DFA Training Material
The DFA technology system detects and reports multiple types of events that occur along the length of a distribution circuit.1 One type of event is series arcing. Series arcing often results in low-amplitude variations in line current and voltage and represents an incipient failure, or “hot spot,” that is developing in the jaws of a load-carrying line device, such as a switch or a clamp. The condition can exist for hours, days, or weeks without customer complaints or other notice to the utility. It causes progressive erosion of line conductors and of the affected device’s contacts and ultimately can result in intermittent voltage fluctuations, flickering lights, unexplained protection operations, and even broken conductors.
There can often be some confusion over how the information gained from DFA can be used to identify the location for differing types of fault events. Similarly, there can also be confusion as to when and where it is possible to utilise DFA information to model likely fault locations within a proprietary system modelling package or within Aspen’s Fault Locator tool.
This paper outlines the differences between the types of system events and faults encountered by the DFA and provides guidance over how to use the information to locate the faults as quickly and efficiently as possible.