Silicone-resin-treated magnet coils

MAGNET COILS present somewhat different insulation problems from rotating machines. This was recognized when separate magnet coil standards^1–3 were set up by AIEE, National Electrical Manufacturers Association, and American Standards Association which permit higher maximum observable temperatures than do the rotating machine standards. AIEE Standard 1 states, “How long an insulation will last will depend not only on the class of material used but also upon the physical support of the insulation and the severity of the physical forces tending to disrupt it.” Following this line of reasoning, AIEE Standards 15 and 16 permit higher observable temperatures on magnet coils as shown in Table I. Work by Erikson⁴ indicates the desirability of separate consideration of magnet coils and suggests the possibility of higher operating temperatures even with organic insulation.