Product Overview

• Part No: MVAJ21L1GB0771B
• Brand: ALSTOM

• Category: Mechanical Latching Trip RelayMVAJ21L1GB0771B belongs to ALSTOM classic MVAJ series high-speed latching auxiliary relay. After receiving protection trip command, the relay operates and maintains contact status via mechanical latch, preventing accidental reset caused by transient signal loss. It provides multiple heavy-duty changeover contacts for circuit breaker tripping, fault alarm and interlock loops. With transparent protective cover and standard draw-out housing, it is widely used as replacement spare for secondary protection cubicles in power plants and high voltage substations.

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Core Features

• Fast operating speed to ensure reliable breaker tripping action
• Mechanical latching function, available for manual or electrical reset
• Multi-pole changeover contacts for multi-circuit signal distribution
• High burden design, resistant to mal-operation induced by cable capacitance
• Transparent front cover for direct status observation and inspection
• Standard plug-in modular construction for rapid on-site replacement
• Built-in surge suppression, excellent immunity to substation electromagnetic interference

• Compliant with EMC, vibration and thermal cycling reliability standards

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Technical Specifications

• Auxiliary Supply: 110V/220V DC
• 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 legacy secondary protection cabinet systems
• Widely applied in thermal power plants, captive power stations and distribution substations
• Used for trip signal amplification, breaker control circuit driving, fault alarming and equipment interlock protection