Results of Arc Processes Registration in Single-Phase Short Circuits of Low-Voltage Power Grids with an Isolated Neutral

Electrical networks with isolated neutral at low voltage (IT systems) have become very widespread. Their main property is the possibility of long-term operation in the single-phase circuit mode. However, in many cases, single-phase insulation damage is accompanied by arc processes that make the short circuits of the type especially dangerous. The characteristics of the grounding arc determine if a single-phase short circuit can transition to a short circuit and if vapor- and gas-air mixtures in the environment of an arc circuit occur can ignite or explode. The paper presents the results of studies into the arc processes when the single-phase damage to rubber-insulated cables occurs. It provides an experimental evaluation of the arc discharges parameters, including the heat release rate at the short circuit point, maximum arc current surges and arc resistance.