The ABB HESG 216443 R6 (Model DIX 111a-5) is a high-precision differential protection relay designed for the rapid detection of internal faults in electrical power systems. This unit is part of the DIX series, specialized in protecting power transformers, generators, and busbar sections. By comparing the currents entering and leaving a protected zone, the DIX 111a-5 identifies phase-to-phase and phase-to-earth faults with high sensitivity while remaining stable during external “through-fault” conditions.

Product Parameters and Technical Specifications

This relay is built to meet high-voltage substation standards, featuring a specialized low-voltage auxiliary supply configuration.

• Model Number: HESG 216443 R6 / DIX 111a-5
• Protection Type: Differential Protection (87)
• Rated Current (In​): 5A AC (Standard CT secondary compatible)
• Rated Frequency (fn​): 50Hz
• Auxiliary Voltage (Uh​): 20/30V DC (Low-voltage DC station battery or specialized power supply)
• Response Time: Fast-acting tripping logic (typically sub-cycle to 30ms)
• Enclosure: Modular industrial housing for rack or panel mounting

 

Product Datasheet Summary

The DIX 111a-5 datasheet highlights its high-stability characteristics, achieved through internal filtering that ignores DC offsets and harmonic inrush currents. The “HESG 216443 R6” designation refers to the specific hardware revision and build-standard within ABB’s manufacturing system. The relay features adjustable pickup thresholds and slope settings to compensate for CT ratio mismatches and transformer tap-changer positions. Its low-voltage auxiliary rating (20/30V) makes it unique for specific control architectures or smaller-scale industrial power distribution units.

 

Country of Origin

This precision protection module was manufactured in Switzerland, reflecting ABB’s European heritage in high-end power transmission and distribution engineering.

 

Application Fields

The DIX series is widely implemented in critical infrastructure:

• Power Transformers: Protecting windings against internal short circuits.
• Small to Medium Generators: Providing primary protection in industrial co-generation plants.
• Bus-Tie Protection: Monitoring the balance between different busbar sections in a substation.
• Industrial Feeders: Used in specialized manufacturing plants with sensitive 50Hz power requirements.

 

Product Usage Instructions

1. Mounting: Ensure the relay is mounted in a clean, dry environment within the control cabinet.
2. CT Connection: Properly wire the current transformer secondaries to the differential input terminals. Ensure correct polarity (P1/P2 and S1/S2) to avoid “nuisance” tripping due to perceived imbalance.
3. Power Supply: Connect a stable 20V or 30V DC auxiliary supply to the Uh​ terminals. Verify the voltage level before energizing to prevent damage to the internal logic boards.
4. Testing: Perform a “Through-Fault Stability Test” and an “Internal Trip Test” using secondary injection equipment to verify the relay’s slope and pickup settings.

 

Technical Description

The DIX 111a-5 operates on the Merz-Price circulating current principle. Under normal conditions, the current entering the zone equals the current leaving it (Iin​−Iout​=0). If a fault occurs inside the zone, the vector sum of the currents is no longer zero, creating a “differential” current (Id​). The relay processes this Id​ against a percentage-bias curve; it will only issue a trip command if the differential current exceeds a set percentage of the through-current, effectively preventing false trips during heavy load or external faults where CTs might partially saturate.

 

Q&A – Frequently Asked Questions

Q: Why does this model use a 20/30V auxiliary supply? A: While many substation relays use 110V or 220V DC, the 20/30V version is often found in older European industrial standards or systems where control logic is powered by specialized low-voltage battery banks.

Q: Can this 50Hz relay be used on a 60Hz system? A: It is not recommended. The internal filters and timing logic are tuned for 50Hz. Using it on 60Hz may result in inaccurate pickup levels and degraded stability during external faults.

Q: What is the “R6” in the part number? A: This refers to the specific Revision level. It indicates that this version includes all previous hardware improvements and component updates for this specific model line.

Q: Where can I source the DIX series and other ABB protection parts? A: You can find the ABB HESG 216443 R6 and other legacy or current ABB protection modules through specialized industrial automation inventory providers.

 

Recommended Similar Models

1. ABB DIX 110 – A simplified version for less complex differential schemes.
2. ABB RET 670 – The modern numerical successor to the DIX series for transformer protection.
3. ABB DIX 111b – A variant with different auxiliary voltage ratings or contact configurations.
4. ABB RADSB – A related high-speed busbar differential protection system.
5. ABB HESG 442 – Auxiliary power supply units often used to provide the Uh​ for DIX relays.