Subject to the selected calculation method, different equipment data is required for an arc flash hazard analysis. We recommend using the IEEE 1584 empirically derived model for arc flash study due to the method's ability to accurately account for a wide variety of setup parameters:
For cases where voltage is over 15kV or gap is outside the range of the model, the theoretically derived Lee method can be applied and is included in the ARCAD Arc Flash Analytic software and mobile apps. The method requires the following equipment data for an arc-flash hazard study:
|System voltage, V|
|Available 3-phase short circuit current (ASCC), kA|
|Part of ASCC through upstream protection device, kA|
|Type of enclosure (Open Air | Switchgear | MCC & Panel | Cable)|
|Upstream protection device|
|Gap between exposed conductors, mm.|
|Grounding type (grounded | ungrounded)|
|Working distance, mm.|
|Incident energy @ AFB, cal/cm2|
The incident energy at arc flash boundary (AFB) of 1.2 cal/cm^2 for bare skin is used in solving equation for arc flash boundary in the IEEE 1584 Guide for Performing Arc Flash Hazard Calculations. However, the Guide equation for arc flash boundary can be solved with other incident energy levels as well such as the rating of proposed personal protective equipment (PPE). It is shown that the incident energy at AFB is rather a variable function of heat flux, and the arc flash boundary equation should be in fact solved for boundary energy computed using the Equation 2 especially for cased when arc duration is less than one (1) second. ARCAD's AFA V5.0 software is the first and currently the only arc flash software capable to calculate arc flash boundaries based on the 1.2 cal/cm2 (5 Joules/cm2) incident energy or the evaluated onset to second degree burn energy.
© 2017 ARCAD INC. All rights reserved.