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ELECTRICIAN - CITS


                                       MODULE 6: DC Generator and DC Motor


           EXERCISE 30 & 34 : To identify the parts of DC Generator


            Objectives

           At the end of this exercise you shall be able to
           •  dismantle and reassemble of DC Generator
           •  identify the parts of DC Generator
           •  measure the resistance of field coils & armature
           •  check & identify the terminals of DC Generator.

           Requirements

           Tools/Equipments
           •  Combination Plier (165 mm,                        •   Rubber mallet 0.5 kg        - 1 No.
              insulated)                      - 1 No.          •   Old DC compound Generator
           •   Screw Driver set 150mm, 5 blades   - 1 Set         250 V DC                      - 1 No.
                                                                                    1/2
           •   Neon tester 75mm, 500V         - 1 No.          •   Multi meter Digital, 3  digit   - 1 No.
           •  Electrician knife Insulated     - 1 No.          Materials
           •   Spanner set 6 to 32 mm         - 1 Set          •  Test lamp 60 W, 230 V         - 1 No.
           •   Allen key set 4 to 8 mm        - 1 Set          •   Emery paper                  - 1 Sheet
           •   Ball peen hammer 0.5 Kg        - 1 No.          •   Cotton waste / cloth         - as reqd.
           •   Bearing puller                 - 1 No.

            Procedure

           TASK 1:  Read and note the name plate details of DC Generator
           1  Clean the given DC generator with cotton waste.
           2  Read the name plate and record the specifications of DC generator
           3  Place the DC Generator on wooden table and make a mark on both sides of end covers & yoke.


           TASK 2: Dismantling the DC Generator.

           1  Unscrew the assembly nut bolts & screws of DC Generator with spanner / Allen key
           2  Remove the both side end covers of DC Generator.
           3  Disconnect the terminals of field coils, armature.
           4  Carefully remove the carbon brushes from the commutator.

           5  Carefully take out the armature assembly without damaging field coils.

           TASK 3: Identify the parts of DC Generator and reassemble.

           1  Identify the parts of DC Generator, viz- Yoke, Armature, commutator, brush, field poles & coils.
           2  Measure the resistance of field coils and armature with multi meter.
           3  Check the Generator terminals in terminal box.
           4  Reassemble the DC Generator properly.
           5  Check the mechanical assembly, free rotation of shaft and friction if any.

           6  Clean the machine and keep it in proper place.
           Safety precautions:
           1  Use proper tools for disassembling & assembling the DC Generator.


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