GE MM300 Low-Voltage Digital Motor Protection Relay, Modbus

Core Performance & Industrial Application

The GE Multilin MM300 is a digital motor protection and control device for low-voltage three-phase AC motors, integrating protection, metering, diagnostics and communications. It uses an advanced thermal model and provides thermal overload, locked-rotor/jam, undercurrent/underpower, unbalance, ground-fault, over/undervoltage, phase reversal, RTD and thermistor overtemperature protection. It measures current, voltage, power and energy, with up to 256 event records and waveform capture. RS485 Modbus RTU is standard, with optional DeviceNet, Profibus DP and Modbus TCP/IP for direct DCS/SCADA integration; certified to CE, cULus and ISO 9001.

Technical Specifications

▶ Power supply: 60–300 V AC / 84–250 V DC; optional 24–48 V DC

▶ Power consumption: 16 W typical, 25 W maximum 

▶ Phase current input: 0.2–40 A, direct connection up to 5 A FLA 

▶ Relay outputs: up to 18; standard 2×10 A Form A, operate time ≤10 ms 

▶ Digital inputs: up to 30, up to 300 V AC 

▶ Communication: Modbus RTU (standard); optional DeviceNet / Profibus DP / Modbus TCP 

▶ Operating temperature: -20 °C to +60 °C 

▶ Protection rating: IP20 (base unit), IP54 (control panel) 

▶ Dimensions: base unit 12090113 mm 

▶ Weight: approx. 0.75 kg 

▶ Certification: CE, cULus, ISO 9001

Industry Applications

Used in power, petrochemical & oil & gas, water treatment, metallurgy & mining, building materials, pulp & paper, food & beverage and general machinery, mounted in MCC buckets or standalone panels to protect conveyors, pumps, fans and compressors.

Note: Discontinued by GE Vernova; supplied mainly as spares or replacements, verify suffix code and stock before ordering.