Arquivos mensais: agosto 2017

Continuous and Alternating Current

Electric motors consist of machines capable of transforming electrical-type energy into mechanical energy. The electric motor considered the most used in the industries is the induction, since it has been able to combine the numerous advantages of the use of electric energy, low cost, easy transportation and handling, effective performance, simplicity of command with simple and large projection Versatility of adaptations to the most different types of loads. The types of electric motors found considered to be the most common are electric motors of direct current and alternating current.

AC motors are the most used, taking into account that the distribution of electric energy is effected in alternating current. The main types of the same are the synchronous and induction motors. While DC motors are more expensive and need a direct current source, or a device that converts ordinary AC power to DC. They can operate at an adjustable speed with wide limits and flexible and precise controls. In this way, its use becomes restricted only to specific cases in which these requirements can compensate the high cost of the installation.


Tank with Oil Conservative

One of the first alternative methods of preserving oil was the tank with a preservative. In conservative transformers, the main reservoir is completely filled with oil, and a smaller reservoir with a small amount of oil, the conservative tank, is mounted above the main tank and connected by a tube called a gooseneck.

The conservator is ventilated by air, and during its normal operation, its oil level will be halved to allow expansion and contraction of the oil at the time of a critical operation.

The goal of the gooseneck is to prevent the contact of hot oil, generated by the core and the transformer coils with the conserved oil cooled. This result is partial, since there is always some contact between the two oils.

skf mrosupply 2017

The oil in the main tank of the transformer is under a slight positive pressure, equal to that of the conservator. In the conservator, a dehumidifier can be installed to keep the oil free of moisture, which works for time-fitted transformers.

The dehumidifier has to be replaced at regular intervals and the change from pink to blue will indicate when replacement needs to be made.