Lab 6 - INTRODUCTORY LAB by gjjur4356

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									Electrical and Electronic Principles – EECE2330


                                         Lab 6 – DC Motor Tagging

Purpose: The purpose of this lab is to tag a DC motor, wiring it as a series, shunt and compound.

The lab will go slowly as the instructor must be present at your station whenever power is on. Please
be patient. Prior to starting any lab, confirm that power is off at your station by checking that the
disconnect switch is in the off position.

Procedure:
1) Identify the six leads from your DC motor. Each motor is provided with both series and shunt field
    windings. Use an ohmmeter to find each pair of leads, and measure their resistance AT THE
    TERMINAL STRIP. In the following tables, enter the terminal numbers for S1, S2, F1, F2, A1 and
    A2.
    A DC motor will have armature windings, and may have a series winding or a shunt winding or both.
    The motors in this lab have all three. Since the shunt winding is many turns of small diameter wire, it
    will have a higher resistance than the others (200 – 300 ohms). The series field and armature will have
    lower resistances (1 – 5 ohms). The series field and armature resistance values will be similar. To
    discriminate between the two, spin the motor shaft while measuring the resistance value. Field
    resistance may change a bit, but armature resistance will change a lot as the motor is spun.

2)   Identify and record the terminal numbers for the drum controller.

                +                   -
                                                   Station #
                                                   Lead            Terminal Block #             Resistance
                                                   Positive V                                   na
                                                   Negative V                                   na
 Drum
Controller                                         A1
                                                   A2
                                                   S1
                                                   S2
                                                   F1
                Shunt Winding
                                                   F2

                F1             F2

                          Series Winging
                                                                              Drum Controller
                                                                         TERM #          TERM #
         A1          A2    S1           S2                                       A    D


                                                                                 B    E


                                                                                 C    F




3) Record the nameplate data of your motor.

RPM __________________________                       Amps _________________________

HP (Watts) _____________________                     Other __________________________



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Electrical and Electronic Principles – EECE2330



4) In the area below, draw a schematic for wiring the motor as a series-wound motor. Be sure to include
   terminal numbers.




5) Do the wiring as per your schematic.

6) After you have completed the wiring shown above, WITH THE POWER OFF, check for resistance
   across the supply while manually closing the drum controller. If you note an open circuit, or dead short
   across the line, you must trouble-shoot your circuit before testing with power.

                                             Record the resistance between your power terminals. _______

7) Have your instructor review your wiring. Correct as required.
8) When ready, contact the lab instructor. Be sure all tools are on the shelf, and not in the electrical
    raceway containing the terminal blocks. DO NOT ATTEMPT ANY WIRING CHANGES WHEN
    LIVE.
9) Advise the students on each side of you that power is being applied at your station.
10) Close the fuse-box, and move the disconnect up to the closed position with your left hand, while
    looking away from the box.
11) Start the motor using the drum controller. Only jog (run) the motor briefly.
12) Turn off the disconnect switch. Turn off the station breaker. Open the disconnect door.

13) If the motor was not rotating in the “standard direction of rotation” , (clock-wise looking at the back of
    the motor), the best solution is to interchange the armature leads (reverse the terminal numbers in your
    diagram). If required, with the instructor present, test the motor rotation again. Confirm “standard
    rotation”.
14) Turn off the disconnect switch. Turn off the station breaker. Open the disconnect door.
15) Make a sketch of the motor speed during the start sequence by listening to its response.




16) HAVE THE INSTRUCTOR CONFIRM COMPLETION OF THIS PART OF THE LAB.
                               (Instructor’s Initial – on the submission sheet)



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Electrical and Electronic Principles – EECE2330



17) In the area below, draw a schematic for wiring the motor as a shunt-wound motor. Be sure to include
    terminal numbers.




18) Do the wiring as per your schematic.
19) After you have completed the wiring shown above, do a resistance check as you did previously.

                                            Record the resistance between your power terminals. _______

20) Have your instructor review your wiring. Correct as required.
21) Contact your lab instructor to power the board, and test motor operation. Only jog (run) the motor
    briefly.
22) Turn off the disconnect switch. Turn off the station breaker. Open the disconnect door.
23) If the rotation is wrong this time, you will interchange the shunt field wire leads not the armature
    leads. Note that changing the armature leads would cause a differential connection when connecting
    the motor as a compound motor. Don’t forget to update your diagram.
24) With the instructor present, test the rotation again.
25) Turn off the disconnect switch. Turn off the station breaker. Open the disconnect door.
26) Make a sketch of the motor speed during the start sequence by listening to its response.




