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Methods of Earthing In theory, the main power network does not have to be earthed and sometimes arguments are put forward that an unearthed network may be more reliable. In some cases this can be true, but generally an unearthed networks can be unreliable due to influence of electrical or some other factors. There are a number of ways in which an electrical power system can be operated – - Unearthed or insulated system - High impedance earthed and - Low impedance earthed arrangement Unearthed system/IT earthing system In this kind of installation, there is no formal connection to earth because there may be some high impedance connections for instrumentation e.g coil of a measuring device. Earthed vs Unearthed Electrical cable In some generators and transformers, the star point is solidly grounded. This is called Earthed Electrical system. In a three phase earthed system, phase to earth is 1.732(sqrt 3) is solidly earthed system higher than phase to phas

A fault is an unattractive or unsatisfactory feature, especially in a piece of work or in a person's character. An electrical fault, however, can be as a result of  -                                                           Open Circuit Fault                                                          Overload Fault                                                           Short Circuit Fault OPEN CIRCUIT FAULT -  An open circuit fault is a type of fault that occurs as a result of an opening in a circuit. It is a type of circuit in which there is no current flow which can occur as a result of wire breakage.  In the open circuit condition, we say that maximum resistance is present between two contacts. We can also have cases of the partial opening in the circuit, which might lead to contacts of a conducting surface not contacting/touching properly known as Partial contact .  The result is that there will be some voltage drop as a result of this partial contact which wil