Product Short Description
Product Overview
Plug-in high-speed attracted armature auxiliary trip relay originally manufactured by Alstom Grid (now GE Vernova Grid Solutions), designed for high-voltage power substation circuit breaker trip circuit supervision, protection scheme interlocking and fault trip flag indication. Model MVAJ101RB0800A denotes 10 contact configuration, self-reset mechanical operation, standard industrial coil voltage rating and full silver alloy contact sets for heavy DC switching duty in substation DC control circuits.
Description
Technical Core Specifications
- Operating Principle: Attracted armature electromagnetic relay
- Contact Configuration: 10 independent changeover (SPDT) contact sets per unit
- Reset Mechanism: Self-reset automatic mechanical reset after trip operation
- Coil Operating Voltage: Standard industrial substation DC control voltage (suffix 0800A defines coil rating)
- Trip Operating Speed: <10ms fast operate response for high-speed grid fault protection coordination
- Mechanical Endurance Lifespan: Minimum 5 million full operation cycles without contact degradation
- Electrical Contact Rating: Heavy-duty silver alloy contacts rated for substation DC trip circuit current loads
- Mounting Form Factor: Standard Eurocard plug-in relay chassis compatible with Alstom/GE substation protection rack backplanes
- Operating Ambient Temperature: -25°C ~ +70°C
- Environmental Protection: IP5X dust-proof enclosure for indoor substation control panel installation
- Vibration Compliance: IEC 60255-21 substation relay anti-vibration standard
Functional Features
- Ultra-fast <10ms operate time ensures synchronized high-speed circuit breaker tripping during short-circuit grid fault events
- Ten independent SPDT contact sets enable simultaneous multi-circuit interlocking, alarm signaling and protection logic coordination
- Self-reset mechanical design automatically restores contact state after trip coil de-energization without manual intervention
- Embedded mechanical trip flag indicator retains visual fault trip status until circuit reset for post-fault event diagnostics
- High-burden coil design provides immunity to capacitive discharge currents common in long substation trip wiring cables
- Thermal cut-off protection for relay coil prevents winding burnout during sustained energization fault conditions
- Plug-in hot-swappable module design allows relay replacement without full substation panel power shutdown
- Silver alloy contact material resists electrical arcing erosion under repeated DC trip circuit switching cycles
Material & Structural Composition
- Outer Chassis: Heavy-duty die-cast aluminum alloy plug-in frame with anti-corrosion powder coating
- Electromagnetic Core: High-permeability grain-oriented silicon steel armature and yoke assembly
- Operating Coil: Class H high-temperature resistant copper magnet wire wound on insulated plastic bobbin
- Contact Assemblies: Solid silver-cadmium alloy contact tips mounted on spring copper contact arms
- Trip Flag Mechanism: Stainless steel mechanical latch with colored visual indicator window on front panel
- Terminal Socket: Nickel-plated copper screw terminal plug base with lockable wiring clamps
- Shock Dampening: Rubber elastomer anti-vibration pads bonded to chassis mounting points
Working Principle
When DC control voltage energizes the relay operating coil, the generated magnetic field pulls the movable steel armature against the fixed yoke, mechanically switching all ten SPDT contact sets simultaneously. Contact state changes initiate circuit breaker trip signals, fault alarm outputs and protection scheme interlock logic. The self-reset spring mechanism immediately returns the armature and contacts to normal rest position once coil voltage is removed, while a separate mechanical flag latch remains extended to provide permanent visual trip event indication for maintenance staff. High-burden coil construction suppresses spurious relay operation caused by capacitive discharge noise along long substation control wiring cables. Internal thermal fuse components disconnect coil power automatically during sustained overheating from coil short-circuit faults.
Installation Requirements
- Mount vertically inside sealed substation control panels with minimum IP44 environmental protection rating to block dust and humidity ingress
- Route all DC trip circuit wiring separately from high-voltage AC power cables with minimum 10cm physical separation distance
- Torque terminal block wiring screws to standardized 3.5 Nm tension to eliminate loose contact arcing risks
- Install dedicated surge suppression diodes across relay coil terminals to absorb inductive switching voltage transients
- Maintain minimum 20mm clearance between adjacent MVAJ relay modules for heat dissipation
- Use only stranded 1.5–2.5mm² copper substation control cable for all relay circuit connections
Application Scenarios
HV/MV power grid transmission substation circuit breaker trip control, transformer differential protection interlocking, busbar fault supervision relays, generator protection scheme auxiliary signaling, railway traction power substation fault alarm circuits, industrial power plant switchgear control panels
Operation & Maintenance Notes
- Perform annual contact resistance testing to identify arcing-induced contact degradation
- Clean front-panel trip flag viewing windows quarterly to maintain clear fault indication visibility
- Avoid exposure to corrosive sulfur or salt-laden atmospheric environments without sealed panel enclosures
- Do not operate relay coil continuously energized for extended durations exceeding 30 minutes to prevent thermal winding damage
- Replace relay units immediately if contact sticking or slow operate response is detected during routine substation testing
- Document all trip flag activation events to track grid fault frequency and relay operational cycle count
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