JEC 210 and JEC 212 are the Japanese standards that define surge test methods for low voltage circuits, issued by the Japanese Institute of Electrical Engineers, and they matter to any supplier whose product is qualified by a Japanese customer because the test practice they establish differs in some respects from the European and international one. The Japanese practice has long been built around a combination of the 1.2 by 50 microsecond voltage waveform and the 8 by 20 microsecond current waveform applied through a specified source impedance, and around an arrangement of coupling in which both the line to line and the line to earth paths are exercised at defined phase angles. A characteristic of the Japanese approach is that the test is frequently performed at a level higher than the international equivalent, with a common practice being to apply the surge at seven kilovolts from a low impedance source, which places a greater demand on the protective components in the product.