reference
❗ SAFETY FIRST: These relays are often connected to live potential transformers (PTs) and current transformers (CTs). Always short the CT circuits before pulling a drawout relay. Failure to do so will result in high-voltage arcing at the CT terminals and risk of severe injury.
- Relay “Self-Test” Fault: If the status LED is red, the relay has detected an internal hardware failure. Access the “Diagnostics” menu via the front port to identify the specific error code (e.g., RAM failure, Watchdog timeout).
- Communication Link Down: If the RS485 link is dropping, check the termination resistors (should be 120 ohms) at both ends of the bus.
- Display/Power Issues: If the display is blank despite the “Control Power” being on, check the internal fuse located inside the relay (if equipped) or ensure the control power voltage is within the specified 20-60V DC range defined by the “G1” suffix.
Procurement & Migration Advice
- Suffix Verification: Before purchasing, confirm that the model number matches your current unit’s “G1” (Control Power) code exactly. Connecting a 125V DC power source to a G1 (20-60V) unit will destroy the power supply board.
- Settings Backup: Use GE’s EnerVista 750 Setup Software to pull the settings file (
.750or.760extension) from your existing relay before it fails. If you replace the relay, you will need this file to configure the new unit; the relay does not “auto-learn” your site-specific protection curves. - Migration Path: Since the 750 series is obsolete, GE recommends moving to the Multilin 850 series for new applications. Note that the 850 has a different footprint and requires a mounting adapter if replacing a 750 unit.
