27

Types , characters and practical application of D.C. motors

Starting of D.C. MOTORS

-3 point & 4 point starters

Study of the characters of D.C. Motors .

-study of 3 point & 4 point starters

-connection, starting, speed control of starters with motors

------do----

-------do-----

28

Types of speed control , their advantages & disadvantages & industrial application

Use of tachometers revolution counters with stop watch

Routine maintenance

Free hand isometric sketching of simple objects with dimension, Sketching of D.C. –4 point starter to scale

----do------

ACHIEVEMENT : 1 SHOULD BE ABLE TO IDENTIFY D.C.M./Cs

1. should be able to build up voltage in a D.C. generator
2. should be able to connect , test and run a D.C. Motor and reverse its direction of rotation by a starter

29&30
&31

Expl. of electrical wirings . importance. I.E.E. rules .

Types of wiring both domestic & industrial

Specification for wiring accessories – wires cables, buttons etc.

IS 732 –1963/5

Principle of laying out in domestic wiring testing by meggar

C.T.S. system

P.V.C. concealed system

Maintenance & Repairing data sheet preparation

Fixing of switches. Holder, plugs etc. the T.W. Board.

Identification and use of wiring accessories

Practice in C.T.S. wiring with minimum to more number of points

Use of two way switches

Testing of installation by meggar

Fixing of calling bells/buzzers

Making of test boards & extension boards

IS 732-1963/61

Repairing and testing of domestic electrical appliances

Freehand sketching of simple object. Layout arrangement of D.C. generators. Control panel

Do for motors

Meaning of stress, strain modules of elasticity, ultimate strength examples ]

Geometry –properties of lines, angles, triangles and circles,.

Factor of safety examples , types of stresses

32 &33

Specification, standards for conduits & accessories. Earthing, laying diagram for industrial conduit wiring

Identification & demonstration on conduits and accessories & their uses cutting & threading laying earthing, use of flexible conduit & testing by meggar

Measurement of earth resistance

Freehand sketching of plan, elevation , of hexagon , bar, sp. Bar , circular bar, tapered bar, staircase wiring

Simple problems on lines, angles , tri-angles and circles

ACHIEVEMENT ; SHOULD BE ABLE TO CARRYOUT SIMPLE WIRING CKT. UNDERTAKE, REPAIR OF DOMESTIC WIRINGS AND APPLICANCE

34&35

Comparison D.C. & A.C. advantages of A.C. Alternating current & related terms frequency, Instantaneous value, R.M.S. value Average value, Peak factor, Load factor. Generation of sine wave, phase, in phase out phase. Obstruction of A.C. ‘R’ X_L &

Impedance , power factor, Average power, reactive power, Reactive power

Simple problems of A.C. obstruction & T.P. A.P. etc.

Demonstration of sine wave, instantaneous values etc. Study of the behavior of R, X_L, & X_C in A.C. ckts, both in series and in parallel

Freehand sketching of simple geometrical shapes & hollow shapes

Drawing of simple electrical ckts. Using electrical symbols.

View of simple solid & hollow bodies.

Drawing of sine waves.

Effect of force on materials such application as expanding bending, twisting and shearing

Trigonometry-function use of trigonometric tables-applied problems

Mechanical advantages, velocity ratio, applied problems

36

Problems on A.C. ckts. Both series & parallel power consumption P.F. etc.

Concept of poly-phase star & Delta Connection Line Voltage & phase voltage, current power in a3 ph. Ckt.

Explanation on poly phase ckts. Current, voltage &power measurement in poly-phase ckts.

Measurement of energy in single & poly-phase ckts.

Views of simple solid and hollow bodies. Ckt. Diagram of battery charging ckts. With all details of panel board.

-do- Blue print reading.

Calculation of areas of triangles, polygons etc. with the aid of trigonometry.

37

Explanation of alternator prime/mover type advantages, parts, regulation, phase sequence, specification of alternators & practical places of uses

Demonstration on alternators parts voltage building , load character & regulation

Exercises on blue print reading of connection to motors through Ammeter, voltmeter & K.W. meters

Useful work of a machine mechanical efficiency of a machine –problems, further use of trigonometric function and applied problems.

