Electrical safety in street lighting systems against loss of service continuity and shock hazards

For the street light systems, the worldwide trend of electrical standards encourages the adoption of class II equipment such as light fixtures, cabling systems, and other components with double insulation. In installations of a largest number of light poles, safety degradation could be possible and so dangerous electrical potentials may appear on the steel poles that expose people to shock hazards. To decrease the risk to an enhanced low level, also against natural and anthropic events, different solutions are available. In this paper, the authors deal with a combined action of two safety measures for existing installations with steel poles not interconnected by a common grounding system. In particular, these measures are the insulation of the steel poles by an adequate varnish against shock hazards in faulted conditions and the protection of supplying circuits by residual current devices. These RCDs avoid the permanence of ground faults and provide their auto-reclosing with a circuit insulation control.