The ballast shall not impair safety when operated under abnormal conditions at any voltage between 90 % and 110 % of the rated supply voltage.
Duration: 1h
15.1 verified with dummy cathode resistors inserted and conditions of abnormal operation
15.2 conditions of abnormal operation, measured from 5 s after the switch on or beginning of the starting process
15.3 For a period longer than 30 s after switch-on, or beginning of the starting process. For ballasts which make more than one attempt to start a failed lamp, the combined duration of voltages above the maximum working voltage for which the ballast is declared shall not exceed 30 s.
c) the lamp does not start although the cathode circuits are intact (de-activated lamp);