JP · Top Runner transformer criteria; JIS C 4304 and JIS C 4306 measurement references
Distribution transformers: FY2026 Top Runner criteria
Identify the market and product category first. Each dossier separates legal duties, referenced standards, evidence and the comparison needed for an award.
Product Scope
Transformers within the specified voltage/capacity and construction scope, separated by oil-filled/moulded type, phase, frequency and specification.
Requirements
Energy consumption efficiency is total loss from no-load and load losses under the cited methods. Choose the applicable category formula and target fiscal year; the official page separately provides FY2026 criteria.
Required Evidence
Provide rated data, construction/category assignment, no-load and load-loss tests, calculation and applicable shipment-weighted evidence.
Comparison for the Awards
Compare the same capacity and category under the same method. Lower losses are beneficial; a different transformer rating cannot be used as an easier baseline.
Version & Transition
FY2026 and subsequent-year formulas differ from earlier target-year tables. Keep the selected table and fiscal year attached to the comparison.
Official Sources
Applicability depends on the product classification, intended use, configuration and actual sales territory. Manufacturing, placing-on-the-market and testing dates, together with transition provisions, are checked as required by each applicable rule. The directory identifies sources; it does not replace assessment of the specific model. Standards are identified by reference, and their authoritative texts remain with the issuing bodies. Official source documents retain their original language.