Electrical World

Voltages Stabilizer                 All electrical and electronic system are designed and manufactured to operate at maximum efficiency with a given supply voltage called the Nominal operating Voltage .                 For various reasons the voltage of the energy distribution does not remain constant,showing considerable fluctuations in the nominal value,which leads to the apparatus ,not only a loss of efficiency but all a significant increase in failure rate.                  The stabilizer are electronics devices responsible for correcting the voltage of the electrical power supply to provide a stable and secure power supply to equipment , allowing for a stable voltage of the problem of the mains.The out put voltage from the stabilizer will stay in the range of 220v or 230v in case of single phase supply and 380v to 400v in case of three phase su...

Introduction                 Variable frequency drive (VFD) or adjustable frequency drive(AFD),Variable -voltage/Variable frequency(VVF) drive,Variable speed drive(VSD),AC drive,Micro drive or inverter derive is a type of adjustable speed drive used in electro-mechanical drive system to control AC motor speed and torque by varying motor input frequency and voltage. Working Of VFD                  The first stage of a variable frequency AC drive or VFD is the converter.The converter is comprised of six diodes used in plumbing system.They allow current to flow in only one direction the direction shown by the arrow in the diode symbol..For example whenever A Phase voltage (voltage is similar to pressure in plumbing system) is more positive than B or C phase voltages,  then the B-phase diode will open and allow current to flow .When B -phase become more positive than A -phase then the B-...

History Of Circuit Breaker                  An early form of circuit breaker was described by Thomas Edison in an 1879 patent application , although his commercial power distribution system used fuses.Its purpose was to protect lighting circuit wiring from accidental short circuits and overloads. Installation Of First Circuit Breaker                The BOSTON Electric light company in 1898 used the first installed breaker at the local     L Train Station. Working Principle Of Circuit Breaker                Circuit Breaker essentially consists of fixed and moving contacts .Whenever a fault occurs on any part of the system,the trip coil of the breaker gets energized and the moving contacts are getting apart from each other by some mechanism , thus opening the circuit. Design Of Circuit Breaker For Given Load   ...

History of Fuse                     A french Physicist Namel Breguet was famous for his effort in the initial days of telegraphy.He suggested the utilization of reduced part of conductors to guard telegraph stations against the hits of lighting with liquefying , the slighter wires would guard equipment along with wiring in the building . In the year 1864, lighting installation and telegraph cables can be protected by employing a variety of foil fusible essentials and wires, Finally , Thomas Alva Edison has patented a fuse as an element of his electric distribution system in the year 1890. Principle of Fuse                    Fuses are sacrificial devices used to protect much more expensive electrical components from the damaging effects of overcurrent.Fuses consist of a low Resistance metal or wire that is used to close a circuit.When too much current flows through the low...

Principle                            Relays are switches that open and close circuits electromechanically or electronically. Relay control one electrical circuit by opening and closing contacts in another circuit.                         Normally open and Normally closed                        When a relay is normally open (NO) there is an open contact when a relay is not energized .When a relay is normally closed (NC) there is a closed contact when the relay is not energized. The state of relay will change when we apply the electrical current to the contact.  Uses of Relay                        Relays are generally used to switch smaller current in a control circuit and do not usually control power consuming dev...

                                                                               The transformer is said to be in parallel operation when their primary windings are connected to a common voltage supply and the secondary windings are connected to a common load. Advantages of Parallel Operation     It increases the reliability of supply system.  The size of transformer increases with the increase of its rating,its transportation and instalation is difficult.On the other hand transportation and instalation of small size transformers are easy. One ore more transformers may be taken under maintenance and the remaining will supply the load.  Disadvantages of Parallel Operation   Increasing short circuit current that increase breaker capacity. Bus rat...