INDUSTRIAL TRAINING REPORT Held atNATIONAL FERTILIZERS LIMITED NAYA NANGAL

ROPAR(PB.) AN ISO 9001 14001 18001 UNITFROM 31 MAY 2011 TO 9 JULY 2011

Submitted to: Mr. N.K. Gupta

Submitted By: Akashdeep Singh Univ.Roll No.UE94003

UIET,PANJAB UNIVERSITY(CHD.)

INDUSTRIAL TRAINING REPORT Held atNATIONAL FERTILIZERS LIMITED NAYA NANGAL

ROPAR(PB.) AN ISO 9001 14001 18001 UNITFROM 31 MAY 2011 TO 9 JULY 2011

Submitted to: Mr. Gaurav Sapra

Submitted By: Akashdeep Singh Univ.Roll No.UE94003

UIET,PANJAB UNIVERSITY(CHD.)

ACKNOWLEDGEMENTI am extremely thankful to our college director Mrs. Renu Vig.My industrial training at National Fertilizers Limited,Nangal was the most practical and interesting experience. This industry is truly a mind opener for graduate engineers for their introduction to the industry in public sector. I am grateful to all the officers and technicians of instrumentation dept. for their guidance. I am also thankful to our Head of Dept. Mr. Y.P Verma. I am indebted to HRD of NFL,Nangal for their valuable guidance and help during the training period for selection of study material. Last but not least, I am Thankful to the whole Electrical Dept. For proper guidance and inspiration

AKASHDEEP SINGH UNIV. ROLL NO. UE94003 DEPT OF ELECTRICAL ENGG. UIET,PANJAB UNIVERSITY CHANDIGARH

INSTRUMENTS IN ELECTRICAL WORKSHOP1.AMMETER: An ammeter is a measuring instrument used to measure the electriccurrent in a circuit. Electric currents are measured in amperes (A), hence the name. Instruments used to measure smaller currents, in the milliampere or microampere range, are designated as milliammeters or microammeters.The ammeter generally used is moving coil ammeter. It uses magnetic deflection, where current passing through a coil causes the coil to move in a magnetic field. The modern form of this instrument was developed by Edward Weston (NOT the American photographer!), and uses two spiral springs to provide the restoring force. By maintaining a uniform air gap between the iron core of the instrument and the poles of its permanent magnet, the instrument has good linearity and accuracy. Basic meter movements can have full-scale deflection for currents from about 25 microamperes to 10 milliamperes and have linear scales. Moving iron ammeters use a piece of iron which moves when acted upon by the electromagnetic force of a fixed coil of wire. This type of meter responds to both direct and alternating currents (as opposed to the moving coil ammeter, which works on direct current only). The iron element consists of a moving vane attached to a pointer, and a fixed vane, surrounded by a coil. As alternating or direct current flows through the coil and induces a magnetic field in both vanes, the vanes repel each other and the moving vane deflects against the restoring force provided by fine helical springs The non-linear scales of these meters makes them unpopular.

Spring providing restoring force This illustration is conceptual; in a practical meter, the iron core is stationary, and front and rear spiral springs carry current to the coil, which is supported on a rectangular bobbin. Furthermore, the poles of the permanent magnet are arcs of a circle.

2.VOLTMETER: A voltmeter is an instrument used for measuring electricalpotential difference between two points in an electric circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage of the circuit; digital voltmeters give a numerical display of voltage by use of an analog to digital converter. A moving coil galvanometer can be used as a voltmeter by inserting a resistor in series with the instrument. It employs a small coil of fine wire suspended in a strong magnetic field. When an electric current is applied, the galvanometer's indicator rotates and compresses a small spring. The angular rotation is proportional to the current through the coil. For use as a voltmeter, a series resistance is added so that the angular rotation becomes proportional to the applied voltage. One of the design objectives of the instrument is to disturb the circuit as little as possible and so the instrument should draw a minimum of current to operate. This is achieved by using a sensitive ammeter or microammeter in series with a high resistance

