IEEE C57.12.23-2002

IEEE Standard for Underground Type, Self-Cooled, Single-Phase, Distribution Transformers with Separable Insulated High-Voltage Connectors; High Voltage 25000 V and Below; Low Voltage 600 V and Below; 167 kVA and Smaller
standard by IEEE, 08/08/2002

IEEE C62.43-2005

IEEE Guide for the Application of Surge Protectors Used in Low-Voltage (Equal to or Less than 1000 Vrms or 1200 Vdc) Data, Communications, and Signaling Circuits
standard by IEEE, 11/23/2005