Resistors are components that are inserted in electrical circuits to modify the working conditions of equipment such as generators, motors or other receivers. Their operation is manifested in the form of heat energy, producing a rise in temperature, which will affect the components of the resistor itself and other equipment located in its vicinity.
The mass of the resistive material, the construction form and the location of the resistor are aspects to be carefully studied in the design and manufacture of a power resistor.
The maximum admissible temperature increase in the resistive material, the insulators and the air at the outlet of the resistor is regulated by different standards: NEMA, VDE, IEEE, etc. or the particular specifications of each project.