The Areva MVAJ105RA0802A is a high-speed, multi-contact tripping relay designed for use in protection and control schemes where high reliability and fast operating times are essential for isolating electrical faults.
Product Parameters (Datasheet)
- Model Number: MVAJ105RA0802A
- Type: MVAJ 105 (High Burden / Self-Reset)
- Configuration: 10 Contacts (Configurable NO/NC combinations)
- Rated Voltage (Vx): 110/125 V DC (Standard for 0802A variant)
- Operating Time: Typically less than 10ms (High-speed performance)
- Burden: High burden to ensure immunity against induced interference or capacitive discharge in long wiring runs
- Reset Type: Self-resetting (Contacts return to original state once the initiating signal is removed)
- Mounting: Draw-out case (Size 2 horizontal)
- Contact Rating: 10A Continuous, 30A Making/Breaking (System voltage dependent)
Country of Origin
This protective relay was originally engineered and manufactured by Areva T&D (now part of the GE/Alstom heritage) in the United Kingdom.
Application Fields
The MVAJ series is a critical component in substation automation and industrial power networks:
- Circuit Breaker Tripping: Acting as the intermediary between sensitive protection relays and the heavy-duty breaker trip coils.
- Logic Multiplication: Creating multiple independent signals from a single protection output for interlocking and alarm systems.
- Industrial Plants: Providing robust fault isolation in steel mills, chemical processing, and oil refineries.
- Transmission & Distribution: Used in high-voltage substations to ensure rapid clearance of short circuits.
Product Usage Instructions
- Case Mounting: Ensure the case is securely flush-mounted in the relay panel. The draw-out feature allows the internal relay element to be removed without disturbing the external wiring.
- Wiring: Verify that the auxiliary supply (Vx) matches the nameplate rating (110/125V DC). Use shielded cables if routing through high-noise environments.
- Contact Configuration: Check the internal link settings or terminal wiring to confirm the desired Number of Normally Open (NO) and Normally Closed (NC) contacts.
- Commissioning: Perform a secondary injection test to verify the operating time and contact continuity.
- Safety: Never remove the relay element from the case while the circuit is live without ensuring the CT circuits (if integrated in the scheme) are shorted.
Product Technical Description
The MVAJ105RA0802A is a “Trip Relay-2” specifically designed to prevent “contact bounce” and ensure a decisive, high-speed response. The “High Burden” characteristic is a safety feature; it requires a specific level of energy to operate, which prevents accidental tripping caused by “spill” currents or electromagnetic interference in large substation environments. Its robust mechanical construction allows it to handle the high vibration and thermal stresses often found in power distribution switchgear.
Q&A (Common Questions)
Q: Is the MVAJ105 a hand-reset or self-reset relay? A: The “RA” in this specific code (MVAJ105RA) denotes a self-resetting model. Hand-reset models typically use different suffixes like “RH”.
Q: Can I use this relay for AC voltage applications? A: This specific model is rated for DC auxiliary supplies. Using it with AC may cause buzzing or failure to operate correctly unless specified on the nameplate.
Q: What is the benefit of the “High Burden” feature? A: High burden ensures the relay does not trip falsely due to the discharge of wiring capacitance, which is common in long, complex cable runs between the relay room and the switchyard.
Q: How do I know if the relay has tripped? A: Most MVAJ models feature a mechanical flag (indicator) that drops or changes color when the relay is energized.
Similar Model Recommendations
- Areva MVAJ101 (Fewer contact variant)
- Areva MVAJ105RH (Hand-reset version)
- Areva MVAJ205 (Size 4 case with more contacts)
- GE/Alstom MVAJ105RA0801A (Different voltage variant)
- Areva MVAW (Standard burden version)
For technical datasheets or to order the Areva MVAJ105RA0802A, please visit our product portal for industrial protection solutions.
