GE 750-P5-G1-S5-HI-A20-R-E-H Multilin 750 Series Relays

The GE Multilin 750-P5-G1-S5-HI-A20-R-E-H, also cataloged as the 750-P5-G1-S5-HI-A20-R-E-H Feeder Management Relay, serves as the primary 750 Feeder Management Relay utilized to execute comprehensive monitoring, circuit breaker control, and automated overcurrent fault isolation within harsh or high-contamination industrial power distribution networks.

Suffix Breakdown & Model Matrix

The SR750 series utilizes explicit alphanumeric codes within its ordering matrix to define the integrated hardware options and functionality block baseline:

• 750: Core basic unit designator for the Feeder Management Relay series.
• P5: 5 A phase current secondary inputs equipped for standard CT interfacing.
• G1: 1 A zero sequence current inputs paired with sensitive ground current detection hardware.
• S5: Enhanced feature set package containing advanced protection control options (such as breaker failure, synchrocheck, or auto-reclose).
• HI: High-voltage universal control power supply block (88-300 VDC / 70-265 VAC).
• A20: Advanced analog I/O configuration containing eight 4 to 20 mA analog outputs.
• R: Enhanced red breaker closed status LED indicators installed on the front faceplate.
• E: Enhanced diagnostics functionality equipped with an enhanced faceplate layout.
• H: Harsh environment conformal coating option applied to internal circuit boards.

Hardware Specifications

Industrial Control & Power System Specifications

• Backplane Bus Communication Velocity and Density Scaling The relay captures detailed network waveforms through a dedicated multi-channel processing architecture. It updates internal telemetry registers with current waveforms, voltage signals, logic input states, and output relay parameters simultaneously, ensuring instantaneous transmission over the serial communication link to upstream PLCs or SCADA platforms without causing data bottlenecks.
• Deterministic Protection Simulation and Trace Memory Execution The hardware features an isolated internal self-assessment and process simulation engine. This system allows technicians to test advanced protection algorithms (such as the directional overcurrent or voltage elements configured within the S5 block) and map virtual faults directly to Trace Memory without applying external primary AC injection sources, ensuring mathematically pure variable generation for verifying custom logic setpoints.

Frequently Asked Questions

Q: What specific protection does the final "H" suffix provide for the internal assemblies?

A: The "H" suffix indicates that the internal printed circuit boards (PCBs) have been treated with a specialized conformal coating. This protective layer shields the sensitive digital electronics from airborne contaminants, moisture, fine dust, and corrosive gases (such as hydrogen sulfide) common in chemical processing, oil, and gas facilities.

Q: What advanced protection elements are typically added by the "S5" functionality block relative to basic standard configurations?

A: The "S5" configuration suffix expands the software module baseline to include specialized feeder automation controls. This includes automated multi-shot circuit breaker reclosing (auto-reclose), synchronism checking (synchrocheck) for network paralleling, breaker failure detection logic, and enhanced voltage/frequency protection loops.

Field Installation Guidelines

• Chassis Alignment, Drawout Seating, and Enclosure Mounting Mount the relay vertically within a standard switchgear panel cutout. Slide the drawout chassis straight into its designated outer enclosure casing until the heavy-duty rear terminal blocks align and lock into place, verifying that the front faceplate seal is firmly compressed against dust ingress.
• Signal Routing, Trace Grounding, and Analog Shield Shielding Route all low-voltage 4 to 20 mA analog output circuits and discrete logic signal lines through separate grounded steel conduits away from high-power current transformer (CT) and voltage transformer (VT) secondary leads. Bond all control cable shields to the local protective earth grounding bar at a single point to eliminate induced electrical noise or signal distortion.