Abstract
Electricity network expansion require the installation of new substations and switchgear
equipment. This, in many cases, is intended to cater for electrical energy demand much needed for
industrial operations. Such an increase in power available for use by consumers translates in high short
circuit capacity or fault level of the network, which in turn causes the arc flash incident energy to be
high in case of a fault. In this paper, the impact of network expansion on the arc flash incident energy
is assessed using the digsilent software version 15.1. The influence of protective relays time setting on
the reduction of arc flash energy, available during three-phase fault conditions, is also analysed for the
purpose of PPE specification. The results obtained show that an increase in the short circuit capacity or
fault level as well as in the fault clearing time, causes the arc flash incident energy to increase to higher
level than the corresponding PPE prescribed.