2009IEEE C57.12.23-2009 Submersible Single-Phase Transformers: 167 kVA and Smaller; High Voltage 25 000 V and Below; Low Voltage 600 V and Below
2002IEEE C57.12.23-2002 Standard for Underground Type@ Self-Cooled@Single-Phase@ Distribution Transformers with Separable Insulated High-Voltage Connectors; High Voltage 25 000 V and Below; Low Voltage 600 V and Below; 167 kVA and Smaller
1992IEEE C57.12.23-1992 Standard for Transformers - Underground-Type@ Self-Cooled@ Single- Phase Distribution Transformers with Separable@ Insulated@ High-Voltage Connectors; High Voltage (24 940 GrdY/14 400 V and Below) and Low Voltage (240/120 V@ 167 kVA and Smaller)