The GEC Alsthom MVTU13D1AA0751H is a high-precision voltage protection relay from the MVTU series. This digital/static relay is designed to monitor system voltage levels and provide critical protection functions such as under-voltage, over-voltage, or neutral voltage displacement (residual voltage) monitoring. As part of the GEC Alsthom (now legacy GE/Alstom) protection family, the MVTU series is renowned for its accuracy, reliability, and modular construction in power distribution and industrial electrical systems.

 

Product Parameters and Technical Specifications

The MVTU13D1AA0751H is engineered to integrate seamlessly into standard protection schemes.

• Model Number: MVTU13D1AA0751H
• Series: MVTU (Voltage Protection)
• Protection Functions: Programmable for Over-voltage (59) or Under-voltage (27) logic.
• Rated Voltage (Vn​): Typically 110V AC (Standard PT secondary output).
• Auxiliary Supply: 110-125V DC (indicated by the specific suffix, though variants exist for 24V or 220V).
• Setting Range: Adjustable thresholds for pickup and dropout.
• Time Delay: Adjustable definite time delay for coordinated tripping.
• Contacts: High-capacity changeover contacts for alarm and trip circuits.

 

Product Datasheet Summary

The MVTU13D1AA0751H datasheet highlights its solid-state electronic design, which offers significantly higher accuracy and lower burden on the voltage transformers compared to older electromagnetic relays. The “13” in the model code typically designates a single-phase unit, while the “D” indicates a specific definite time characteristic. The unit features a front-facing user interface with rotary switches or potentiometers for precise setting of voltage thresholds and time delays. It is housed in a standard M-size modular case, facilitating the “draw-out” feature for rapid maintenance and testing.

 

Country of Origin

This protection module was manufactured in the United Kingdom, specifically at the Stafford works, which was a global center for GEC Alsthom protection and control engineering.

 

Application Fields

The MVTU series is widely utilized across the power grid and heavy industry:

• Substation Automation: Monitoring busbar voltages and providing interlock signals.
• Generator Protection: Detecting under-voltage conditions that could lead to instability.
• Industrial Motors: Protecting large synchronous motors from voltage dips that could cause stalling or overheating.
• Renewable Energy: Ensuring grid-tie voltage levels remain within statutory limits for wind and solar farms.

 

Product Usage Instructions

1. Mounting: Install the relay case into the panel cutout. Ensure the terminal block wiring is secure before sliding the relay module into the case.
2. Settings: Calculate the required pickup voltage based on your system’s nominal Vn​. Adjust the front-panel dials to the desired voltage threshold and time delay.
3. Testing: Utilize the MMLG test block (if installed) or secondary injection points to simulate a voltage fault. Verify that the relay targets (flags) operate and the output contacts change state.
4. Maintenance: Regularly inspect the relay for dust accumulation. Since this is a static relay, no internal lubrication is required, but periodic calibration checks are recommended.

Technical Description

The MVTU13D1AA0751H operates by rectifying and filtering the incoming AC voltage signal. This signal is compared against a highly stable internal reference voltage. If the measured voltage exceeds or falls below the user-defined threshold, an internal timing circuit is initiated. Once the set time delay expires, an output slave relay is energized. The use of CMOS technology in the timing circuit ensures excellent repeatability and immunity to temperature fluctuations, which is a significant upgrade over traditional RC-timing circuits.

 

Q&A – Frequently Asked Questions

Q: What is the significance of the “H” at the end of the model number? A: In GEC Alsthom nomenclature, the final letter often refers to the case size or the specific hardware revision level. “H” typically indicates a standard horizontal modular case configuration.

Q: Can this relay be used for 3-phase protection? A: The MVTU13 is a single-phase unit. For 3-phase protection, you would typically use three MVTU13 units or a single MVTU11/12 variant designed for multi-phase monitoring.

Q: Is this relay compatible with modern SCADA systems? A: As a legacy static relay, the MVTU13D1AA0751H provides “dry” contact outputs for binary inputs to a RTU or PLC. It does not have native digital communication protocols like IEC 61850.

Q: Where can I find more MVTU series relays and parts? A: You can find the GEC Alsthom MVTU13D1AA0751H and other legacy GEC Alsthom protection modules through professional industrial automation and power system suppliers.

 

Recommended Similar Models

1. GEC Alsthom MVTU11 – Three-phase version for comprehensive busbar monitoring.
2. GEC Alsthom MVTT14 – Voltage-controlled time-delay relay.
3. GEC Alsthom METI – Legacy induction disc type voltage relay for older installations.
4. Alstom P12x Series – The modern numerical successor to the MVTU static series.
5. GEC Alsthom MCAA – Auxiliary relay often used in conjunction with MVTU for signal multiplication.