The power input to a dc shunt motor during rated-load conditions is 100 W. The rotor speed is 2000 r/min, and the armature voltage is 100 V. The armature resistance is 2? and Rf = 200 ?. Calculate the no-load rotor speed.
The power input to a dc shunt motor during rated-load conditions is 100 W. The rotor...
a) The input current to a 220 V, short-shunt compound motor at no load is 6 A. The shunt- field circuit resistance is 220 Ω; the armature resistance is 0.112, and the series-field resistance is 0.1 Ω, what is the stray power loss ? (b) Assume the input rating of the motor in Part (a) to be 66 A at 220 V with a no-load speed of 1000 rpm. If the stray power loss varies as the counter-electromotive force and...
A 6 hp, 180 V shunt dc motor draws a full-load current of 30 A from the power supply. The motor has a field (shunt) resistance of 150 Ω. The armature resistance of the motor is 0.1 Ω. When the motor speed is 1800 rpm (this is not the full-load speed), the relationship between the induced voltage
A 8250 w shunt DC motor has a terminal voltage of 300 V. A field resistance Rf of 40 Ω, and an armature resistance Ra of 250 mm2. The field winding has 1500 turns. An adjustable resistance Rad is connected in series to the field winding. Rad is set at 20 Ω, but it can vary from 0 to 80 Ω. The magnetization curve is shown in Figure.1 and it is taken at a speed of 1200 rpm. (Armature reaction...
Problem 3: DC machine A shunt DC motor rated at V,'. 300 V, with field resistance of Rf 600 0, armature 0.2 , resistance of R, 30.5 A (total current) when rated-load at n, consumes 916.8 rpm. Armature rotational loss (consisting of fan, friction and core loss (consisting of field resistance, armature a) Find Prot (rotational load), Pshaft and efficiency at rated load. - Assume that the rotational loss is constant and P,aft is now 50% in the case of...
3. A 25-kW, 230-V shunt motor has an armature resistance of 0.064 Ω and a field-circuit resistance of 95 Ω. The motor delivers rated output power at rated voltage when its armature current is 122 A. When the motor is operating at rated voltage, the speed is observed to be 1150 r/min when the machine is loaded such that the armature current is 69.5 A a. Calculate the rated-load speed of this motor In order to protect both the motor...
In a shunt-wound dc motor with the field coils and rotor connected in parallel (see the figure (Figure 1)), the resistance Rf of the field coils is Rf = 103 Ω and the resistance Rr of the rotor is Rr = 5.5 Ω. When a potential difference of V = 120 V is applied to the brushes and the motor is running at full speed delivering mechanical power, the current supplied to it is 4.90 A. Part A.) What is...
A shunt de motor is rated at 6kW, 120V and 1200 r/min has a magnetization curve as shown in Figure 1. The armature resistance is 0.189 and the field resistance is 2002 with and adjustable field resistance of 0 to 4002. The shunt de motor has rated line current of 50A when supplying rated voltage. (a) Determine the value of the adjustable field resistance so that the motor operates at no- load speed of 1200 r/min. [5 marks] (b) Assuming...
MESB443, Semester 1 2018/19 QUESTION 3 [10 marks) A 200V DC shunt motor develops a rated output power of Shp at 1000rpm, drawing 25A. Having Ra=0.50 and RF = 10092, find: a) The total rotational losses of the motor at rated conditions [4 marks] b) The no-load speed of the motor at 2001. [6 marks] Answer:
5.2. (15 pt.) A shunt DC motor has the following characteristics Prated 30 hp, Vt = 240 V; nated 1200 rpm Ra-0.19 Ω; Rs 0.02 2; Rotational losses at full load 3550 W rated= 110 A NF 2700 tums per pole NSE 12 turns per pole Radj 100 to 400 Ω 320 Speed = 1200 r/min 240 き 200 180 3 160 140 120 100 0 0. 0.2 0.3 04 0.5 0.6 0.7 0.8 0.9 1.0 1. 2 13 1.4...
A 30 hp, 240 V, 1150 rpm de shunt motor operating at rated conditions has an efficiency of 88.5%. The armature circuit resistance and field circuit resistance are 0.096 Ω and 936 Ω respectively. Calculate the following: (a) the armature current; b) the output torque (c) the mechanical developed power (d) the mechanical developed torque; and, e) the external resistance required in series with the armature to limit the starting torque to 200 % of rated torque. If the load...