IEEE/ANSI C57.12.22-1995
帶高壓套管、2500 kVA 及更小的墊裝式、隔間式、自冷卻三相配電變壓器的美國國家標準；高壓，34 500 GrdY/19 920 伏及以下；低壓，480 伏及以下
American National Standard for Pad-Mounted, Compartmental-Type, Self-Cooled, Three-Phase Distribution Transformers With High-Voltage Bushings, 2500 kVA and Smaller; High Voltage, 34 500 GrdY/19 920 Volts and Below; Low Voltage, 480 Volts and Below