Above diagrams show a voltmeter and its working

3.TRANSFORMER: A transformer is a device that transfers electrical energy fromone circuit to another through inductively coupled conductorsthe transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called mutual induction. If a load is connected to the secondary, an electric current will flow in the secondary winding and electrical energy will be transferred from the primary circuit through the transformer to the load. In an ideal transformer, the induced voltage in the secondary winding (Vs) is in proportion to the primary voltage (Vp), and is given by the ratio of the number of turns in the secondary (Ns) to the number of turns in the primary (Np) as follows:

Three phase step down transformer mounted between utility ports

BASIC PRINCIPLEThe transformer is based on two principles: first, that an electric current can produce a magnetic field (electromagnetism), and, second that a changing magnetic field within a coil of wire induces a voltage across the ends of the coil (electromagnetic induction). Changing the current in the primary coil changes the magnetic flux that is developed. The changing magnetic flux induces a voltage in the secondary coil. An ideal transformer is shown in the adjacent figure. Current passing through the primary coil creates a magnetic field. The primary and secondary coils are wrapped around a core of very high magnetic permeability, such as iron, so that most of the magnetic flux passes through both the primary and secondary coils.

4. AUTOTRANSFORMER: An autotransformer (sometimes called autoformer) isan electrical transformer with only one winding. The auto prefix refers to the single coil acting on itself rather than any automatic mechanism. In an autotransformer portions of the same winding act as both the primary and secondary. The winding has at least three taps where electrical connections are made.

OPERATIONAn autotransformer has a single winding with two end terminals, and one or more terminals at intermediate tap points. The primary voltage is applied across two of the terminals, and the secondary voltage taken from two terminals, almost always having one terminal in common with the primary voltage. The primary and secondary circuits therefore have a number of [ windings turns in common. Since the volts-per-turn is the same in both windings, each develops a voltage in proportion to its number of turns. In an autotransformer part of the current flows directly from the input to the output, and only part is transferred inductively, allowing a smaller, lighter, cheaper core to be used as well as requiring only a single winding One end of the winding is usually connected in common to both the voltage source and the electrical load. The other end of the source and load are connected to taps along the winding. Different taps on the winding correspond to different voltages, measured from the common end. In a step-down transformer the source is usually connected across the entire winding while the load is connected by a tap across only a portion of the winding. In a step-up transformer, conversely, the load is attached across the full winding while the source is connected to a tap across a portion of the winding.

A SINGLE PHASE TAPPED AUTOTRANSFORMER 5.ENERGY METER: An electricity meter or energy meter is a device that measuresthe amount of electric energy consumed by a residence, business, or an electrically powered device. Electricity meters are typically calibrated in billing units, the most common one being the kilowatt hour. Periodic readings of electric meters establishes billing cycles and energy used during a cycle. The most common type of electricity meter is the electromechanical induction watt-hour meter. The electromechanical induction meter operates by counting the revolutions of an aluminium disc which is made to rotate at a speed proportional to the power. The number of revolutions is thus proportional to the energy usage. It consumes a small amount of power, typically around 2 watts. The metallic disc is acted upon by two coils. One coil is connected in such a way that it produces a magnetic flux in proportion to the voltage and the other produces a magnetic flux in proportion to the current. The field of the voltage coil is delayed by 90 degrees using a lag coil.This produces eddy currents in the disc and the effect is such that a force is exerted on the disc in proportion to the product of the instantaneous current and voltage. A permanent magnet exerts an opposing force proportional to the speed of rotation of the disc. The equilibrium between these two opposing forces results in the disc rotating at a speed proportional to the power being used. The disc drives a register mechanism which integrates the speed of the disc over time by counting revolutions, much like the odometer in a car, in order to render a measurement of the total energy used over a period of time.

A Three phase electromechanical energy meter