Arc Flash in a Padmounted Switch

This app models the arc flash incident energy based on tests of PMH padmounted switches by EPRI and PG&E. For more information, see EPRI 1022697 [2011] and Short and Eblen [2012].

Notes

The incident energy in this equipment is higher than predicted by IEEE 1584 because of horizontal busbars. Magnetic fields from the arc current push the arcs and arc energy out of the enclosure towards the worker. This equipment is also unusual in that the incident energy is not linear with duration–the heat rate increases with increasing duration. Here is a picture of the horizontal busbars along with a video frame from an arc flash test:

References

EPRI 1022697, Distribution Arc Flash: Phase II Test Results and Analysis, Electric Power Research Institute, Palo Alto, CA, 2011.

Short, T. A. and Eblen, M. L., “Medium-Voltage Arc Flash in Open Air and Padmounted Equipment,” IEEE Transactions on Industry Applications, vol. 48, no. 1, pp. 245-253, Jan.-Feb. 2012. Approved version