underground fault location model using arduino. Underground distribution cables faces with various technical difficulties regarding detecting and locating their faults. Different factors like remarkable charging currents, cable construction and variations from the variety of bonding and grounding methodologies. Arduino is basically an open source hardware used to create interactive electronic objects consisting of various analog and digital pins, serial communication interfaces, including USB on some models, for loading programs (c++, c, and java) from personal computers. The LCD (liquid crystal display) used is of 16*2 displays. In this paper, concept of ohm’s law is used. To detect a fault in the cable, the cable must first be tested for faults. When any fault like short-circuit occurs, voltage drop will vary depending on the length of fault in cable, since the current varies. A set of resistors are therefore used representing cable length in kilo meters and fault creation is made by a set of switches at every known kilo meters (km’s) to cross-check the accuracy . The fault occurring at what distance and which phase is displayed on a lcd interfaced with the arduino. The underground cable system is especially used for distribution in metropolitan cities, airports and defense service, because underground cables are not affected by any adverse weather conditions.