The GEC Alsthom MVAX12B1CA0753A is a high-reliability auxiliary relay designed for use in protection and control schemes, providing essential contact multiplication and circuit isolation with high-speed performance.
Product Parameters (Datasheet)
- Model Number: MVAX12B1CA0753A
- Relay Type: MVAX 12 (Multi-contact Auxiliary Relay)
- Rated Voltage (Vx): 110/125 V DC
- Contact Configuration: 8 Contacts (Typically configured as 4 NO / 4 NC, or 6 NO / 2 NC depending on specific factory setting)
- Operating Time: Less than 15ms at rated voltage
- Reset Type: Self-resetting (Contacts return to normal state upon removal of the initiating signal)
- Burden: Low burden (ensures minimal power consumption from the auxiliary battery)
- Case Size: Size 2 (Standard draw-out horizontal case)
- Terminals: Screw-type rear terminals for secure connection
Country of Origin
This protective component was engineered and manufactured by GEC Alsthom (now integrated into the GE/Alstom grid heritage) in the United Kingdom.
Application Fields
The MVAX series is utilized as a vital logic element in high-voltage substations and heavy industrial plants:
- Signal Multiplication: Taking a single output from a protection relay and creating multiple independent signals for tripping, alarming, and SCADA logging.
- Control Interlocking: Managing safety interlocks for circuit breakers and disconnect switches.
- Isolation: Providing a robust electrical barrier between sensitive electronic controllers and high-energy primary circuits.
- Remote Signaling: Driving remote indicators and mimic panels in central control rooms.
- Power Generation: Coordinating control sequences in coal, gas, and nuclear power facilities.
Product Usage Instructions
- Mounting: Install the relay case into a standard panel cutout. The draw-out design allows for easy removal of the relay unit for testing without disturbing the wiring.
- Wiring: Ensure the DC supply polarity is correct as per the terminal diagram. Use appropriately rated wire for the contact loads (typically 1.5mm² or 2.5mm²).
- Contact Check: Before commissioning, verify the contact arrangement (Normally Open/Normally Closed) using a continuity tester while the relay is de-energized.
- Voltage Verification: Confirm the auxiliary supply falls within the 110/125V DC operating range to ensure decisive contact closure.
- Maintenance: Periodically check for any signs of contact pitting or carbon buildup if the relay is switching heavy inductive loads frequently.
Product Technical Description
The MVAX12B1CA0753A belongs to the “M-Series” of Alstom numerical and auxiliary relays. It is built for longevity and stability, utilizing a robust hinged armature mechanism that ensures high contact pressure and low contact resistance. The “12” in the model name indicates the specific contact and case configuration, while the “B1” designation identifies the specific coil rating and resetting characteristics. This relay is engineered to withstand the high electromagnetic interference and vibration levels found in industrial switchgear, making it a “fit and forget” solution for critical control loops.
Q&A (Common Questions)
Q: Can this relay be used for AC voltages? A: This model is specifically rated for 110/125V DC. Using it on an AC circuit may cause the relay to chatter or fail to operate correctly.
Q: Is there a visual indicator for the relay status? A: Yes, the MVAX series typically includes a mechanical flag indicator that changes color (usually to red) when the relay is in the operated position.
Q: What is the difference between MVAX 11 and MVAX 12? A: The primary difference is the number of available contacts and the case size; the MVAX 12 offers a higher contact density for more complex signaling requirements.
Q: Does this relay require external resistors for the 125V DC supply? A: No, the “CA0753A” internal coil is designed to handle the full range of 110V to 125V DC without the need for external dropping resistors.
Similar Model Recommendations
- GEC Alsthom MVAX 11 (Fewer contacts variant)
- GEC Alsthom MVAX 31 (Hand-reset version)
- GEC Alsthom MVAA (Standard auxiliary relay series)
- GE Alstom MVAX12B1CA0751A (Different voltage variant)
- GEC Alsthom MVAJ (High-speed tripping relay variant)
For technical support or a price quote on the GEC Alsthom MVAX12B1CA0753A, please visit our product catalog or contact our sales office.
