Discussion of "Flammable vapor ignition initiated by hot rotor surfaces within an induction motor: reality or not?"

The author argues that the original paper's authors (Hamer et al., see ibid., vol. 34, no. 1, p. 100-11, 1999) have made a positive contribution to the knowledge of operating electrical equipment in hazardous atmospheres by demonstrating that the published autoignition temperatures (AITs) for the tested gases are very conservative. He believes that further testing possibly should be performed to better define these AITs; however, the results of these tests indicate to him that there is no reason to consider changing any practices concerning the use of three-phase squirrel-cage motors in Class I, Division 2 locations.