The MIB30LOCE00000 is a specialized High Impedance Differential Protection Relay from the GE Multilin MIB series. It is engineered to provide high-speed, selective protection for busbars, transformers, and large motors by monitoring the differential current between CTs. The “High Impedance” principle ensures the relay remains stable during heavy external through-faults—even with CT saturation—while providing instantaneous tripping for internal faults. This digital unit replaces traditional electromechanical high-impedance schemes with enhanced diagnostics and communication capabilities.
Product Parameters
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Model: MIB30LOCE00000
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Protection Type: High Impedance Differential (87)
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Current Input: 1A or 5A (Universal CT secondary compatibility)
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Input Voltage: 110V – 250V DC / 110V – 230V AC (Standard Control Power)
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Pickup Range: Adjustable current setting for sensitive fault detection
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Burden: Low internal burden to minimize CT requirements
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Output Contacts: High-speed tripping and alarm relays
Product Specifications
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Interface: Front-panel LCD with tactile navigation keys
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Communications: RS485 Modbus RTU support for SCADA integration
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Mounting: Panel mount / Draw-out case architecture
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Sampling Rate: High-frequency digital sampling for precise waveform analysis
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Event Recording: Internal memory for sequence-of-events (SOE) and fault logging
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Enclosure: Robust metallic housing for EMI/RFI shielding
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Filtering: Digital filtering to reject DC offset and harmonics
Application Fields
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Busbar Protection: Rapidly isolating faulted bus sections in substations.
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Transformer Protection: Sensitive restricted earth fault (REF) protection.
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Large Motor/Generator Protection: Detecting internal phase-to-phase or phase-to-ground faults.
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Industrial Power Plants: Protecting critical distribution nodes and switchgear.
Q&A
Q: Why is “High Impedance” used instead of standard differential protection? A: It provides superior stability against “spurious” differential currents caused by CT saturation during external faults, ensuring the system only trips for faults inside the protected zone.
Q: Does the MIB30LOCE00000 require external stabilizing resistors? A: Yes, like most high-impedance schemes, it typically requires an external stabilizing resistor and a non-linear resistor (Metrosil) to limit peak voltages during faults.
Q: Can I monitor the relay status remotely? A: Yes, the “E” in the configuration often designates enhanced communication options, allowing remote monitoring via Modbus protocols.
Q: Is this relay suitable for both 50Hz and 60Hz systems? A: Yes, the digital processor is designed to operate across standard industrial power frequencies.
