{"id":96557,"date":"2026-10-12T17:33:03","date_gmt":"2026-10-12T15:33:03","guid":{"rendered":"https:\/\/www.lecosinus.fr\/?p=96557"},"modified":"2026-10-21T16:10:31","modified_gmt":"2026-10-21T14:10:31","slug":"why-is-my-transformer-making-noise","status":"publish","type":"post","link":"https:\/\/www.lecosinus.fr\/en\/pourquoi-mon-transformateur-fait-du-bruit\/","title":{"rendered":"Why is my transformer humming?"},"content":{"rendered":"

A humming transformer isn\u2019t necessarily defective. An electrical transformer<\/a> naturally produces a slight humming sound when it\u2019s operating. The laminations in the magnetic circuit expand and contract very slightly in time with the alternating current. This noise should remain low, steady, and consistent. If it suddenly becomes louder, irregular, or is accompanied by an unusual odor, overheating, or significant vibrations, an inspection is necessary. \n\n\n\nTranslated with DeepL.com (free version)<\/p>\n\n\n\n

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Where does the normal noise come from?<\/strong><\/h2>\n\n\n\n

The noise comes mainly from the magnetic core. Under the influence of the alternating magnetic flux, the metal laminations expand and contract very slightly\u2014a phenomenon known as magnetostriction. These movements create small vibrations that are transmitted to the chassis.<\/p>\n\n\n\n

On a 50-Hz power grid, the humming sound is often perceived at around 100 Hz, because the core deforms twice per cycle. A low-pitched, continuous sound that has remained unchanged since the equipment was put into service is therefore generally normal.<\/p>\n\n\n\n

Pourquoi le bruit d’un transformateur peut-il augmenter ?<\/strong><\/h2>\n\n\n\n

Too heavy a load <\/strong><\/h3>\n\n\n\n

As the load increases, the current flowing through the windings also increases. The higher the load, the greater the current in the windings. Electromagnetic forces can then amplify certain vibrations. In fact, the electromagnetic forces between the windings intensify and cause the windings to vibrate, which increases the noise. If this increase in noise is accompanied by unusual heating, it may indicate an overload or improper sizing. See also our guide to calculating the required power of a transformer<\/a>. <\/strong><\/p>\n\n\n\n

Loose fasteners or a resonance<\/strong><\/h3>\n\n\n\n

Over time, vibrations can cause a screw, a cover, a sheet metal panel, or a bracket to come loose. A base that is too rigid can also transmit noise to walls and floors. A mechanical inspection performed by a professional can identify the affected component and determine whether vibration-damping measures are necessary. <\/p>\n\n\n\n

Une alimentation<\/strong> ou<\/strong> un<\/strong> refroidissement<\/strong> anormal<\/strong><\/h3>\n\n\n\n

Excessively high voltage, harmonics, or poor-quality power can alter the typical noise. This is because the flux in the core is proportional to the voltage: excessively high voltage increases it and thus accentuates the magnetostriction. The reference values are listed on the transformer nameplate<\/a>.<\/p>\n\n\n\n

In transformers equipped with forced ventilation, noise can also be caused by a dirty or worn-out fan. Insufficient ventilation increases thermal stress; our article on overheating and insulation classes<\/a> provides further information on this topic.<\/p>\n\n\n\n

Aging or an internal defect<\/strong><\/h3>\n\n\n\n

Deteriorated insulation, a damaged winding, or a loose internal component can cause an irregular humming, clicking, or crackling sound. These sounds should not be dismissed as a mere nuisance. <\/p>\n\n\n\n

What signs should raise a red flag?<\/strong><\/strong><\/h2>\n\n\n\n

Have the installation inspected promptly if you notice: <\/p>\n\n\n\n