Maintenance of dry type transformer

Epoxy cast dry-type transformer have many advantages such as flame retardancy, self-extinguishing, moisture resistance, high mechanical strength, small size, light weight, and strong ability to withstand short circuits, and have been widely used. However, dry-type transformers also have some shortcomings. For example, in the case of poor ventilation, their heat dissipation performance is not as good as that of oil-immersed transformers. Based on our company’s many years of practical experience in using dry-type transformers, here are some insights on the operation and maintenance of dry-type transformers for reference.

1. Carry out regular cleaning work

If excessive dust accumulation is found, it must be removed immediately to ensure air circulation. In places with large dust accumulation, dry-type transformers should be cleaned at least once every six months. For dust in the ventilation ducts，Vacuum cleaner or compressed air should be used for removal. If not removed in time, it will affect the heat dissipation of the transformer, reduce the insulation of the transformer, and even cause insulation breakdown.

2. Actively carry out dehumidification and dehumidification work to ensure its dryness

In some relatively humid places (such as rainy, dark places), if a dry-type transformer that has been out of service is used, check whether there is abnormal moisture. If so, start hot air to dry the surface to prevent insulation breakdown. For  dry-type transformers, this surface moisture does not affect the insulation inside the windings, so it can be put into operation after treatment. Once the transformer is put into operation, the heat generated by its losses will return the insulation resistance to normal.

3. Actively carry out rust removal work to prevent iron core corrosion

The iron core of dry-type transformers is exposed to the air and is easily corroded. If large-area iron core corrosion occurs, the loss of the transformer will increase, the efficiency will decrease, and even directly affect the life of the transformer. Therefore, it is necessary to remove rust regularly to avoid iron core corrosion.