Impulse voltage withstand capability of rotating machine insulation as determined from model specimens

An evaluation of present-day turn and groundwall insulation is discussed. The surge breakdown voltage of unaged insulated specimens was evaluated at two rates of surge voltage rise; the values of breakdown voltage were compared to those obtained by direct voltage and 60 Hz alternating voltage. The insulations were then aged by voltage from conductor to ground and periodically evaluated for surge breakdown values. Finally, the specimens were tested for surge voltage endurance, and this endurance was compared to alternating voltage endurance.<
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