Feeder & Motor Protection Solution – ALSTOM MVAJ105RA0802A | MVAJ Series
The ALSTOM MVAJ105RA0802A is a numerical protection relay engineered for demanding industrial power distribution environments. Designed within ALSTOM’s proven MVAJ Series, this relay delivers multi-function overcurrent and earth-fault protection for feeders, motors, transformers, and bus sections — making it a cornerstone component in modern MV switchgear panels and substation automation systems.
Where This Product Is Used
The MVAJ105RA0802A is specified by protection engineers and system integrators across the following applications:
- MV Feeder Protection — Overcurrent (ANSI 50/51) and earth-fault (ANSI 50N/51N) protection for medium-voltage distribution feeders in utilities and industrial plants.
- Motor Protection Panels — Thermal overload (ANSI 49), locked rotor, and phase-unbalance detection for large induction motors in pumping stations, compressor drives, and HVAC systems.
- Transformer Incomer Protection — Applied on the LV/MV incomer side of distribution transformers to provide backup overcurrent and restricted earth-fault protection.
- Bus Coupler & Bus Section Schemes — Integrated into busbar protection and interlocking schemes within ring-main units and open-bus substations.
- Oil & Gas / Petrochemical Plants — Deployed in hazardous-area switchrooms where relay reliability and IEC compliance are mandatory.
- Water Treatment & Utilities — Used in pump motor control centers (MCCs) requiring precise thermal modeling and trip-time coordination.
Technical Specifications
- Model: MVAJ105RA0802A
- Manufacturer: ALSTOM (now GE Grid Solutions)
- Series: MVAJ
- Type: Numerical Overcurrent & Earth-Fault Protection Relay
- Protection Functions: ANSI 50, 51, 50N, 51N, 49, 46, 74
- Rated Current Input: 1 A / 5 A (selectable)
- Rated Voltage: 110 V / 220 V AC auxiliary supply
- Frequency: 50 / 60 Hz
- Communication: RS485 / IEC 60870-5-103 (Modbus optional)
- Mounting: Flush panel / 19-inch rack
- Weight: 1.72 kg
- Standards: IEC 60255, EN 50263
Why Engineers Specify This Model
- Multi-function in a single chassis — Combines overcurrent, earth-fault, thermal, and negative-sequence protection, reducing panel footprint and wiring complexity.
- Proven MVAJ platform — Thousands of units deployed globally in utility and industrial substations since the 1990s; extensive field history and spare-parts ecosystem.
- Accurate thermal modeling — ANSI 49 thermal replica with cooling time constant ensures motors are protected against repeated starts and overload cycles.
- IEC 60870-5-103 native support — Plug-and-play integration with SCADA and DCS systems without additional protocol converters.
- Robust construction — Designed for harsh industrial environments; wide operating temperature range and high EMC immunity per IEC 60255-26.
Complete System Bill of Materials
For a complete feeder or motor protection panel using the MVAJ105RA0802A, engineers typically specify:
- ALSTOM MVAJ105RA0802A — Primary protection relay (this unit)
- Current transformers (CTs) — 1 A or 5 A secondary, class 5P20 or 10P10
- Auxiliary power supply module — 110 V or 220 V AC/DC
- RS485 communication cable — Shielded twisted pair, max 1200 m
- Test plug / test block — For in-service secondary injection testing
- Panel-mount enclosure — IP54 or higher for industrial environments
- Trip output relay — If additional output contacts are required
Compliance & Industry Standards
- IEC 60255 — Measuring relays and protection equipment
- IEC 60870-5-103 — Companion standard for protection equipment communication
- EN 50263 — Measuring relays and protection equipment (European)
- ANSI/IEEE C37.90 — Relays and relay systems associated with electric power apparatus
- CE Marked — Compliant with EU Low Voltage and EMC Directives
Quality Assurance & Sourcing
All ALSTOM MVAJ105RA0802A units supplied by Konmask.com are:
- Sourced from authorized distributors or verified surplus channels with full traceability
- Inspected for physical integrity, label authenticity, and firmware version prior to dispatch
- Shipped with original documentation where available (test certificates, manuals)
- Backed by our 30-day return policy and post-sale technical support
- Packaged in anti-static, shock-resistant materials for safe international transit
How to Source This Part
To place an order or request a quotation for the ALSTOM MVAJ105RA0802A:
- Online: Add to cart directly on this page — stock is updated in real time.
- Email RFQ: Send your BOM or purchase order to [email protected]
- Phone / WhatsApp: +0086 19859288691 (Mon–Fri, 09:00–18:00 CST)
- Lead time: In-stock units ship within 1–3 business days; ex-stock orders confirmed within 24 hours.
Application-Specific FAQ
Q: Is the MVAJ105RA0802A suitable for both feeder and motor protection?
A: Yes. The MVAJ105 variant includes thermal overload (ANSI 49) and negative-sequence (ANSI 46) functions, making it suitable for both feeder overcurrent and motor protection applications.
Q: What communication protocol does this relay support?
A: The standard firmware supports IEC 60870-5-103 over RS485. Modbus RTU is available on select firmware versions — please confirm with our team at order time.
Q: Can this relay be tested in-service without de-energizing the panel?
A: Yes, when used with a compatible test plug/test block, secondary injection testing can be performed without interrupting the primary circuit.
Q: What is the auxiliary supply voltage for this model?
A: The RA0802A suffix denotes 110 V AC/DC auxiliary supply. Please verify your panel supply voltage before ordering.
Q: Do you supply the relay with a settings file or configuration?
A: We supply the hardware unit. Settings configuration is application-specific and should be performed by a qualified protection engineer using ALSTOM’s MiCOM S1 Studio or equivalent tool.
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