Dry-type Transformers: Analysis Of Their Overload Capacity Limits And Performance

Under high current or short-term heavy load conditions, the cast coil transformer may still operate beyond its rated capacity. In most cases, its short-term overload capacity is set according to design and manufacturing specifications; for some models of the cast resin distribution transformer, a short-term overload to 150% of the rated load for approximately 30 minutes is within the permissible range.

Overload capacity depends on several key parameters. The heat resistance grade of the insulation materials used in the windings and core directly affects its ability to withstand temperature rise. Higher grade insulation materials allow fans or air-cooled systems to dissipate heat more effectively during overloads, enabling the structural design to allow higher currents to pass without damaging the cast resin dry type transformer manufacturers itself.

The cooling method and installation environment of the cast resin type transformer are also extremely critical. When using forced air cooling (or a well-ventilated location), heat can be dissipated rapidly, making it possible to achieve higher overloads in a short time. Conversely, if the ambient temperature is high, ventilation is poor, or humidity is high, its overload tolerance will decrease significantly.