Transformer Maintenance: What Are the Warning Signs?

At Le Cosinus, a French manufacturer of electrical transformers for nearly 80 years, we have always made it a point of honour to guarantee the reliability, durability and performance of electrical installations. We know that a well-maintained transformer used in good conditions will prevent breakdowns, limit costly shutdowns and above all, guarantee the safety of your teams' equipment. Preventive maintenance is therefore a key investment in preventing malfunctions, but how do you know when it is necessary to intervene? There are some warning signs that can alert you to the condition of your transformer.

Preventive Maintenance

You shouldn't wait until you have warning signs to maintain your transformer. For dry-type transformers, for example, dusting will prevent a reduction in the cooling of the product and therefore excessive degradation of its insulation. Another crucial point is that tightening the electrical connections twice a year if possible is essential to keep a transformer in working order for decades.

1. Abnormal heating

One of the first visible signs of transformer degradation is excessive heating. If the temperature rises above the usual thresholds, it may be an important warning. There are several causes for this, such as: 

• Persistent overload: A transformer that operates at too high load levels. 

• Cooling problems: Dusty environment clogged ventilations. Supply voltage that has become too high (change in supply voltage) or the appearance of harmonics following the installation of polluting loads. 

2. Unusual noises

Un transformateur fonctionnant correctement émet un bourdonnement régulier et stable. Cependant, des bruits inhabituels tels que des grésillements ou des vibrations excessives peuvent être le signe de problèmes électriques sous-jacents. Ces bruits peuvent indiquer des défauts d’isolation ou des éléments desserrés à l’intérieur du transformateur. Ne pas tenir compte de ces bruits peut entraîner des défaillances, pouvant affecter la performance la sécurité du système et finalement une panne. 

3. Suspicious smells

Smell is another indicator. If you detect a smell of burning, heated plastic or solvent, it is imperative to intervene immediately. This type of odour is often linked to advanced degradation of the insulation, localised heating or electrical ignition. These signs are often a harbinger of major breakdowns, or even fire hazards. Never ignoring this type of alert can save you from serious consequences. It is then imperative to shut down the transformer in order to carry out an analysis.

Degradation of electrical performance

Anomalies in electrical performance are also important warning signs. If you notice a voltage drop, unusual fluctuations, or phase imbalances, it may reflect an internal weakness of the transformer. Rigorous performance monitoring, including stress testing and isolation measures, is necessary to detect these drifts and intervene before problems spread.