These are devices that increase or decrease a specific voltage value. The transformer consists of a core and two coils. The core is made of a ferromagnetic material, and the coils are composed of a different number of turns, called primary and secondary. The primary coil receives the voltage from the mains, and the secondary coil receives the transformed voltage.

• Transformer: The transformer consists of two windings isolated from each other, which will surround the same core; this physical separation between the windings guarantees an advantage to the transformer: This isolation between the network and the load ensures protection for both against possible disturbances that may be created from the network to the load or even from the load to the network. The transformer will have larger dimensions and there will be a considerable increase in price due to the greater amount of material used in its manufacture.
• Autotransformer: Unlike the transformer, it consists of only one winding, and according to the desired transformation, a "tap" will be derived from a certain part of the winding, and at this point we will have different values than those found at the input of the autotransformer. The differentiated configuration guarantees certain advantages: Better efficiency is found in the autotransformer, and there will be less voltage drop in these models. In addition, this model guarantees a reduced price compared to the transformer, as it uses less material in its construction.

Single-phase transformer: It consists of two windings that form a set of coils, one primary coil, which receives the higher voltage, and a secondary coil that provides the lower voltage. Both are installed on the same ferromagnetic core. Three-phase transformer: It consists of three windings in the primary and three in the secondary, forming a set of three coils, installed on a core. The coils of this transformer can be connected in Y (star) or (delta).

It is measured in Volts, and its symbol is the capital letter "V". In Brazil, the voltages normally used are: Single-phase: 110V, 127V, 220V | Three-phase: 220V, 380V.

Measured in Amperes, its symbol is the capital letter "A", current ultimately determines the "amount" of energy used to power a given piece of electrical equipment or device.

It is measured in Volt-Ampere, and its symbol is the capital letter "VA". When the power in VA is not defined, it can be calculated as follows: Single-phase: Voltage x Current (V x A) = Power (VA) Example: 220V x 15A = 3300 VA or 3.3kVA Three-phase: Voltage x Current x constant (V x A x ) = Power in VA Example: 380V x 15A x = 9872 VA or 9.87kVA

PRIMARY or INPUT: Identifies the voltages that will power the transformer. It can be just one voltage, for example 220V, or more than one, for example 220-380-440V. When the transformer is designed for more than one input, it becomes more flexible and can be used in any of the conditions. SECONDARY or OUTPUT: Identifies the voltages that will be modified by the transformer. In this case, there may also be one or more outputs, depending on the specific needs of each customer. Example: 0-24-110-220V (taps); 0-24V / 0-110V / 220V (independent windings)

These autotransformer models are used in motor starting that utilize a compensator starter. The center points are called TAPs, typically at 65% and 80% of the voltage. The number of starts per hour is specified, which can be 5s or 10s at equal intervals.

Reactors (or inductors) are used as harmonic filters in capacitor banks, converters, rectifiers, frequency inverters, and other equipment. They can be installed at the input or output of the powered equipment, depending on the design.

Transformer model (autotransformer or isolation transformer; single-phase or three-phase) Power (VA or kVA), voltage (V) to current (A) ratio. Voltage ratio (Input(s) and Output(s)) (V) Dimensions (only if necessary due to space limitations) Connection type (for single-phase: Connector, terminal block or cable)

These are measures applied to the enclosure of electrical equipment, aiming to: a) Protect people from contact with uninsulated live parts; from contact with moving parts inside the enclosure; and protect against the entry of foreign solid objects. b) Protect the equipment from water ingress. Enclosures (or protective boxes) are designated by a symbol consisting of the abbreviation "IP" followed by two digits, which classify the degree of protection of the electrical equipment. Enclosure specifications follow the international standards NBR 6146 and NBR 9884.