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Electrical Engineering Principles (EET 211)
Laboratory Module
EXPERIMENT 4
Characteristics of DC Shunt Motor on No-Load Condition
Objective
To study and understand the characteristics of DC Shunt Motor on No-Load condition
Introduction
The shunt motor is different from the series motor in that the field winding is connected
in parallel with the armature instead of in series. Since the field winding is placed in
parallel with the armature, it is called a shunt winding and the motor is called a shunt
motor. Figure 1.0 below shows a diagram of a shunt motor. The field terminals are
marked Fl and F2, and the armature terminals are marked Al andA2.
Figure 1.0 Shunt Motor
Equipment and Parts
1. Starting Resistor Module (NO-5302)
2. Field Resistor Module (NO-5301).
3. Power Supply Module (NO-5306)
4. DC Voltage/ Ammeter Module (NO-5308)
5. Machine Field Frame Module (NO-5310)
6. DC Graphic Board (NO-5313)
7. Winding Rotor (A05).
8. Pole piece for magnetic Field Winding (A10)
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Electrical Engineering Principles (EET 211)
Laboratory Module
9. Field Winding/700 turn (A14)
10. B type Brush Holder (A17)
11. Rotor Shaft (A20)
12. Magnetic pole shaft (A21)
13. Fixing Bolt (A22)
14. 8mm Spannar (A24)
Procedure
1. Install all the related parts and equipment as shown in Figure 2.0. Ensure all items
are correct by referring its respective party number.
2. Connect all the wirings accordingly to Figure 2.0. Before switching on the power
supply, ensure that Starting Resistance (NO-5302) and Field Rheostat (NO-5301) are
set at its maximum value.
3. Turn on the power supply. Set the field resistance value by turning clockwise the
knob of Field Rheostat (NO-5301) to a value of 40 ohm (indicated by the knob).
4. Set the Starting Resistance (NO-5302) to 30ohm, 27.5ohm, 25ohm, 22.5ohm and
20ohm step-by-step (indicated by the knob). For every value of starting resistance,
measure the steady-state armature current, IA and steady-state/normal running speed of
the rotor (N).
5. Repeat procedure no 4 for field rheostat (NO-5301) of 45ohm and 50ohm respectively.
6. Record all your data in Table1.0.
7. Now, set and fix Starting resistance value, Ra (NO-5302) value to 25ohm. Vary Field
Rheostat Rf (NO-5301) from 25ohm, 30ohm and 35ohm step-by-step. For every value of
field resistance Rf, measure the normal running speed of the rotor (N) and the steadystate field current (If).
8. Repeat procedure no 7 for starting resistance value (NO-5302) of 30ohm and 35ohm
respectively. Record all your data in Table 1.1.
9. From Table 1.0, plot a graph of Speed (N) against armature current (IA).
10. From Table 1.1, plot a graph of Speed (N) against field current, If.
11. Observe the graphs that you have plotted and for each of them and explain the
related characteristics of the motor.
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Electrical Engineering Principles (EET 211)
Laboratory Module
Figure 2.0
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Electrical Engineering Principles (EET 211)
Laboratory Module
EXPERIMENT 4
Characteristics of DC Shunt Motor on No-Load Condition
Name: ______________________________
Group: ____________
Matric No: _______________
Date: ______________
Answer:
Q.6
Field Resistance,
Starting
Rotor Speed, N
Armature Current,
Rf (ohm)
Resistance, RA
(RPM)
IA (A)
(ohm)
Table 1.0
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Electrical Engineering Principles (EET 211)
Laboratory Module
Q.8
Starting Resistance,
Field Resistance,
Rotor Speed ,N
Field Current,
RA, (ohm)
Rf , (ohm)
(RPM)
If (A)
Table 1.1
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Electrical Engineering Principles (EET 211)
Laboratory Module
Q.11
Conclusion:
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