2.5 Electric strength
2.5.1 This test shall not apply to lamps having caps with internal resistors.
2.5.2 The insulation between the shell of the cap and the pin(s) or contacts shall withstand the test voltage. No flash-over or breakdown shall occur during the test.
2.5.3 Compliance is checked with a 1 500 V a.c. voltage of substantially sine-wave form, with a frequency of 50 Hz or 60 Hz and applied for 1 min. Initially, not more than half the prescribed voltage shall be applied; it shall then be raised rapidly to the full value.
Glow discharges without a drop in voltage are neglected.