Recent Entries

  • The maintenance on a tap changer of a Transformer

      The reason for the maintenance on a tap changer is to insure its reliability. Any device with moving parts, some of which are used to interrupt currents and voltages requires maintenance. It would be useless to repeat here what can be found in the manufacturers instruction books. We will onl...
  • Critical Loads and non Critical Loads

        Load management systems may prioritize loads based on the load type or importance. Load importance may vary widely depending on the application and facility, but often fall generally within one of the following categories: Non-Critical Loads These are loads that, if removed, will...
  • Short Circuit and Current Calculations with X/R and Utility Imp

        Download     What is X/R ("X over R") ratio, and why is it important? First, X/R ratio is simply the ratio of the system reactance to the system resistance, looking back to the power source from any point in a power circuit, assuming that a short circuit is applied t...
  • Limitation of transformer overloading

      Transformer Overloading and Limitations In the power systems, transformers could also be occasionally loaded above their name plate ratings during a response to emergency or contingency conditions. The overloading can also occur due to economic considerations. It is no got to install e...
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  • calculation of IDMT Earth Fault Relay Setting

      Download OVERVIEW OF RELAY COORDINATION Relay coordination has to be carried out based on many other power system studies and Equipment Sizing calculation, are listed below Load Flow Studies Short Circuit Studies Motor Starting Studies Transient Stability Studies Harmonic Anal...
  • Grounding neutral connection in substations

      Grounding transformer for neutral point connection is installed usually in vicinity of feeding transformers in substations. Consequently, overall configuration is protected with differential protection (Figure ). Depend of specific applications, current transformer is added with earthing r...
  • Selection of Fuses

      when talking about fuses two important factors. Fuses are rated by our current and voltage, the current determines at what current the fuse will blow and open the circuit never use a fuse of a different amp rating once the fuse has blown or open the circuit the voltage rating is very imp...
  • Underground cable routing

      Three possible approaches to the cable route design are generally available. Each of them shows a contrast between initial installation cost and the ease or cost with which any changes can be made to the existing cables, e.g., installing additional cables. These three options are: &nbs...
  • Power flow and power factor correction

      power system studies that can help you with design considerations and real savings on your power bill these studies include load flow power factor correction and harmonic analysisPower Systems load flow study is the first step in analyzing your system from the capacity standpoint to see ...
  • Fault current calculation in any point at a Substation

    This electrical calculator excel sheet will help you to find out the electrical fault at any point in a substation. There are two methods are introduced infinite method and MVA method calculations.   Download