Try Our Substation Physical Electrical Clearance & Correction Factor Calculator Tool


This is a basic substation physical conductor spacing tool that provides the minimum conductor clearances for phase-to-phase, phase-to-ground, and clearances above grade for the following voltage levels according to NEMA / IEEE standards and substation design best practices. This tool also provides the basic insulation level (BIL) for each voltage level input and correction factors for voltage, current and temperature to aid the substation designer / engineer. This tool is only used for outdoor air insulated substations (AIS) and does not apply for gas insulated substations (GIS). Please review the NEMA and IEEE standards as well as power engineering substation design recommendations for more details.