The Areva MVAJ104RA0802A (Part of the MVAJ series) is a high-speed, multi-contact auxiliary tripping relay specifically engineered to provide rapid and secure circuit breaker operation in high-voltage protection schemes.
Product Parameters (Datasheet)
- Model Number: MVAJ104RA0802A
- Relay Type: High-Speed Master Tripping Relay
- Rated Voltage (Vn): 110V / 125V DC
- Contact Configuration: 10 Contacts (typically 10 NO or a mix of NO/NC depending on internal wiring)
- Reset Type: Hand Reset (Mechanical Flag Indicator)
- Operating Time: Extremely fast (< 8ms at rated voltage)
- Burden: Low burden on the initiating circuit
- Case Size: Size 4 (Standard vertical modular casing)
- Dielectric Withstand: 2kV rms for 1 minute
- Operating Temperature: -10°C to +55°C
Country of Origin
This protective component is manufactured by Areva T&D (now integrated into GE Grid Solutions) in the United Kingdom, maintaining the legacy and reliability of the original GEC Alsthom protection designs.
Application Fields
The MVAJ104 series is critical for “Master Trip” logic in power systems:
- Substation Protection: Distributing a single fault signal to multiple breakers and SCADA systems simultaneously.
- Generator Sets: Rapidly isolating large-scale synchronous machines during thermal or electrical faults.
- Industrial Switchgear: Acting as the heavy-duty interface between sensitive electronic relays and high-power trip coils.
- Transmission Grids: Providing reliable interlocking and signal multiplication across complex busbar schemes.
Product Usage Instructions
- Mounting: Install the relay into its modular chassis. Ensure the rear terminal blocks are correctly aligned for the drawout mechanism.
- Wiring: Connect the 110/125V DC trip pulse from the primary protection relay to the MVAJ coil terminals. Map the output contacts to the relevant breaker trip coils and annunciators.
- Mechanical Reset: Because this is a Hand Reset (“RA”) model, the relay will remain in the “tripped” state even after the fault is cleared. A technician must manually press the reset button on the front of the relay to return the contacts to their normal state.
- Testing: Perform secondary injection tests to verify the operating time is within the < 8ms threshold. Use the mechanical flag to confirm operation.
- Safety: Never use the relay contacts to directly switch loads exceeding the breaking capacity specified in the technical manual, especially for high-inductance DC circuits.
Product Technical Description
The MVAJ104RA0802A functions as an attracted-armature relay. When the coil is energized by a protection signal, the armature moves at high speed to change the state of all 10 contacts. Technically, the “RA” designation denotes a mechanical latch and hand-reset mechanism with a visible operation flag. The “0802A” suffix specifically identifies the winding and contact materials optimized for 110V/125V DC station batteries. This relay is engineered to withstand the intense electromagnetic environment of a fault event, ensuring that the trip signal is never lost or delayed.
Q&A (Common Questions)
Q: What happens if I don’t reset the relay after a trip? A: The contacts will remain in the “tripped” state, potentially preventing the circuit breaker from being closed again, depending on your system’s interlocking logic.
Q: Can this relay be triggered by an AC signal? A: No, the MVAJ104RA0802A is specifically wound for DC. AC signals will cause incorrect operation or failure to latch.
Q: Is this relay interchangeable with the MVAJ101? A: The MVAJ104 has more contacts (10) compared to the MVAJ101 (usually 4). While the electrical principles are the same, the wiring and case size may differ.
Q: Why does it use a mechanical flag instead of just an LED? A: Mechanical flags are preferred in substation environments because they remain visible even if the auxiliary power to the panel is completely lost during a major fault.
Similar Model Recommendations
- Areva MVAJ101 (Compact 4-contact version)
- Areva MVAJ105 (Electrical reset version)
- Areva MVAJ204 (Dual-coil configuration)
- Areva MVAA (Standard auxiliary relay, non-tripping)
- Areva MVAX (Trip circuit supervision relay)
For procurement and technical support regarding the Areva MVAJ104RA0802A and other protection relay solutions, please contact our technical sales team.