Machines basic principle. Determination of velocity ratio, mechanical advantage & efficiency

38&39

Explanation & definition of transformer, classification C.T. , P.T. Instrument and auto/VARIAC construction, parts working E.M.F. equations efficiencies, parallel operation & poly phase types of their connection Cooling, protective devices . Specification simple problems on E.M.F. equation, turns ratio and efficiency. Special transformers

Identification of types of transformers. Connection of transformers efficiencies of transformers testing of transformer parallel operation of transformer. Use of C.T. & P.T. use of Instrument transformer

Exercises on Blue print reading, tracing the wiring diagram of a alternator & reproducing it in proper sequence with protective equipment sketching the synchroniser connections.

Free hand sketching of simple objects related to the trade.

Logarithms-Use of Logarithmic tables for multiplication & division. Determination of efficiency of simple m/cs. Like winch, pulley blocks, wheel and compound axle. Effects of electric current.

40

Explanation of A.C. motors , comparison with D.C. classification – pulsating field & split phasing. Working principle construction of 1-ph Motors characters

Identification of induction motors (I –ph-) squirrel cage type .

-split phase type

-capacitor type

slip ring type

starting of induction motor

Reversing

Dismantling Assembling

Diagram of connection to a squirrel cage induction motor. Sketching the connection diagram of controling & protective devices for induction , motors

Applied workshop problems involving , Use of logarithmic tables,. Different forms of energy, heat mechanical and electrical , conversion from one to another

41&42

Single phase motors contd. Split capacitors, repulsion and series motor working principle –parts- characters starting- running & reversing. Stepper motor & Universal

------do--------

Demonstration of stepper & universal motor

Development of winding diagram for a two pole D.C dynamo or motor

Preparation of working drawing from sketches..

plotting & reading of simple graphs

43 44&45

Explanation of Electrical measuring instruments

-types

-forces necessary to work instruments

-moving coil permanent magnet

-moving iron

-range extension

Multi Meter-

-wattmeter

-energy meter

-frequency meter

-calibration

Demonstration on scales on meters

-study of M.C.P.M. Meter

-do-M.I. meter

-do-Range extension

• -do-Wattmeter
• -do-Multi meter
• do-energy meter
• do-frequency meter
• do-calibration of meter

Sketching of simple objects related to trades.

Sketching of different shapes of coils

Further practice in blue print reading

Drawing development diagram for single phase A.C. motors

Meaning of Horse power & Brake horse power , Simple problems on work power & energy.’ calculation of volume, weight of simple solid bodies by using logarithm, Further problems on mensuration

46 47&48

Explanation of light white lights-illumination factors, intensity of light –importance of light. Human eye factor units

Types illumination & lamps

-Neon sign halogen

mercury vapour, sodium vapour, Flourescent tube.

-characters watt ages, fixing places. Types of lighting Decoration lighting – Drum switches, Direct & indirect lighting –efficiency in lumens per watt, colour available Thumb rule calculation of lumens.

Estimating placement of lights and fans and ratings Explanation of S.N. and R.N. LAMPS

Study of intensity of light

-do---Neon sign

-do-Mercury vapour (H.P. & L.P.)

--do-Sodium vapour

--do-Halogen lamps

-do-Single tube

Double tube

Practice in Decoration lighting –do-S.N. & R.N. lamps

Drawing the development diagram for D.C. Simplex lamps & Wave winding

. Rectifier Maximum Average current in rectifiers R.M.S. form factor ripple factor. .

49&50

Revision

Revision

Revision

Revision

51

Test

Test

Test

Test

ACHIEVEMENT

1. Test and connect domestic electric wiring and appliances
2. Carryout simple wiring in T.R.S. P.V.C wires on T.W. button
3. Install and test the lighting ckt.s in conduct system on T.W. button as per IE rules
4. Test & connect D.C. generators & motor & repair minor faults
5. Connect , run and reverse A.C. motors
6. Carryout decoration lighting