ALSTOM MVAJ23B1AB0757B – Heavy‑Duty Auxiliary/Tripping Relay for Protection Panels

The ALSTOM MVAJ23B1AB0757B belongs to the proven MVAJ series of attracted‑armature auxiliary relays widely used in substation and switchgear protection schemes. From my experience, the MVAJ 20‑series relays are chosen when you need dependable trip duty, clean changeover contacts, and a familiar draw‑out case that maintenance teams already trust. This model is typically used for breaker tripping, interlocking, and signaling where fast operation and strong contact performance are essential.

Company’s Order Placement Process and Guarantees

• Warranty: 365 days
• Lead time: 1 week if in stock; no more than one month at the latest
• Payment: 50% advance payment; full payment before delivery
• Express options: FedEx, UPS, DHL
• Packaging: anti‑static, shock‑absorbing export packing; relay shipped with protective case cover

Key Features

• Heavy‑duty attracted armature – Designed for trip/interlock duty in protection systems with fast pickup and robust mechanics.
• Multiple changeover contacts – Typically provides several volt‑free C/O contacts for parallel signaling and control.
• Draw‑out case – You might notice the Midos‑pattern draw‑out style that simplifies testing and replacement without disturbing panel wiring.
• Coil voltage flexibility – Common coils are 110/125 Vdc or 220/250 Vdc; matching the installed scheme is straightforward.
• Clear indication – Many MVAJ variants include mechanical flags for quick trip status at the panel (hand reset or self reset depending on code).
• IEC protection practice – Built for utility environments, typically aligned with IEC 60255 performance expectations.

Technical Specifications

Note: The exact coil voltage, contact arrangement, and reset/flag options are defined by the full code “MVAJ23B1AB0757B”. If you share a photo of the nameplate, we can confirm specifics before shipping.

Application Fields

• Medium and high‑voltage switchgear protection panels (breaker trip/interlock)
• Substation control and automation cubicles for signaling and scheme logic
• Generator and transformer protection schemes (auxiliary trip, lockout assistance)
• Retrofit of legacy ALSTOM/AREVA/GE protection panels needing form‑fit‑function compatibility

Advantages & Value

• Reliability in trip duty: MVAJ units are known for consistent pick‑up and strong contact pressure, even after years in service.
• Compatibility: Draw‑out case and terminal pattern match existing protection panels in many cases, minimizing wiring changes.
• Procurement efficiency: Faster commissioning compared with re‑engineering logic around a different relay family.
• Support and spares: We help confirm coil voltage, contact mapping, and any suppression accessories to avoid site delays.

One thing I appreciate is how maintenance techs can test these in a cradle without disturbing panel wiring. A utility customer told us they swapped in a like‑for‑like MVAJ in under 15 minutes during a planned outage—no terminal rework, just verify coil voltage and go.

Installation & Maintenance

• Panel/cabinet: Mount in a clean, ventilated protection cabinet; allow front clearance for draw‑out handling.
• Wiring: Use ferruled conductors; confirm coil voltage on the nameplate before energizing; observe polarity for any DC suppression modules.
• Trip circuit health: Keep total loop resistance within scheme limits; apply surge suppression across inductive loads to protect contacts.
• Routine checks: Function test at intervals (often 6–12 months), verify contact resistance, clean dust, and check flag/reset operation.
• Spare strategy: Keep at least one spare relay with the same coil and contact configuration for critical feeders or transformers.

Quality & Certifications

• Designed in line with utility protection practice and IEC 60255 performance concepts
• Typically CE‑marked when supplied for the EU market
• RoHS applicability may vary with production batch; we can confirm upon request
• Supplied with a 365‑day warranty

Helpful Accessories & Related Items

• Midos‑style test block (e.g., ALSTOM/GE MMLG) for safe secondary testing
• Arc‑suppression components (RC snubbers or diodes) for inductive loads across contacts
• Replacement terminal labels, case gaskets, and draw‑out cradle hardware

If you can share the exact scheme requirement (coil voltage, number of C/O contacts, reset/flag preference), we’ll match it against MVAJ23B1AB0757B and ship the correct unit with test data.