Transformers unloaded from the railway platform are transported either directly to the transformer workshop to prepare for installation, or are handed over to the warehouse for storage. Proper storage of transformers is of great importance both from the point of view of their installation, and especially, and from the point of view of the duration of their service life after installation during operation. The most vulnerable part of the transformer is the main isolation, t. e. insulation of windings from one another and from. Therefore, with prolonged storage of the transformer, all measures are taken to protect windings from the influence of the external environment. The volume and content of these measures are determined in which transformers are entered to the construction site from the plant. Transformers with a capacity of up to 1,800 kVA with a voltage of up to 35 kV inclusive are sent by a plant with an installed expand and filled with oil to a normal level. Immediately, after serving them to the warehouse, oil samples from the bottom of the tank is carried out to test its quality (determining the electrical strength and chemical analysis).
When storing these transformers, it is necessary to periodically check the oil level in the extensor and, when it decreases under the influence of changes in the environmental temperature, producing oil, periodically release moisture accumulated in it from the mud for the expander, as well as control the quality of oil according to the rules acting in this regard. For transformers with a capacity of more than 1,800 kv with a voltage of up to 35 kV inclusive, coming from the factory with a tank filled with oil, but with a diver removed during the transportation, no later than 10 days after arrival, the tightness of all the seals of the oil column with a height of 1.5 mV is checked. the course of 3 Cao, the oil sample is taken, as indicated above, the expand is installed and filled to the normal level of oil of proper quality.