Formula variables
- Line-neutral voltage is measured from one phase conductor to neutral.
- Line-line voltage is measured between two phase conductors.
- sqrt(3) is the balanced three-phase voltage ratio.
- The result is a nominal planning value, not a field measurement.
Assumptions
- The calculation assumes a balanced three-phase system.
- Line-line voltage equals line-neutral voltage multiplied by sqrt(3).
- Line-neutral voltage equals line-line voltage divided by sqrt(3).
- Utility service, transformer taps, measured voltage, and equipment nameplates can differ from nominal values.
Examples
347 V lighting system. A 347 V line-neutral system converts to about 601 V line-line, commonly treated as a 600 V class system.
600 V service. A 600 V line-line system converts to about 346.4 V line-neutral for balanced three-phase planning.