The GEC Measurements VAU41RF1HL3601BA5 is a high-reliability auxiliary protection relay designed for voltage monitoring and signal multiplication in power systems. As a key component in the VAU series, this static (solid-state) relay provides precise under-voltage or over-voltage detection. It is commonly used as a logic element to initiate tripping sequences, interlock switching operations, or trigger alarms when system voltage deviates from predefined safety limits.

 

Product Parameters and Technical Specifications

This relay is engineered to maintain high accuracy and stability across industrial temperature ranges.

• Model Number: VAU41RF1HL3601BA5
• Brand: GEC Measurements (legacy Alstom / GE Grid Solutions)
• Relay Type: Static Voltage Protection Relay
• Configuration: Single-element / Single-phase monitoring
• Rated Voltage (Vn​): Typically 110V AC (configurable for standard PT secondaries)
• Auxiliary Supply: 110V – 125V DC (indicated by the “H” coding in the suffix)
• Contact Arrangement: Multi-contact output for simultaneous trip and alarm signals
• Enclosure: Standard M-series draw-out modular case

 

Product Datasheet Summary

The VAU41RF1HL3601BA5 datasheet emphasizes its solid-state design, which offers a significant upgrade over older electromagnetic types by providing lower burden on the instrument transformers and superior resistance to vibration. The “RF” designation typically indicates a specific reset and flag configuration, ensuring that maintenance personnel can easily identify which relay initiated a system shutdown. The unit features an adjustable setting range for both the voltage pickup level and the definite time delay, allowing for perfect coordination with other protection devices in the network.

 

Country of Origin

This protection module was manufactured in the United Kingdom, originating from the Stafford center of excellence for GEC Measurements.

 

Application Fields

The VAU series is an essential safeguard in numerous electrical infrastructures:

• Utility Substations: Monitoring busbar health and providing under-voltage protection for distribution feeders.
• Industrial Power Plants: Protecting large AC motors from “brownout” conditions that could lead to winding damage.
• Railway Traction: Ensuring the overhead line voltage stays within operational limits for locomotive power.
• Marine Systems: Managing the voltage stability of shipboard microgrids and generator sets.

 

Product Usage Instructions

1. Mounting: Insert the relay module into its designated horizontal or vertical case. Ensure the rear connectors are firmly seated to engage the CT/PT shorting links.
2. Settings: Adjust the front-panel potentiometers to the required voltage threshold. Set the time delay to prevent “nuisance” trips caused by momentary voltage transients.
3. Wiring Check: Verify that the auxiliary DC supply is connected with the correct polarity to the specified terminals on the rear of the case.
4. Flag Reset: After a fault has been cleared, the mechanical or LED flag must be manually reset to prepare the relay for the next monitoring cycle.

Technical Description

The VAU41RF1HL3601BA5 operates by sampling the incoming AC voltage and rectifying it to a DC level for internal comparison. It uses a high-stability reference circuit to determine if the input has crossed the user-set threshold. Once the condition is met, a precision timer starts; if the fault persists beyond the set time, the output slave relay is energized. This architecture ensures that the relay is immune to frequency variations and harmonic distortion, providing a clean and reliable trip signal only when a genuine voltage anomaly occurs.

 

Q&A – Frequently Asked Questions

Q: What is the benefit of the “Static” architecture in this VAU model? A: Static relays have no moving parts in the measuring circuit, which means they are not subject to mechanical wear, have faster reset times, and offer much higher seismic and vibration resistance than induction-type relays.

Q: Can this relay be tested without disconnecting the system? A: Yes, if the case is equipped with a compatible GEC MMLG test block, you can isolate the trip circuits and inject test signals while the primary system remains live.

Q: Does the VAU41 support communication protocols like Modbus or DNP3? A: No, this is a legacy static relay providing hard-wired contact outputs. For digital communications, it would typically be paired with a modern RTU or upgraded to a numerical relay like the MiCOM series.

Q: Where can I find more VAU series relays and compatible cases? A: You can find the GEC Measurements VAU41RF1HL3601BA5 and other specialized protection components through professional industrial automation and power grid suppliers.

 

Recommended Similar Models

1. GEC Measurements VAU11 – A variant designed for different voltage ranges or logic configurations.
2. GEC Measurements MVTU – A dedicated voltage protection series with slightly different timing characteristics.
3. GEC Measurements MCAA – An auxiliary relay often used alongside the VAU for additional contact outputs.
4. Alstom MiCOM P12x – The modern numerical successor to the VAU static series.
5. GEC Measurements MVAA – High-speed tripping relay frequently used in master trip schemes with VAU relays.