5. A 20Kw dc shunt generator delivering rated output at 1000rpm has a terminal voltage of 500 V. The armature resistance is 0.1 ohm,voltage drop per brush is 1 V and the field resistance is 500 ohms. Calculate the speed at which this machine will run as a motor taking an input of 20 Kw from 500 V dc.

5. A 20Kw dc shunt generator delivering rated output at 1000rpm has a terminal voltage of 500 V. The armature resistance is 0.1 ohm,voltage drop per brush is 1 V and the field resistance is 500 ohms. Calculate the speed at which this machine will run as a motor taking an input of 20 Kw from 500 V dc.

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter29: Dc Generators

Section: Chapter Questions

Problem 1PA: You are working as an electrician in a large steel manufacturing plant, and you are in the process...

See similar textbooks

Similar questions

A squirrel-cage induction motor is operating at 1175 RPM and producing a torque of 22 Ib-ft. What is the horsepower output of the motor?
A 60-Hz, four-pole, three-phase induction motordelivers 35 kW of mechanical (output) power. At a certain operating point the machine has 4 percentslip and 87 percent efficiency. Determine thetorque delivered to the load and the totalelectrical (input) power consumed by themotor.
A d.c. shunt machine has armature and field resistances of 0.025 Ω and 80 Ω respectively. When connected to constant 400-V bus-bars and driven as a generator at 450 r.p.m., it delivers 120 kW. Calculate its speed when running as a motor and absorbing 120 kW from the same bus-bars
A d.c. series motor draws 25 A from a 260 V line while running at 900 rpm. It has an armature resistance of 1.5 Ω and a series field resistance of 0.8 Ω. A diverter is to be added to the circuit so that the speed increases to 1200 rpm while the line current increases to 30 A. Find the value of the diverter resistance Rd . a) find the Rd mathmatically
Refer here for the specifications of the D400. a) What power output should you be able to supply from the 24V D400 at 15.4 m/s? b) If the wind drops to 2 m/s, what will the output power be? c) According to the performance graph what is the maximum power you can obtain from the 24V D400? There is a possibility of installing the turbine on top of a 20m high mast instead. Assuming that Zo=0.012, what would you expect the wind speed to be at that height? Use wind shear formula and assume Vref = 7.5 m/s at a height of Zref =10 m.
A 13kV/50Hz/50MW generator is rotated at 750 rpm. The mechanical power loss of the system is %10 percent of the total mechanical power supplied to the generator. The generator is operated at full-load (i.e. output power is 50 MW). Find the output current of the generator and the torque applied by the mechanical system to the generator? If the electrical power is supplied to a load of 49 MW, what is percent electrical loss? Find also the total power loss from the mechanical system to the load.
Two dc shunt generators, each with armature resistance of 0.02 ohm and field resistance of 50 ohms run in parallel and supply a total current of 1000 A to the load circuit. If their emf's are 270 V and 265 V, solve the bus bar voltage. Subject:Electrical Machine 1
Q20) A 1000rpm DC shunt generator is supplying 100 lamps of 60W at 230V, the armature and field resistance are respectively 0.1Ω and 115Ω.Calculate the generated emf. a. 232.809 V b. 222.809 V c. 212.809 V d. 242.809 V
Two dc shunt generator in parallel supply together 2000A. The machines have armature resistances of 0.04 ohm and 0.025 0hm field resistance of 25 ohms and 20 ohms. The induced emf’s of 440 V and 420 V respectively. Find the output of each machine.
The armature and field resistances of a series machine are 0.2 ohm and 0.3 ohms respectively. While running as a generator, the generated emf is 250V at 1200rpm. If the machine is run as motor, it takes 4A at220V. At a certain load, the motor takes 30A at 220V. However, on load, the armature reaction weakens the field by 4%. Find the motor speed at this load.
A 10 Hp 220 V shunt motor takes a current of 3A when running light. Calculate the maximum efficiency as the motor when delivering full loadoutput if the armature and field resistances are 0.5 ohm and 250 ohmsrespectively.
(a) A d.c. shunt machine has armature and field resistances of 0.025 Ω and 80 Ω respectively. Whenconnected to constant 400-V bus-bars and driven as a generator at 450 r.p.m., it delivers 120 kW. Calculate itsspeed when running as a motor and absorbing 120 kW from the same bus-bars.(b) Deduce the direction of rotation of this machine when it is working as a motor assuming a clockwiserotation as a generator.