Ojha Gaurav et al; International Journal of Advance Research, Ideas and Innovations in Technology. © 2017, www.IJARIIT.com All Rights Reserved Page | 550 ISSN: 2454-132X Impact factor: 4.295 (Volume3, Issue2) Underground Cable Fault Distance Locator Gaurav Ojha Department of Electrical and Electronics Engineering PSIT, Kanpur India ojhagaurav@gmail.com Abhilash Guha Roy Department of Electrical and Electronics Engineering PSIT, Kanpur India abhiiguharoy@gmail.com Rahul Verma Department of Electrical and Electronics Engineering PSIT, Kanpur India rahulverma02july@gmail.com Vishal Kumar Department of Electrical and Electronics Engineering PSIT, Kanpur India kumarvishal8840@gmail.com Abstract: In this paper, a method to detect the fault and the distance at which the fault has occurred is calculated. The fault location in the underground cable is a bit cumbersome process so to deal with such problem a method is given in this project. To determine the location of fault a series resistor is used and the voltage across this resistor is measured and then is sent to the microprocessor to calculate the distance at which the fault has occurred. This is a safe and cheap method for obtaining the fault location in an underground cable. This method also does not have a high power requirement and is portable too. Keywords: Underground Cable, Fault Detection, Fault Location, Microprocessor. I. INTRODUCTION Most of the transmission lines are laid using overhead line method but transmission line by underground method also finds its use and application over a large area. In areas like hospitals or colleges, underground cable is widely preferred to ensure safety. Underground cable installations are costly as compared to overhead cable but are more reliable and also the life of underground cable are more as compared to overhead lines. Although underground cables are unaffected by adverse conditions like a storm, rainfall and the chances for fault in underground cables are less than that of overhead cables but when the fault happens at undergrounds cables its detection becomes difficult. So it becomes essential to calculate the distance of fault for an efficient way to employ underground cable method. TYPES OF FAULT Fault in a cable can be classified as: A.) Open circuit fault B.) Short circuit fault Open circuit fault This type of fault is caused by breaking in conducting path etc. Such fault happens when one or more phase conductor wire break. The value of current in such fault becomes zero and the load side gets isolated from the Generation side. This fault is less harmful as no current flows when short circuit fault occurs. Short circuit fault When conductors of different phases get connected with each other than such fault comes under short circuit fault. In this type of fault the value of current increases so it becomes harmful at the load ends. There are basically 2 types of short circuit fault:- i. Symmetrical Fault ii. Unsymmetrical Fault Symmetrical Fault: the 3-phase fault is called a symmetrical fault. In this, all 3-phases are short-circuited. In this fault the phase angles are unchanged but the magnitude of the current can vary. Unsymmetrical Fault: In this fault magnitude of the current is not equal and also not displaced by 120-degree angle. The different phases are short-circuited with each other.