Delete the second and third modification: Add, at the end of the fourth paragraph, after pollution degree 2 , the following text and overvoltage category III . Add, after the second paragraph, the following note: NOTE 1 Additional requirements are necessary for circuit-breakers used in locations having more severe overvoltage conditions. Replace in last but one modification paragraph 13 by paragraph 14 Delete the last modification: Renumber the existing note in paragraph 14 to NOTE 2 .