Comments on 'Compatibility-the neglected factor in insulation evaluation' by W.B. Penn (DC machine insulation)

For original paper see ibid., vol.4, no.2, p.27 (1988). The commenter addresses statements by the author of the above paper concerning silicone and rapid brushwear in DC machines. This problem, which was noted several years ago, is due to improper curing of silicone products. He maintains that when proper curing is completed, silicone varnishes are the best materials to use in totally enclosed DC machines due to their lack of degradation at operating temperatures.<
>