Transformers are the heart of any power system. Whether you’re operating a grid substation, a manufacturing plant, or a large commercial facility in the UAE, keeping transformers healthy is critical to avoiding costly downtime and equipment failure. One of the earliest and most important warning signs of internal issues in a transformer is the presence of hydrogen in its insulating oil.
Hydrogen is one of the first gases produced when faults occur inside transformers, and monitoring its level can tell you a lot about what’s happening beneath the surface. In this article, we’ll explain what causes hydrogen formation, why dissolved gas analysis (DGA) is essential, how hydrogen levels are detected, and how companies like Star Freight Trading support transformer reliability through oil supply, testing, and monitoring solutions.
What Causes Hydrogen Formation in Transformer Oil
Transformer oil serves two main purposes: it provides insulation between energized components and acts as a coolant to dissipate heat. Under normal operating conditions, the oil remains stable. However, when electrical or thermal stress occurs, the oil and insulation materials can decompose, releasing gases — with hydrogen being one of the most common.
Main causes of hydrogen generation
-
Partial Discharges
Small, localized electrical discharges within voids or impurities in the insulation can cause the breakdown of oil molecules. These partial discharges release free hydrogen atoms, which combine to form hydrogen gas. -
Thermal Faults
Excessive heat caused by overloading, poor cooling, or localized hotspots can thermally decompose the oil and cellulose insulation. Hydrogen is typically one of the first gases produced during this process. -
Arcing Faults
In more severe cases, electrical arcing can rapidly break down oil molecules, creating a surge in hydrogen and other fault gases such as acetylene and ethylene. -
Stray Gassing
Even without major faults, certain chemical reactions within the oil can slowly produce hydrogen over time. This can be influenced by oil composition, temperature, and contact with metal surfaces. -
Moisture and Contamination
Water and impurities accelerate chemical degradation. Moisture in particular lowers the oil’s dielectric strength and promotes gas formation under stress.
The UAE environment factor
In the UAE, ambient temperatures can exceed 45°C for much of the year. Transformers under these conditions experience higher oil temperatures and heavier cooling demands. Without proper monitoring and maintenance, the combination of heat, dust, and moisture can lead to faster oil degradation and increased hydrogen production. Our Services
The Importance of Dissolved Gas Analysis (DGA)
Hydrogen alone doesn’t damage a transformer, but its presence signals something deeper: a potential electrical or thermal fault. Dissolved Gas Analysis (DGA) is the most effective tool for detecting and understanding these issues before they become serious.
What DGA does
DGA measures the concentration of gases dissolved in transformer oil — hydrogen, methane, ethane, ethylene, acetylene, carbon monoxide, and others. By analyzing both the individual gases and their ratios, engineers can identify the type and severity of internal faults.
For example:
-
A slow increase in hydrogen may suggest partial discharge activity.
-
A combination of hydrogen and methane could indicate low-temperature overheating.
-
The presence of acetylene along with hydrogen often points to arcing or high-temperature faults.
Benefits of DGA
-
Early Fault Detection: Catching a problem early prevents catastrophic transformer failure.
-
Trend Analysis: Comparing gas levels over time helps distinguish between normal aging and emerging faults.
-
Condition-Based Maintenance: DGA allows you to move from scheduled maintenance to predictive maintenance — repairing only when data shows a clear need.
Why it’s vital in the UAE
With high operating loads and environmental stress, transformers in the UAE are more prone to oil breakdown. Implementing regular DGA testing ensures transformers stay reliable in demanding conditions. Star Freight Trading provides both DGA testing services and equipment to help UAE industries maintain this level of oversight.
How to Detect Hydrogen Levels in Transformers
Hydrogen detection can be done through two main approaches: laboratory analysis and online monitoring.
Laboratory DGA
This is the traditional method. A small oil sample is drawn from the transformer, and gases are extracted and measured using gas chromatography. This provides precise readings for hydrogen and other gases. Results are compared to previous samples to identify trends or anomalies.
Online Hydrogen Monitoring
For critical transformers, online sensors are increasingly preferred. These devices continuously measure hydrogen levels in real time. If the gas concentration rises suddenly, alerts are triggered, allowing for immediate investigation.
Online sensors are particularly useful in:
-
Utility substations and grid transformers
-
High-capacity industrial sites
-
Facilities where power interruption is costly or unsafe
Star Freight Trading offers advanced hydrogen monitoring systems suited to the UAE’s power and industrial sectors. These sensors provide 24/7 visibility into transformer health, allowing operators to respond quickly to any abnormal rise in gas levels.
Interpreting Results
-
Normal: 10–50 ppm hydrogen may be typical for older units.
-
Caution: 50–100 ppm suggests partial discharge or low-level thermal faults.
-
Alert: Above 100 ppm or rapidly rising hydrogen levels require inspection.
The key isn’t only the absolute number, but also how fast hydrogen levels increase. A steady climb is more concerning than a stable reading. Our Products
Effects of High Hydrogen Concentration on Transformer Health
A high concentration of hydrogen in transformer oil is a warning sign that something is happening inside the unit. Ignoring it can lead to serious damage.
