The Areva MVAJ104RA0802A is a high-speed, multi-contact auxiliary tripping relay designed to provide reliable circuit breaker tripping and signal isolation within complex protective schemes.
Product Parameters (Datasheet)
- Model Number: MVAJ104RA0802A
- Relay Family: MVAJ (High-speed tripping and control)
- Trip Type: High-speed tripping relay (Fast acting)
- Rated Voltage (Vn): 110V DC (Standard control voltage)
- Number of Contacts: 10 Contacts (Configurable as NO/NC)
- Reset Type: Hand Reset (Indicated by the “R” in the suffix)
- Operating Time: Less than 8ms at rated voltage
- Burden: Low burden during operation to minimize impact on CT/VT circuits
- Enclosure: Size 4 Case (Standard Areva/GEC vertical modular casing)
- Dielectric Withstand: 2kV rms for 1 minute
Country of Origin
This protective component is manufactured by Areva T&D (now part of GE Grid Solutions), with its engineering and manufacturing roots in the United Kingdom (Stafford).
Application Fields
The MVAJ series is essential for high-security electrical protection in:
- Substation Automation: Acting as a “Master Trip” relay to simultaneously trigger multiple circuit breakers.
- Generator Protection: Providing rapid isolation of large turbines during fault conditions.
- Industrial Power Plants: Interfacing between primary protective relays and heavy-duty switchgear.
- Transmission Grids: Signal multiplication where one trip signal must be sent to various monitoring and control points.
Product Usage Instructions
- Mounting: Install the relay in a standard modular rack. Ensure the rear terminal connections are tightened to the specified torque.
- Wiring: Connect the 110V DC trigger source to the coil terminals. Route the output contacts to the breaker trip coils and alarm annunciators.
- Commissioning: Use a relay test set to verify the operating time is within the <8ms specification.
- Resetting: After a trip event occurs, the mechanical flag will drop. Manually reset the relay using the front push-button once the fault has been cleared.
- Maintenance: Periodically check the contact continuity and ensure the mechanical reset mechanism operates smoothly without sticking.
Product Technical Description
The MVAJ104RA0802A is an attracted-armature relay designed for applications where high speed and high contact capacity are paramount. Technically, the “104” designation refers to the specific internal configuration and number of contacts, while the “RA” indicates a hand-reset feature with an operation indicator (flag). This relay is engineered to handle high-inductive loads typical of circuit breaker trip coils. Its design ensures that once the relay is energized, it latches mechanically until a human operator intervenes, ensuring that the “trip” state is clearly documented on the panel.
Q&A (Common Questions)
Q: What is the difference between Hand Reset and Electrical Reset? A: This model (RA) is Hand Reset, meaning an operator must physically press a button on the relay to clear the trip flag. Electrical Reset models can be cleared remotely via a control signal.
Q: Can this relay operate on AC voltage? A: No, the 0802A variant is specifically wound for 110V DC. Using AC will cause the relay to chatter or fail to latch properly.
Q: Why is the operating time (8ms) so important? A: In high-voltage faults, every millisecond counts to prevent catastrophic equipment damage. The MVAJ ensures the circuit breaker begins opening almost instantly after the protective relay detects a fault.
Q: Is this relay compatible with older GEC MVAJ units? A: Yes, Areva MVAJ relays are the direct technical successors to GEC Alsthom and English Electric MVAJ models, often sharing the same footprint and terminal mapping.
Similar Model Recommendations
- Areva MVAJ101 (Simplified 4-contact version)
- Areva MVAJ105 (Electrical reset variant)
- Areva MVAJ204 (Dual-coil configuration)
- Areva MVAA (Standard auxiliary relay, non-tripping)
- Areva MVAX (Trip circuit supervision relay)
For more information on the Areva MVAJ104RA0802A and our full range of protective relay solutions, please visit our website.
