The purpose of this trial-use guide is to present general background information and recommendations for the operation of power apparatus bushings at currents greater than nameplate rating. This trial-use guide covers bushings manufactured in accordance with ANSI/IEEE Std 21-1976 [2]1 and ANSI/IEEE Std 24-1984 [3] applied to power transformers 501 kVA through 100 000 kVA when loaded in accordance with ANSI/IEEE C57.92-1981 [1].