# Wk1 No Load DC Shunt Wound

```The shunt -wound DC machine
1
Experiments with the Shunt -wound DC Motor
❒ Experiment 1a : Commissioning of the shunt -wound DC machine
Experimental purpose:
Operate the shunt-wound machine as a motor.
Necessary equipment:
- Shunt-wound DC Machine (Type 2701)
- Brake Unit (Type 2719)
- Control Unit (Type 2730)
- Universal Power Supply (Type 2740)
- 2 multimeters
Experimental setup:
Universal Power Supply
(Type 2 7 4 0 )
Control Unit (Type 2 7 3 0 )
Armature
Field
205 V
0 ... 250 V
P1
P2
TK
PE
-
+
PE
IA
-
+
E2
E1
A
UA
V
A1
P1
PE
P2
TK
PE
M
3
M
Tx
Shunt- wound
DC Machine
Brake U nit (Type 2 7 1 9 )
(Ty pe 2 7 0 1)
Fig. 1.1 Experimental setup: Commissioning of the shunt-Wound
Machine
A2
The shunt-wound DC machine
Experimental procedure:
Observe the safety instructions!
Attention!
Set up the experiment as shown in Fig. 1.2.
Make sure that the exciting winding is connected
with the correct polarity!
Start up the system as already described in experiment 1.
Observe the setting of the torque attenuator.
Make sure that the field voltage is connected to the ex
citing winding.
Make sure that the exciting voltage is never inter
rupted during operation!
-
-
Set the armature voltage to the left stop (0 V).
Set the armature voltages asked for in Table
measure the speed n.
1.1 and
First switch off the Universal Power Supply and then
the Control Unit.
Measure the armature current and the armature voltage
at rated speed.
IA
=...
. . . A,
U =...
Draw the no -load characteristic in the prepared dia
gram Fig. 1.3. Determine the scale for UA yourself.
.V
A
Table 1.1.1.
Speed
UA / V
25
50
75
100
125
150
175
200
n / rpm
.
n /rpm
2000
1500
1000
500
0
A/V
istic of the shunt-wound motor
205
-
The shunt-wound DC machine
Evaluation:
Question 1:
What do you learn from the no-load characteristic in Fig.
1.3?
Question 2:
How high is the power consumed by the armature wind
ing at rated speed?