The Areva MVAJ105RA0802A is a high-speed, multi-contact auxiliary tripping relay designed to provide reliable circuit breaker isolation and signal multiplication within power system protection schemes.
Product Parameters (Datasheet)
- Model Series: MVAJ
- Specific Model: MVAJ105RA0802A
- Relay Type: High-speed tripping and auxiliary relay
- Rated Voltage (Vx): 110-125V DC (Standard for substation control)
- Contact Configuration: 10 Normally Open (N/O) contacts
- Reset Type: Hand Reset (Indicated by the “R” in the model code)
- Operating Time: Less than 10ms (High-speed performance)
- Burden: Low burden to ensure minimal load on the battery system
- Enclosure Size: Size 2 case (Modular draw-out design)
- Mounting: Flush mounting in standard protection racks
- Safety Standard: IEC 60255 compliant for protective relays
Country of Origin
This protective relay was engineered and manufactured by Areva T&D (now part of the GE Grid Solutions / Alstom legacy) in France or the United Kingdom.
Application Fields
The MVAJ105 series is a critical component in high-voltage infrastructure, including:
- Transmission Substations: Acting as the primary trip interface between protection logic and circuit breaker coils.
- Power Plants: Multi-contact signal multiplication for simultaneous tripping of turbines and generators.
- Heavy Industry: Protection of large motors and transformers in steel mills or refineries.
- Railway Power: Managing DC and AC traction power distribution safety.
Product Usage Instructions
- Mounting: Slide the relay module into its compatible case until the internal connectors engage. Ensure the locking handles are secured.
- Wiring: Connect the trip initiation circuit to the coil terminals and the breaker trip coils to the output contacts. Use high-quality crimp terminals for secure connections.
- Resetting: After a trip event occurs, the mechanical flag will drop. You must manually press the reset button on the front panel to clear the target and reset the contacts.
- Testing: Use a secondary injection test set to verify the operating time and contact continuity. Ensure the operating voltage is within the 110-125V DC range.
- Maintenance: Regularly inspect for dust accumulation on the front cover and ensure the mechanical reset mechanism operates smoothly without sticking.
Product Technical Description
The MVAJ105RA0802A belongs to the “M-Series” of instantaneous tripping relays. Technically, it is designed with a high-force magnetic circuit that allows for extremely fast contact closure (sub-10ms), which is vital for minimizing damage during short-circuit faults. The “Hand Reset” feature ensures that the “Trip” command remains latched until an operator acknowledges the fault, providing a physical record of the event via the visual flag. Its robust construction is specifically hardened against high levels of vibration and electrical noise common in HV substation environments.
Q&A (Common Questions)
Q: Can this relay be used for AC tripping circuits? A: This specific model is rated for 110-125V DC. Using it on AC may result in chattering or failure to operate correctly.
Q: What is the difference between MVAJ101 and MVAJ105? A: The MVAJ105 typically features a larger number of output contacts (10 contacts) compared to the standard MVAJ101 model, allowing for more extensive signal multiplication.
Q: Why won’t my relay reset after a trip? A: Ensure the initiating trip signal has been cleared. If the coil is still energized, the mechanical latch will prevent the hand-reset from engaging.
Q: Is the case included with the relay? A: Most MVAJ units are sold as the internal plug-in module. If you require the external housing (case), it must often be specified separately.
Similar Model Recommendations
- Areva MVAJ101 (Standard 4-contact version)
- Areva MVAJ205 (Dual-element tripping relay)
- Alstom MVAX (Auxiliary flag indicator relay)
- GE Multilin MVAJ (Modern GE-branded equivalent)
- Areva MVAA (General purpose auxiliary relay)
For more information on the Areva MVAJ105RA0802A and other protective relaying solutions, please visit our online inventory.
