User:Fluppe37/sandbox

Chalcocite formation in power transformers
In power transformers where sulfur antioxidants are present in the transformer oil and under a number of conditions, Chalcocite is formed on the copper conductor or deposited in the electrical insulation paper. The presence of conductive salts in high elektrical stress regions causes Electric arc and failure of the equipment. The risc conditions are:
 * Transformer filled with corrosive oil
 * High service temperature; above 150°C
 * No dissolved oxygen in the oil due to a hermetically sealed transformer or with rubber bag in the conservator
 * Application of unvarnished copper wire