Transformer applications and usage areas

Transformers are used in business, industry, and commerce as well as for schools and homes. They come in many sizes and shapes.

Six typical uses and applications of transformers are:

Distributing power at high voltages

Transformers are used for distributing power at 480 or 600 V and stepping down the voltage at the point of use (for 240-V motors, or 120-V equipment and lights). This results in better regulation of voltage and minimized line loss and reduces wiring costs.

Double-wiring elimination

Transformers are used to eliminate double wiring. For maximum safety, 120-V lighting and control circuits may be obtained from 240-, 480-, or 600-V power circuits by installing dry-type transformers at the most convenient location to the load. This eliminates separate circuits and independent metering for power and light and often results in large savings.

Operating 120/240-V equipment from power circuits

Transformers are used to operate portable tools, electrical control devices, alarms, relays, soldering irons, heating pots, small heat-treating furnaces, bench welders, and other high-current devices more economically from 120- or 240-V circuits supplied through a dry-type transformer from a high-voltage power circuit.

Isolating circuits

Transformers are used because of their ability to isolate one circuit from another. They can be air-cooled transformers and used as a means of subdividing circuits to accommodate independent demand. They can be connected to a three-phase, 480-V circuit, dry-type transformer to provide 120/240-V, three-wire, single-phase power for lighting loads. They can provide 120-V single-phase lighting loads or 240-V single-phase lighting or power loads. Transformers permit the grounding of each low-voltage circuit.

Changing from a four-wire to three-wire circuit

Transformers can be used to produce a three-wire, 120/240-V, single-phase circuit from the 120-V, two-wire circuit of a four-wire, 208Y/120-V, three-phase source. A three-phase primary of 240, 480, or 600 V may be used to provide a three-wire, 120/240-V, single-phase circuit.

Stepping-up or stepping-down voltage

Transformers can be used to step up or step down voltages simply by virtue of the turns ratio in the primary as compared to the secondary. Whenever the voltage source is lower or higher than the nominal required by the equipment load, a buck and boost transformer may be used.