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 Fig. 1.3 No-load characterU 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? Answer: Calculation: