IEEE Std C57.12.24-2000
變壓器美國國家標準 埋地式三相配電變壓器2500kVA及以下；高壓：34,500 GrdY/29 920 伏及以下；低壓：480 伏及以下 要求
American National Standard for Transformers-- Underground-Type Three-Phase Distribution Transformers 2500 kVA and Smaller; High Voltage: 34,500 GrdY/29 920 Volts and Below; Low Voltage: 480 Volts and Below--Requirements