5.2.2 Test procedure Unless otherwi

5.2.2 Test procedure Unless otherwise specified elsewhere in this standard the insulation is subjected either to a voltage of substantially sine-wave form having a frequency of 50 Hz or 60 Hz, or to a d.c. test voltage equal to the peak voltage of the prescribed a.c. test voltage. The test voltages for electric strength for the appropriate grade of insulation [FUNCTIONAL INSULATION if required by 5.3.4 b), BASIC INSULATION, SUPPLEMENTARY INSULATION or REINFORCED INSULATION] are as specified in either: − Table 5B using the PEAK WORKING VOLTAGE (U), as determined in 2.10.2; or− Table 5C using the REQUIRED WITHSTAND VOLTAGE, as determined in G.4.NOTE 1 In various places in this standard, special electric strength tests or test voltages are specified for certain situations. The test voltages in 5.2.2 do not apply to these situations. NOTE 2 For consideration of temporary overvoltages, see IEC 60664-1. For equipment in Overvoltage Category I and Overvoltage Category II, it is permitted to use either Table 5B or Table 5C. However, for a SECONDARY CIRCUIT that is neither connected to protective earth nor provided with a protective screen in accordance with 2.6.1 e), Table 5C shall be used. For equipment in Overvoltage Category III and Overvoltage Category IV, Table 5C shall be used. The voltage applied to the insulation under test is gradually raised from zero to the prescribed voltage and held at that value for 60 s.