SCHEDULE 3 E+W+S CERTIFICATION TESTS AND TESTING METHODS FOR ALTERNATING CURRENT WATTHOUR METERS

Conditions for mixing methods of test E+W+S

(8) The method A test may be used for intermediate and high loads, at unity power factor and at 0.5 power factor, and the method B or method C test for the low load, provided that an additional method B or method C test is carried out at one of the test load values used for the method A test.