Dry-type Transformers Encountering External Short Circuits: The Internal Damage You Can't See

2500 kva dry type transformer plays a core role in the power system, but the short-circuit current caused by a circuit fault is like a sudden shock wave. When this abnormally powerful current surges into the coil instantly, the internal structure is subjected to enormous stress. This is not simply a matter of heat generation; it directly affects the lifespan of the equipment.

How powerful the electrodynamic force tears the coil

At the moment a short circuit occurs, the 150kva dry type transformer device will generate tens or even hundreds of times the normal electrodynamic force. These forces are divided into axial and radial forces.

• Coil Deformation: The enormous radial force attempts to push the winding outward. If the support structure is not stable enough, irreversible bulging will occur in the copper or aluminum foil windings.

• Insulation Wear: The axial force causes the coil to vibrate violently up and down. This high-frequency shaking rubs against the solid insulation material, causing the insulation layer to thin.

• Loosening of Support Components: Frequent small current fluctuations, though difficult to detect with the naked eye, will damage the pads and clamping devices over time.

The Fatal Damage of Instantaneous High Temperatures to Insulation Materials

Current overload not only brings mechanical shock but is also accompanied by rapid temperature rise. Because dry-type circuit breakers primarily rely on natural air convection or fan cooling, heat dissipation is limited.

The windings reaching extremely high temperatures in a short time can cause thermal aging of the insulating media, such as epoxy resin. This damage is insidious; even after the fault is cleared, the surface may appear fine, but the internal insulation performance has already been compromised. This "hidden damage" is often the trigger for future sudden breakdown faults.

Everyday Ideas for Improving Short-Circuit Resistance

To extend the service life of the 15kva dry type transformer series, prevention is better than cure. Checking the tightness of fasteners is crucial; even a slight loosening can be amplified by short-circuit forces. Regularly observing the winding surface for carbonization is also the most direct way to determine overheating. Simultaneously, optimizing the setting logic of the upstream circuit breakers can allow the equipment to escape danger earlier before a disaster strikes.