Key impacts
-
Insulation Breakdown
Hydrogen formation means oil and cellulose are decomposing. This degradation weakens the insulation, increasing the chance of a dielectric failure. -
Reduced Dielectric Strength
Gas bubbles within the oil reduce its ability to insulate properly. This can result in partial discharges escalating into full electrical breakdowns. -
Accelerated Aging
Hydrogen generation often accompanies heat and chemical reactions that accelerate overall transformer aging. -
Fault Escalation
What begins as a minor thermal fault can develop into arcing if hydrogen and other gases continue to rise. -
Operational and Financial Risk
Transformer failure can halt operations, cause extensive equipment damage, and lead to major repair costs. In industries such as power distribution, oil and gas, and manufacturing, the financial impact can be significant.
UAE considerations
Because of the region’s high load factors and ambient heat, UAE transformers are more likely to operate near their design limits. Elevated hydrogen levels should be treated as an urgent signal to investigate and act before damage spreads.
Preventive Maintenance and Gas Monitoring Techniques
Preventing excessive hydrogen formation starts with consistent monitoring and good transformer maintenance practices.
1. Regular Oil Testing
Perform DGA and oil quality tests at regular intervals. For less critical transformers, testing every six to twelve months may be enough. For essential units, quarterly testing is safer.
2. Trending and Record Keeping
Maintain detailed records of gas levels, oil condition, and operating data. A well-kept trend chart helps detect even minor changes early.
3. Oil Purification and Degassing
If gas or moisture levels rise, purify the oil using vacuum filtration and degassing systems. This restores dielectric strength and extends oil life. Star Freight Trading supplies and operates oil purification units throughout the UAE, ensuring transformers stay within safe operating limits.
4. Load and Temperature Management
Avoid continuous overloading. Keep cooling fans, radiators, and oil pumps clean and operational to control temperature.
5. Online Gas Monitoring
Install hydrogen or multi-gas sensors on critical transformers. These systems provide continuous, real-time visibility and can trigger alarms when gas levels spike.
6. Insulation and Component Inspection
If DGA or monitoring data suggests a problem, inspect bushings, windings, and tap changers for partial discharges or overheating. Address the root cause before it progresses.
7. Training and Procedure Control
Ensure personnel handling oil sampling and testing follow best practices. Contaminated samples or poor handling can lead to false readings.
By combining these steps, UAE utilities and industries can significantly extend transformer life and minimize unplanned outages.
Industry Standards for Hydrogen Detection and Safety
To ensure consistency and reliability, international standards define how gases in transformer oil should be sampled, analyzed, and interpreted. Adhering to these standards ensures accurate results and safe operation.
Key standards
-
IEC 60567: Defines methods for sampling and analyzing dissolved gases in insulating liquids.
-
IEC 60599: Provides guidelines for interpreting DGA results.
-
IEC 60296: Covers requirements for new insulating oils.
-
IEEE C57.104: Offers interpretation criteria for gas generation in oil-immersed transformers.
UAE companies should ensure their service providers and equipment comply with these standards. This ensures results are globally recognized and actionable.
Safety thresholds
While exact limits depend on transformer type and history, most operators treat hydrogen concentrations above 100 ppm as a warning level. A rapid increase, even from a lower baseline, is also a red flag.
Regular calibration of testing and monitoring equipment is essential to maintain accuracy. A small measurement error could mean overlooking an emerging fault.
UAE industry practice
Most UAE utilities and major industrial facilities now integrate DGA and hydrogen monitoring into their asset management systems. They also partner with trusted suppliers like Star Freight Trading for oil testing, equipment, and ongoing maintenance support to ensure compliance with IEC and IEEE standards.
Hydrogen in transformer oil is more than a chemical curiosity — it’s an early warning signal of potential failure. Understanding how and why hydrogen forms, and how to monitor it effectively, can mean the difference between smooth operation and an unexpected outage.
For UAE industries and utilities, the stakes are high. High temperatures, heavy loads, and demanding conditions make transformers more vulnerable to insulation breakdown and gas formation. Regular DGA testing, online hydrogen monitoring, and proper oil maintenance are the best defenses.
Star Freight Trading supports UAE operators with high-quality transformer oils, testing services, and gas monitoring solutions that meet international standards. By implementing preventive maintenance and staying alert to changes in hydrogen levels, you can protect your assets, extend transformer life, and maintain reliable power performance across every operation.
Frequently Ask Questions
1. What does hydrogen in transformer oil indicate?
Hydrogen in transformer oil usually signals early insulation breakdown, partial discharges, or overheating inside the transformer. It’s one of the first gases produced when faults begin to develop.
2. Why is hydrogen monitoring important for transformers in the UAE?
The UAE’s high ambient temperatures and heavy electrical loads increase transformer stress. Monitoring hydrogen levels helps detect problems early, preventing costly failures and outages.
3. How are hydrogen levels detected in transformer oil?
Hydrogen levels are measured using Dissolved Gas Analysis (DGA) or online hydrogen sensors. DGA involves laboratory testing of oil samples, while online sensors provide real-time readings.
4. What is a safe hydrogen level in transformer oil?
Hydrogen levels below 50 ppm are typically considered normal. Readings between 50–100 ppm suggest early fault activity, while levels above 100 ppm usually require immediate investigation.
5. How can high hydrogen levels be reduced?
Reducing hydrogen levels involves identifying and fixing the root cause, such as overheating or partial discharge. Oil purification, degassing, and proper load management can also help stabilize gas levels.
6. How can Star Freight Trading help with transformer maintenance?
Star Freight Trading provides transformer oils, DGA testing, and hydrogen monitoring systems across the UAE. Their support helps operators maintain compliance, improve reliability, and extend transformer lifespan.