A 220 V DC shunt motor has an armature resistance, Re-0.1 S2, a field resistance, Ry=100...
1. A 300 V compound motor has armature resistance 0.18 Ω, series field resistance 0.3 Ω and shunt field resistance 100 Ω. The rotational losses are 200 W. On full load the line current is 25 A and the motor runs at 1800 rpm. Determine: (i) the developed mechanical power (ii) the output power (iii) the output torque (iv) the efficiency at full load 2. A 120 V series motor has 0.2 Ω field resistance. On full load, the line...
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...
220 v dc shunt motor has Ra= 0.25 ohms and Rf=120 ohms . At no-load the motor draws a current It=6A. And runs at 1500 rpm. At full-load the motor draws 62 A. the armature reaction at full load reduces the flux by 10%. Determine the rotational losses , motor speed at full-load, the shaft torque and efficiency.
QUESTION 1 A) (10 marks) A 10 kW, 250 V DC self-excited shunt generator, with an armature resistance of 0.1 ohm, is delivering 80 % of rated power to the mains at rated voltage when being run at 1000 r.p.m. (revolutions per minute). The field circuit resistance is 220 ohms. The brush contact drop is 0.5 V and rotational (mechanical) losses are 750 W Calculate The induced voltage The electromagnetic torque developed The shaft torque The overall efficiency B) (15...
A 240V DC shunt motor runs at 800rpm at no load. Determine the resistance to be placed in series with the field so that the motor runs at 950rpm when taking an armature current of 20A. The field resistance is 1600 and armature resistance is 0.40. Assume that the pole flux is proportional to the field current Additional Rf= A 240V DC shunt motor runs at 800rpm at no load. Determine the resistance to be placed in series with the...
FQ3 3. A 240 V DC series motor with 0.1 ohm armature resistance and 0.1 ohm field resistance runs at 1200 rpm and 100 Amp. of full load speed and armature current respectively. The motor has a brush contact drop of 2 volts. Find the motor full load torque and efficiency If the motor is to drive a pump that requires a torque of 150 NM, find the speed as the motor drives the given pump. a. b.
Show all working 1. A 4 pole, 220 V, 10 H.P, d.c. shunt motor is rotating at a speed of 320 rpm. Then the developed useful torque is 2. A 4 pole, lap wound d.c. motor drawing an armature current of 20 A has 360 conductors. If the flux per pole is 0.015 Wb then the gross torque developed by the armature of motor is 3. A 220 V, d.c. motor draws an armature current of 20 A. Its armature...
An armature-controlled dc motor operates at steady state, with an armature drive voltage va = 10 V. The motor runs at 600 rpm, and the armature current is found to be ia = 0.2 A. The armature resistance is Ra = 15 Ω. Determine: (a) The torque constant km of the motor (b) Electrical damping constant be (c) The efficiency under the given operating conditions, if the mechanical damping constant is bm = 8.25 × 10−5 N ⋅ m/rad/s (d)...
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...
1. A 4 pole, 220 V, 10 H.P, d.c. shunt motor is rotating at a speed of 320 rpm. Then the developed useful torque is a.210.647 N-m b.215.547 N-m c.219.484 N-m d.None of these 2. A 4 pole, lap wound d.c. motor drawing an armature current of 20 A has 360 conductors. If the flux per pole is 0.015 Wb then the gross torque developed by the armature of motor is a.10.23 N-m b.15.56 N-m c.17.17 N-m d.19.08 N-m 3....