Use Case: Transformer in substation

Adsorber (disposable) on Transfomer

Insulating oils for transformers are hygroscopic and strongly attract water molecules. If a transformer “breathes in” air from the environment, water molecules are also carried inside.  The insulating oil absorbs these. The use of a dehumidifier has therefore been standard in the field of transformers for years, because it dries the “inhaled” air in advance.

At GIEBEL, we have designed an adsorber especially for use on the transformer, whose maintenance requires only the opening of 3 quick-release fasteners and the replacement of the cartridge. The loaded cartridge can be returned to us for reconditioning (Send & Refresh).

Water content in insulating oil

The water content is responsible for the breakdown voltage of the insulating oil and the aging behavior of the liquid and solid insulation. The maximum water content in insulating oils is a low 40 ppm. If more water is present, it has a negative influence.

The breakdown voltage (index of the oil’s ability to withstand electrical stress) would increase. The introduction of moisture can also promote the formation of rust – especially in the expander – and thus cause high maintenance costs on the transformer.

Dehumidifiers protect the insulating oil

To achieve efficient air drying and long service intervals, it is necessary to install a dehumidifier at the transformer. GIEBEL adsorbers of the TB-DV series have a valve system (instead of an oil reservoir) and a layer of activated carbon to protect the silica gel from oil aerosols. They can be adapted to any transformer.

Note: In conventional dehumidifiers, oil is introduced into the silica gel through the oil reservoir, which negatively affects the effectiveness of the desiccant. Insufficient purification of the outflowing air and the additional load caused by the oil reservoir ensure that conventional dehumidifiers are contaminated on both sides and the drying of the air is limited. This then results in a continuous increase in humidity in the transformer. We counteract this with the special design of our adsorbers for transformers.