This report describes how the Japanese Electric Wire and Cable Maker's Association established the most appropriate current for power cables with economy and environment in mind as one of their standards. The current is intended for low-voltage CVT cables used commonly in factories and buildings. The report provides estimated reductions in distribution losses and CO2 emissions when all low-voltage CVT cables in sites of consumers in Japan are switched to those with upsized conductors, revealing the total annual reduction in distribution losses in Japan.