In Japan, the technical standards for electrical installations (電氣設備技術基準解釋) has adopted IEC 60364 and IEC 61936-1 as alternative to the Japanese standards. So we can choose either one for designs but it would be difficult to apply IEC standards because Japanese end users are not familiar with IEC (and English). JIS introduces IEC as alternatives as well (but not replaced). JEC and JEM remain the Japanese way but always compare with IEC for technical aspects when revisions and sometimes add explanations for particular differences between them.

How do Korean end users/engineers/authorities prepare for the change ? Chaos does come if the same is implemented in Japan.

Best regards,

Ishiki