Target Scope

Transformers that run on alternating current and whose rated primary voltage is over 600V up to 7,000V, except the following:

1) ones using gas for insulation,

2) ones using H type insulation material,

3) ones with Scott connection,

4) ones having 3 or more windings,

5) ones installed on utility poles,

6) single-phase transformers whose rated capacity is up to 5 kVA or over 500 kVA,

7) triple-phase transformers whose rated capacity is up to 10 KVA or over 2,000 KVA,

8) triple-phase transformers using resinous insulation material and intended to transform triple-phase AC to single-phase AC and triple-phase AC,

9) ones whose rated secondary voltage is less than 100 V or over 600 V, or

10) ones of air-cooling type or water-cooling type.


Energy Consumption Efficiency

Energy consumption efficiency shall be the total loss (W) acquired through the no-load loss (W) and load loss (W) measured using the method stipulated by JIS C 4304 and C 4306.


Categories & Target Standard Values

In the target fiscal year and each subsequent fiscal year, for each category, the weighted average value obtained by weighting energy consumption efficiency with shipment volume shall not be above the target standard value which is a weighted average value obtained by weighting standard energy consumption efficiency*1 with shipment volume.

*1: Values obtained from the standard energy consumption efficiency calculation formulas.

Category Standard energy consumption calculation formula
Transformer type Number of phases Rated frequency Rated capacity
Oil-filled transformer Single phase 50Hz E=11.2S0.732
60Hz E=11.1S0.725
Triple phase 50Hz Up to 500 kVA E=16.6S0.696
Over 500 kVA E=11.1S0.809
60Hz Up to 500 kVA E=17.3S0.678
Over 500 kVA E=11.7S0.790
Molded transformer Single phase 50Hz E=16.9S0.674
60Hz E=15.2S0.691
Triple phase 50Hz Up to 500 kVA E=23.9S0.659
Over 500 kVA E=22.7S0.718
60Hz Up to 500 kVA E=22.3S0.674
Over 500 kVA E=19.4S0.737
* For transformers that are not used under standard specification conditions stipulated in JIS C 4304 and JIS C 4306, the right side of the formulas shall be multiplied by 1.10 for oil-filled transformers and 1.05 for molded transformers respectively.
  1. “Oil-filled transformers” are transformers that use insulating oil as insulating materials.
  2. “Molded transformers” are transformers that use resin insulating materials.
  3. E and S express the following numeric values.
    E: Standard energy consumption efficiency (unit: Watt)
    S: Rated capacity (unit: kVA)


Target Fiscal Year

FY2014 and each subsequent fiscal year


Energy Efficiency Improvement

Energy consumption efficiency is expected to be improved by about 12.5% compared with the FY2009 in the target year (FY2014).


Display Items

●Product name and type

●Transformer type

●Rated capacity

●Number of phases

●Rated frequency

●Rated primary and secondary voltage

●Energy consumption efficiency

●Standard load factor

●Name of standard

●Name of manufacturer, etc.


Display Location

Display items shall be presented at locations where they can be readily noticed in catalogs showing performance indications and in documents provided by the manufacturer for product selection.


Requirement for Recommendations and Orders

Manufacturers or importers whose annual manufacturing volume or importing volume (limited to shipment to the domestic market) is 100 units or more may be subject to recommendations and orders.