Fire hazards and welding action in service-entrance conductors

Service-entrance conductors between the customer´s service-entrance equipment and the power company pole transformer are not covered by the National Electric Code (NEC) and often have entirely inadequate overcurrent protection. Power companies fuse to protect their transformer and not the individual service materials which may supply a number of customers. Thus currents in excess of a 1000 A can flow for a considerable time as a result of short circuits in the service-entrance conductors. Often these conductors are enclosed in a steel conduit between where they enter the building and meter box, and/or service equipment, and the welding action of shorts in this conduit melts the steel of the conduit and starts fires long before the pole-transformer fuse blows. Several such fires are documented in this report. Possible solutions to this hazard are proposed.