27) HAVE THE INSTRUCTOR CONFIRM COMPLETION OF THIS PART OF THE LAB.

                                            (Instructor’s Initial – on the submission sheet)



Lab 6 - DC Motor Tagging.doc                                                                     Page 3 of 8
Electrical and Electronic Principles – EECE2330


28) In the area below, draw a schematic for wiring the motor as a compound-wound motor. Be sure to
    include terminal numbers.




29) Do the wiring as per your schematic.
30) After you have completed the wiring shown above, do a resistance check as you did previously.

                                              Record the resistance between your power terminals. _______

31) Have your instructor review your wiring. Correct as required.
32) Contact your lab instructor to power the board, and test motor operation. Only jog (run) the motor
    briefly.
33) Turn off the disconnect switch. Turn off the station breaker. Open the disconnect door.
34) If you have tagged the motor windings properly the motor should rotate in the “standard direction of
    rotation”. Discuss the problem with your instructor. Make your modifications as required. Don’t forget
    to update your diagram.
35) With the instructor present, test the rotation again.
36) Turn off the disconnect switch. Turn off the station breaker. Open the disconnect door.
37) Make a sketch of the motor speed during the start sequence by listening to its response.




38) HAVE THE INSTRUCTOR CONFIRM COMPLETION OF THIS PART OF THE LAB.

                                              (Instructor’s Initial – on the submission sheet)

39) Prior to leaving class, please remove all wiring and return all tools to their proper locations.



Lab 6 - DC Motor Tagging.doc                                                                           Page 4 of 8
Electrical and Electronic Principles – EECE2330



                                       Lab 6 – DC Motor Tagging
                                           Submission Sheet

Name:___________________________________


Station #
Lead            Terminal Block #             Resistance                      Drum Controller
Positive V                                   na                         TERM #          TERM #
                                                                                  A     D
Negative V                                   na
A1                                                                                B     E

A2
                                                                                  C     F
S1
S2
F1
F2



1.   Record the nameplate data of your motor.

RPM __________________________                       Amps _________________________

HP (Watts) _____________________                     Other __________________________


2.   In the area below, draw a schematic for wiring the motor as a series-wound motor. Be sure to include
     terminal numbers.




Record the resistance between your power terminals. _______




Lab 6 - DC Motor Tagging.doc                                                                     Page 5 of 8
Electrical and Electronic Principles – EECE2330


3.   Make a sketch of the motor speed during the start sequence by listening to its response.




4.   HAVE THE INSTRUCTOR CONFIRM COMPLETION OF THIS PART OF THE LAB.

                                                      (Instructor’s Initial – Series completed _________)


5.   In the area below, draw a schematic for wiring the motor as a shunt-wound motor. Be sure to include
     terminal numbers.




Record the resistance between your power terminals. _______

6.   Make a sketch of the motor speed during the start sequence by listening to its response.




7.   HAVE THE INSTRUCTOR CONFIRM COMPLETION OF THIS PART OF THE LAB.

                                                      (Instructor’s Initial – Shunt completed _________)




Lab 6 - DC Motor Tagging.doc                                                                     Page 6 of 8
Electrical and Electronic Principles – EECE2330


8.   In the area below, draw a schematic for wiring the motor as a compound-wound motor. Be sure to
     include terminal numbers.




Record the resistance between your power terminals. _______

9.   Make a sketch of the motor speed during the start sequence by listening to its response.




10. HAVE THE INSTRUCTOR CONFIRM COMPLETION OF THIS PART OF THE LAB.

                                                (Instructor’s Initial – Compound completed _________)




Lab 6 - DC Motor Tagging.doc                                                                    Page 7 of 8
Electrical and Electronic Principles – EECE2330


                                           Marking Scheme

        /2 Lab completed and demonstrated to the instructor.

        /2 Terminal numbers and name plate information.

        /2 Series wound schematic, power terminal resistance and speed profile.

        /2 Shunt wound schematic, power terminal resistance and speed profile.

        /2 Compound wound schematic, power terminal resistance and speed profile.

        /-1 Title page

        /-1 Neatness

        /10 Total




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