Get Ready for New Distribution Transformer Efficiency Rules

This audio was created using Microsoft Azure Speech Services

Customers relying on low-voltage distribution transformers need to be aware that new energy-efficiency standards mandated by the federal government go into effect on January 1, 2016.

The U.S. Department of Energy (DOE) requires that all distribution transformers, both low and medium voltage, comply by law with a new set of efficiency tables spelled out in 10 CFR 431, as of New Year’s Day.

DOE rules mandate that the efficiency of low-voltage, dry type distribution transformers “manufactured on or after January 1, 2016,” must meet minimum applicable kVA ratings as spelled out in the table below.


Manufacturers, including Schneider Electric, will publish transition plans for their products. Schneider Electric’s current plan is to have all larger orders release for production by the end of October and to continue to take orders for small quantities of 15 to 225kVA, 480 Delta Primary, 208Y/120 Secondary, Aluminum Windings, 150°C Rise with 220 Insulation till the end of the year.

The new product offering is available today for quotations and orders, but will not be available for shipment till the fourth quarter of 2015. These new units will be manufactured on new state of the art production lines being installed from third quarter 2015 through first quarter 2016.

In its ruling, the DOE argues the amended energy conservation standards for this equipment will “result in significant conservation of energy” and thus a reduction in CO2 emissions. For customers that purchase the new levels of efficiency low-voltage, dry-type distribution transformers, they should recover the premium in 10 – 12 years. Since the life of the transformer is the life of the building, the new levels of efficiency will drive reduction in energy and reduced total ownership costs to the building owners.

To help you better understand impacts, opportunities and solutions regarding these changes, please join us on July 21 @ 1:00 P.M. EDT for a one-hour continuing education webinar on energy codes, standards, applications and solutions surrounding Medium and Low Voltage Transformers and Efficient Solutions. Click here to register.


Tags: , , ,


  • Samir Sadek

    9 years ago

    This is a very good attempt for the dry type, but what for the oil cooled type??

    • Thomas Patzner

      9 years ago

      THe hour continuing education webinar on energy codes, standards, applications and solutions surrounding Medium and Low Voltage Transformers, will include the Oil Cooled units.

  • i have always doubted about the efficiency of low-voltage distribution transformers.

    • Thomas Patzner

      7 years ago

      Efficiency are calculated values using measure data. The two measure data follow NEMA ST-20 and 10 CFR 431.

      Transformer manufactures measure core loss @ 20°C – data used in calculation.
      Transformer manufactures measure coil loss @ 20°C – data is converted via formula to 20° above temperature rise (170°C on typical units). data is then converted to 75°C for DOE calculation.

      In 1992 the Industry determined to use for comparing two units 35% loading point, this is used by the DOE for the mandated levels.

      When determine the actual cost for transformers – the losses should be incorporated, and should be based on the loading profile over the 7/24/365 hours.

      Schneider Electric can help with these calulations, for a more acurate evaluation of the cost of Low Voltage Distribution Transformers.

Comments are closed.