Page 255 - CITS - Electrician - Trade Practical

ELECTRICIAN - CITS

EXERCISE 97 : Demonstrate Wiring of Motors

Objectives

At the end of this exercise you shall be able to
• read name plate data and estimate wiring accessories for motor
• draw the wiring diagram of motor
• demonstrate the wiring of motor.

Requirements

Tools/Instrument Tools/Instrument
• Insulated combination pliers 150 mm - 1 No. • AC induction machine 3ɸ,0.5 Hp,415 V - 1 No.
• Screw driver 100,150,200mm - 1 No Each. • DOL starter 1-2A,415 V - 1 No.
• D.E. spanner set 5mm - 30mm - 1 Set.
• Side cutting plier 150 mm - 1 No. Materials
• Screw driver 150 mm - 1 No. • IThree core flexible cable 1.5 mm 2 - 5 m.
• Connector screw driver 100 mm - 1 No.
• Measuring tape steel 3 m - 1 No.
• Electric hand drill machine 1 - 16 mm - 1 No.
• Drill bit 1 - 10 mm - 1 No Each.
Procedure

TASK 1:
1 Record the name plate data

Sl.No Description Value Remark
1 Name of the machine
2 Make
3 Model

4 Rated Voltage
5 Rated frequency
6 Rated speed
7 Rated capacity
8 Rated current
9 Insulation class
10 Type of connection

TASK 2:
1 Calculate the current of the motor by multiplying with a factor of 3 for three phase squirrel cage induction motor
full voltage start motor.

I = HP X 735.5/(1.73 X 415 X 0.85 X.8) assuming efficiency of 85% and pf 0.8
2 Select cable for connections.
3 Select starter suiTable for the motor.
4 Assess the selected Starter for its contactor rating and set Over load relay.
5 Prepare the layout with room dimensions
6 Draw the circuit diagram. (Fig 1)

238