Product Overview

• Part No: MCTI40N1AB0751G
• Brand: ALSTOM

• Category: Negative Sequence Overcurrent Protection RelayMCTI40N1AB0751G is part of ALSTOM MCTI series static plug-in relay. It measures negative sequence current generated by unbalanced three-phase conditions such as phase loss, phase unbalance and asymmetrical short circuits. Once the measured value exceeds preset threshold and persists for set delay, the relay activates output contacts for alarm or tripping, preventing thermal damage to rotating machines. Featuring adjustable setting knobs and transparent protective cover, it serves as essential spare equipment for generator and motor protection panels.

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Core Features

• Sensitive detection of negative sequence current caused by unbalanced faults
• Adjustable operating threshold and time delay for flexible protection coordination
• Transparent front cover facilitating parameter adjustment and status inspection
• Standard plug-in modular design enabling fast on-site replacement
• Reliable changeover contacts for alarm and trip control circuits
• High electromagnetic interference resistance suitable for power plant environments

• Compliant with EMC, vibration and thermal cycling reliability standards

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Technical Specifications

• Auxiliary Supply: 110V/220V AC/DC
• Rated CT Input: 1A / 5A
• Operating Frequency: 50/60Hz
• Operating Temperature: -20°C ~ +60°C
• Storage Temperature: -40°C ~ +85°C
• Installation: Chassis plug-in mounting

• Front Protection Class: IP40

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Compatibility & Application

• Compatible with ALSTOM conventional secondary protection cabinet systems
• Widely used in thermal power plants, captive power stations and heavy industrial sites
• Applied for negative sequence protection of synchronous generators, large induction motors and turbo machinery