What is Voltage Rating?
Rated voltage refers to the optimal voltage for normal working of electrical equipment for a long time. The rated voltage is also called the nominal voltage. When the operating voltage of the electrical equipment is higher than the rated voltage, it is easy to damage the equipment, and it will not work normally when the voltage is lower than the rated voltage (such as the light bulb does not shine normally and the motor does not operate normally).
- At the rated voltage, electrical equipment, generators and transformers have the greatest economic benefits during normal operation. At this time, all parts of the equipment are working in the best state, the performance is relatively stable, and the life is relatively long. The rated voltage of the specified electrical equipment is conducive to the production standardization and serialization of the electrical appliance manufacturing industry, the standardization and selection of the design, the interconnection and replacement of electrical appliances, and the production and maintenance of spare parts. Also, to avoid
- The grid voltage is graded, and the rated voltages of power equipment in the grids at different levels are quite different. Electricity
- Rated voltage in each level of power grid
- Rated voltage of electrical equipment
- Rated voltage of electrical equipment = rated power x resistance
- The calculation method of the rated voltage of the appliance is the same as the calculation method of the ordinary voltage, but it is usually a fixed value in order to match the power supply system. The rated voltage of the electrical equipment is the same as the rated voltage of the power grid. In fact, due to voltage loss in the power grid, the actual voltage at each point deviates from the rated value. In order to ensure the good operation of power equipment, the state has strict regulations on voltage deviations at various levels of the power grid. Obviously, the electrical equipment should have a wider normal operating voltage range than the allowable deviation of the grid voltage.
- Lamp rated voltage label
- The current rated voltage of electrical appliances in China is 220V (single-line electrical appliances, such as daily household appliances) or 380V (three-line electrical appliances, such as high-power motors). The rated voltage and rated power of the electrical equipment are marked on the label, such as the bulb "PZ220-40" and the hair dryer "220V 1000W", where 220 represents the rated voltage.
- Rated voltage of the power supply system
- The rated voltage of the power grid is equal to the average of the voltages at the ends of the line. This voltage is used as the basis for determining the rated voltage of other electrical equipment.
- The rated voltage of the generator is specified to be 5% higher than the grid voltage of the same level.
- The rated voltage of the power transformer transformer is divided into primary and secondary windings. For the primary winding, when the transformer is connected to the end of the grid, it is equivalent in nature to a load on the grid (such as a factory step-down transformer), so its rated voltage is consistent with the grid; when the transformer is connected to the generator's outlet (such as a power plant Step-up transformer), the rated voltage should be the same as the rated voltage of the generator. For the secondary winding, the rated voltage refers to the no-load voltage. Taking into account the voltage loss of the transformer when it is carried (in terms of 5%), the rated voltage of the secondary winding of the transformer should be 5% higher than the rated voltage of the power grid. In the long term, the line voltage loss (in terms of 5%) should also be considered. At this time, the rated voltage of the secondary winding should be 10% higher than the rated voltage of the power grid. [2]