8 Common Transformer Problems and Solutions

Transformer problems can cause it to fail and disrupt a power supply network. In the worst of cases, it could even go up in flames. Engineers overseeing its operation would prevent that by correctly identifying the problems and their early signs. Below, we show you how to do it and the actions to take.

What Causes a Transformer to Fail?

Transformer failure can have various causes. One of them, and one of the most significant, is incorrect use. A transformer will fail if you overload it or subject it to an application or environment not meant to operate.

Lack of proper maintenance is another primary reason for failure. If not regularly checked, various parts could get damaged, leading to catastrophic incidents such as hot spots and short circuits.

Age-related wear also eventually damages components. For instance, the insulation may degrade and expose the windings after many years. Problems may occur if serviceable parts are not changed (or the entire unit is not replaced on time).

What Happens When a Transformer Fails?

Several things can happen when a transformer fails. If the problem is minor, the device may only deviate from its operational specifications. If the issue is more severe, failure signs may include increased noise and vibrations.

Worse situations could see the transformer spark or overheat to a level where it catches fire. As you’ll learn in the following section, understanding transformer failure modes and their causes can help avert a disaster.

Common Transformer Problems

Transformer problems include those caused by electrical faults, contamination due to ingress, and physical damage. This list describes the most common issues and their possible causes.

Overheating

A transformer generates heat during operation, which is normal and within limits. Sometimes, the heat is way too much. Temperature spikes mainly result from short circuits or a failed cooling system. This problem could cause components to fail and combustible materials to catch fire.

Insulation Breakdown

Insulation isolates conductive parts to prevent short circuits and other dangers. If it breaks down, it no longer serves this function. This type of damage is one of the most common problems. Insulation breakdown typically occurs in the windings, causing partial discharge and other issues.

Moisture Ingress

Moisture should not get into the transformer. It causes parts to rust and paper-based insulation to deteriorate. If the transformer contains oil, the moisture would contaminate it, reducing its cooling and insulation properties.

Overloading

Overloading exceeds the transformer’s specified limits, subjecting it to electrical stress. Each type has rated voltage, current, and other specifications that, when exceeded, lead to severe issues, including fires.

Short Circuits

Short circuits occur when insulation fails, and the high voltages in the windings send current in the wrong paths between them or them and other parts. The increased current could cause overheating, sometimes dangerous, if not detected on time.

Oil Contamination

Contamination occurs when water and other materials enter the insulating oil; these contaminants lower the oil’s ability to isolate or dissipate heat. Various tests, such as the breakdown voltage test, help detect the presence of these pollutants during routine maintenance.

Corrosion

Parts corrode if constantly exposed to moisture and chemical elements. Various parts are prone to this problem. They include the enclosure, taps, bushings, and the coil or windings. Insulation failure can cause electrical faults in the conductive parts. If located on the tank walls, corrosion forms a sludge that contaminates the oil.

Mechanical Damage

Mechanical damage includes raptured bushings, deformed enclosures, compromised welds, cracks that leak oil or allow ingress of materials, broken parts, and more. It can have various causes, such as vibrations, impact forces, etc. This type of damage is physical and easily identifiable.

Troubleshooting Transformer Problems

Various measures can help diagnose and troubleshoot transformer problems. They include visual examinations and electrical or other tests. After identifying the problem, the proper steps are taken to correct it, such as changing the affected component. They include:

Visual Inspection

Regular inspections identify visible damage like corroded or loose contacts, deformations, cracks, leaks, stripped paint, broken parts such as bushings, or reduced oil levels. Taking preventative measures can help avoid further or accelerated damage.

Electrical Tests

Electrical tests identify most transformer problems. That’s because most issues, including short circuits, partial discharge, and overheating, are related to excess voltage or current. Some tests check the oil and solid insulation for damage.

Thermal Imaging

Thermal imaging involves using an infrared camera to detect hot spots. This technique identifies insulation and primary or secondary windings issues. It’s a more straightforward method when diagnosing overheating or short-circuit faults.

How to Prevent Transformer Problems

Various measures can help prevent transformer problems, saving power systems from prolonged downtimes or the need for major replacements. They include the following:

Scheduled Servicing

Users must schedule maintenance sessions to inspect the device’s operation and components. During these sessions, testing experts check crucial parts and systems for failure or its possibility, carry out repairs, and document their findings for future reference.

Load Management

Overloading is one of the most common causes of transformer failure. Each device has rated voltage, current, and other specifications that, when exceeded, can cause severe failure, including fires. Using the device within its rated limits helps avoid that.

Using Monitoring Systems

Advanced monitoring systems and equipment help detect failure signs like increased noise, emitted gases during faults, or a sudden temperature rise. These include remote systems that use sensors and IoT equipment to let workers watch over entire systems from one central location.

Retrofits and Upgrades

Older transformers could have dated parts that are prone to specific issues and failure modes. Retrofitting them would help solve that.

If the entire unit is an older technology, upgrading it to a modern type would be a better decision, especially if it’s over a few decades old.

Modern technologies include better insulation materials that can withstand higher temperatures or better core materials that offer increased efficiency.

Smart transformers with electronic diagnostic and monitoring systems are available today. These enhance problem detection, making them safer and more long-lasting.

Conclusion

Several issues can cause transformer failure, leading to safety risks or an outage. If the damage is severe, the resulting losses can be catastrophic, ranging from replacement costs to downtimes and lost production time. Addressing issues early enough can help prevent them from escalating and extend the device’s lifespan.