Power transformers are conduits of electricity that increase or decrease voltage efficiently. These machines are used for transferring power from one circuit to another without changing the frequency.

When electricity comes into the transformer from the power source, it is called primary voltage. Any voltage leaving the transformer is called secondary voltage. Two examples of transformers include step-down, which lowers voltage, and step-up, which raises voltage.

Step-down transformers have higher primary voltage than secondary. These transformers are useful for situations requiring a lesser voltage than provided by the power source. 

Step-up transformers have lower primary voltage than secondary. When the power source is inadequate, these transformers can provide a boost.

Technically, all transformers can operate in both step-down and step-up modes, so the attribution is given based on how the transformer is being used. 

Other types of transformers include: 

  • Three Phase: used in three phase power systems; most cost-effective
  • Distribution: steps down the voltage for commercial or domestic distribution; operates 24/7 with 50 percent of a full load at maximum efficiency
  • Electrical Power: operates at high or peak load times with maximum efficiency at or near full load; used in a transmission network to step up or down voltage
  •  Instrument: C.T. and P.T. are used to lower high voltage and current to levels that can be measured by common instruments
  • Autotransformer: used in situations where the ratio between the high voltage and low voltage is less than two
  • Two Winding Transformer: used in situations where the ratio between the high voltage and low voltage is greater than two
  • Outdoor/Indoor: specifically designed for either application
  • Oil Cooled: refers to the cooling medium as transformer oil
  • Dry Type: refers to the cooling medium as air cooling
  • Core Type: contains two vertical legs with two horizontal sections called yokes; rectangular with a common magnetic circuit
  • Shell Type: has a central limb and two outer limbs with a double-magnetic circuit
  • Berry Type: core resembles wheel spokes with tightly fitted metal sheet tanks; oil used inside

Are you looking for a specific type of transformer, or have one to sell? You’ve come to the right place! Contact the experts at J&P Electrical to talk about transformers today.


J&P Electrical is a full-service electrical supply company. At J&P, we source contractors, end-users, and supply houses with new surplus, quality reconditioned, and obsolete electrical equipment. We also purchase a wide range of heavy industrial electrical equipment such as bus plugs, bus duct, transformers, circuit breakers, fuses, and switchboards. Call us at 877-844-5514 or visit us at https://www.jpelectricalcompany.com.

Written by the digital marketing team at Creative Programs & Systems: www.cpsmi.com.

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