Arc Flash Pressure Rise & Temperature Rise Calculations

PCE were engaged by a large electrical equipment supplier to conduct arc flash calculations on a range of local control stations, housing visual break isolators. The client required theoretical arc flash modelling for its range of equipment to meet the requirements of IEC 61439 (Type Tested Assemblies) and IEC/TR 61641:2014 (Arc Fault Containment).

The calculation methodology encompassed the pressure rise inside the enclosure during an arcing fault, with arcing fault current magnitudes calculated as per IEEE 1584:2018. Analysis was undertaken for the entire range of enclosures, varying in size, loading and build.

The local control station range was further reviewed with respect to maximum temperature rise during full load. Using temperature distribution analysis software, maximum internal temperature and heat exchange power was calculated for each LCS. Temperature calculations were repeated for all feasible installation methods of the enclosure.