Recent Entries

  • Key principles of operation when paralleling

      When generator sets operate in parallel, the engine speed governor of each generator set determines the proportional sharing of the total active power requirements (kW) of the system.  For two systems to be paralleled, each must have the following matching characteristics for correct...
  • Isolated neutral system

        When the system is totally isolated from the ground circuit, except through indicating, measuring or protective devices, which are normally grounded and possess a high impedance to ground, the ground fault factor     This may become higher, depending upon the circuit...
  • Proper sizing Variable Frequency drive (VFD)

        It’s tempting to pick a variable frequency drive supported horsepower alone. After all, if you select a drive that has the same or more horsepower than your motor you are using, then you should be good too – right? Well … not necessarily. There are six other b...
  • What is Residual Current Device (RCD)

          Residual-current device is protective and life-saving device. It is designed to protect from an electric shock, if you touch phase live conductor a current of 30 milli amperes can be lethal for a person, if it persists for more than a fraction of second. In most scenario in...
  • Transformer Fault current calculator

        Download   TRANSFORMER FAULT CURRENT Calculating the short Current when there is a Transformer within the circuit. Every transformer has “ %” impedance value stamped on the nameplate. Why is it stamped? it's stamped because it is a tested value after the transfo...
  • Introduction to Substation

      Electrical Engineering in order that subsequent time you feast your eyes on a substation you'll be ready to appreciate it the maximum amount as I do originally named for smaller power plants were converted for other purposes substation is now a general term for a facility which will serv...
  • Generator Protection

        power generators as we are well aware generators are built in an extremely wide range of sizes depending very much upon the application and the particular type of prime mover for example we may have a 500 kV a diesel driven generator which acts as standby for essential auxiliary se...
  • Principle and Selection of a Hydro-Electric Power Plant

     Hydro energy hydro energy is the energy generated by the force of water. This is a powerful way of generating electricity the hydro energy is converted into electric energy by hydro electric power plant and this energy is called as hydro electricity. History of hydro electric power plants wo...
  • Typical tripping curves by circuit breakers

      A coil, placed on each conductor, continuously measures the current in each of them This information is processed by an electronic module which controls the tripping of the circuit breaker when the values of the settings are exceeded The curve of the release shows three operating zones ...
  • Short circuit strength for medium voltage switchgear

        Short circuit strength for medium voltage switchgear   The following selection criteria are important for the short circuit strength of medium voltage switchgear : The rated short circuit breaking current Isc: this is the effective value of the breaking current at the ter...