Recent Entries

  • Electrical cables in the substation

    As regards the cables, in substations we can have the following situations: – accessible sub-panel compartment, or a walkable basement under the supporting plane of the switchgear, for which a net height of not less than 1.7 m is recommended. This solution is suitable for cases where the ca...
  • Functions of the substation with MV metering

        Connection to the MV network can be made: b By a single service cable or overhead line, b By dual parallel feeders via two mechanically interlocked load-break switches b Via a ring main unit including two load-break switches.   MV/LV Transformers and internal MV distrib...
  • Electrical Load calculation excel sheet

      Using this excel sheet will help us to calculate electrical load . Download
  • Different connections of windings in transformers

    In general, building distribution transformers are star- connected on the low voltage side to eliminate circulating triplen harmonics (3rd, 9th, 15th etc.) in a delta-connected three-phase winding. The high voltage side is almost always delta connected.   There are many possible variations ...
  • Relays and circuit breakers

    Faults in electrical systems are of two main types; symmetrical (with three-phases) and unsymmetrical (with one or two phases) faults. Lightning, which is a form of excessive charge, is the number one cause of electrical faults, as it interrupts normal current flow at high level transmission, and ...
  • Electrical energy through the arc-flash

        Industry is now addressing the impact to the worker of other energies transformed from electrical energy through the arc-flash event (see Figure ). These energies include electrical, thermal, acoustic, radiation, chemical, and mechanical that may cause excessive noise intense h...
  • What is Power Capacitors?

    POWER CAPACITORS. Power capacitors are used in distribution systems to supply reactive volt-amperes (Vars) to the system. When applied to a system or circuit having a lagging power factor, several beneficial results are obtained. These results include power factor increase, voltage increase, sys...
  • Excel sheet to size Transformer, Breaker and fuse

    Using this excesheet you will be able to calculate the transformer size and breaker size and fuse size.   Download
  • Undervoltage Protection for Generator

      Purpose of Generator Function 27 — Undervoltage Protection Undervoltage protection uses a measure of generator terminal voltage. Section 4.5.7 of IEEE Std. C37.102–2006, “Guide for AC Generator Protection,” describes the purpose of this protection as follows: &nbs...
  • 11kV / transformers / LV MCCs

        Power distribution systems used in large commercial and industrial applications can be complex. Power may be distributed through switchgear, switchboards,  transformers, and panelboards. Power distributed throughout a commercial  or industrial application is used for a va...