Description
Key Technical Specifications
| Parameter | Value |
| Device Type | Microprocessor-Based Digital Feeder Protection Relay |
| System Compatibility | Medium- and low-voltage electrical distribution switchgear feeders |
| Protection Functions | Definite and inverse time overcurrent, instantaneous overcurrent, earth fault |
| Current Inputs | Standard 1 A / 5 A secondary CT inputs |
| Auxiliary Power Supply | Wide-range industrial DC/AC control power |
| Communication Interface | Front optical / rear serial communications port supporting standard protocols |
| Output Relays | Programmable trip and auxiliary Form C contact outputs |
| Mounting | Flush panel cutout or semi-flush drawout case design |
| Metering & Recording | True RMS current measurements, event logs, and fault waveform capture |
Product Introduction
Reliable Feeder Protection for Distribution Networks
The GE Multilin MIFIIPI55E00HI00 operates as an advanced digital feeder management relay designed to protect electrical distribution circuits against short circuits, phase overcurrents, and earth faults. Part of the proven MIF II protection family, it combines precise measurement algorithms with configurable protection curves to isolate faulted sections rapidly while maintaining maximum uptime for healthy plant segments.
Engineered for compact switchgear cubicles, this unit offers robust local metering and event recording capabilities. Replacing an older or faulted electromechanical relay with this digital solution improves coordination margins and provides operators with clear fault diagnostics directly from the front display.
MIFIIPI55E00HI00
Application Scenarios & Field Pitfalls (The Engineer’s Perspective)
An uncoordinated or sluggish overcurrent trip on a primary plant feeder breaker can cause a massive upstream bus blackout, dropping multiple process units simultaneously and halting facility production for hours. Substation engineers rely on programmable digital feeder relays to establish precise time-current coordination curves that isolate localized faults instantly.
- Power Generation: Utility and auxiliary plant power distribution switchgear and transformer incoming feeders.
- Oil & Gas: Upstream and downstream facility medium-voltage motor feeder and distribution transformer protection.
- Utilities & Municipalities: Electrical substation feeder management and municipal ring-main distribution units.
- CT Secondary Rating Verification: Ensure the physical CT secondary taps (1 A vs 5 A) match the relay’s internal hardware configuration and software settings. Mismatched CT ratios distort the thermal and overcurrent pickup calculations entirely.
- Auxiliary Control Power Dips: Verify that the incoming control power supply voltage remains stable within rated tolerances. Severe voltage sags on shared DC substation batteries during breaker closing operations can cause processor reboot loops.
- Communication Baud Rate and Protocol Settings: When integrating the relay into a SCADA or substation automation network via the rear serial port, confirm that parity, stop bits, and baud rates align with the master telemetry gateway parameters.
Related Products
- GE Multilin MIFII Series Base Models: Alternative MIF II configurations featuring varied digital I/O counts or specialized high-impedance fault (HIF) detection modules.
- GE Multilin F650: Comprehensive digital feeder protection and bay controller system designed for larger substation architectures.
- Alstom / GE MiCOM P120 Series: Numerical feeder management relays sharing similar application spaces in distribution switchgear.
- GE Multilin EnerVista Setup Software: The standard configuration suite utilized for programming and retrieving event logs from MIF II relays.
- Phoenix Contact MCR Signal Isolators: Industrial signal conditioners used for galvanic isolation on auxiliary analog/binary links.
- Test Switch Blocks (e.g., ABB FT-1 style): Drawout test switches frequently mounted directly beneath feeder relays to allow safe secondary injection testing.
- Belden 9841 RS-485 Cable: Low-capacitance shielded twisted-pair cable utilized for reliable serial communication wiring.
- GE Multilin D20/D30 RTU: Substation data concentrators and remote terminal units aggregating feeder relay data for SCADA master stations.
