Reducing Voltage Drop

Posted by Jacek Laszkiewicz on Jun 03, 2021

Consider a situation where a barn, cabin, or outbuilding is set far away from where the main electrical service terminates.  A long cable run at 120/240 must be made to the outbuilding. To minimize voltage drop, and the subsequent undesirable effects of low system voltage, electricians often rely on some common strategies:

  • Increasing cable size
  • Reducing cable length
  • Paralleling conductors

Using a pair of distribution transformers is a 4th option. Stepping up the voltage to 300/600 for the long cable run, and then down to 120/240 in the outbuilding can provide a technically and economically superior solution to simply oversizing cables.

  • By making the long run at 300/600, you can reduce the amperage in the cable and select a smaller wire gauge to save money in cabling.
  • By having a 600 to 120/240 transformer in the outbuilding, it allows an electrician to change the transformer taps to fine-tune the output voltage and mitigate even the smaller voltage losses across the 600v cable run.

Browse our catalog for transformers specifically designed for this application [link].


Conceptual one-line of a basic installation of two transformers in a step-up-step-down arrangement.
Conceptual one-line of a basic installation of two transformers in a step-up-step-down arrangement.

Wiring and connection details of a 240-300/600 transformer and a 600-120/240 transformer.
Wiring and connection details of a 240 to 300/600 transformer and a 600 to 120/240 transformer.

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