Arc Flash
Estimate incident energy and PPE category for arc flash.
Questions
Each answer describes what this tool calculates. The result is a design aid. Verify against the current standard.
What does the arc flash calculator do?
The tool estimates the arcing current, the incident energy at the working distance and the arc flash boundary. It then reports a PPE category for that energy. The steps show the electrode gap, the calculation factor and the distance exponent that were used.
Which model does it use?
It uses the empirical model of IEEE 1584-2002. The 2018 model is not available in the tool yet. Above 15 kV the empirical model does not apply, so the tool switches to the Lee model and says so in a note.
Which inputs matter most?
The bolted fault current and the clearing time drive the incident energy. The working distance also matters and defaults to 455 mm. The equipment type sets the electrode gap and the distance exponent. The enclosed and grounded settings change the energy constants.
How is the PPE category decided?
The tool sets the category from the incident energy in calories per square centimetre. The band edges it uses are 1.2, 4, 8, 25 and 40. Above 40 the result is reported as above category 4. Inputs sit in the page address, so a link reproduces the study case.