Question

A 152 V DC shunt motor has an armature resistance of 0.3ohm, a brush voltage drop...

A 152 V DC shunt motor has an armature resistance of 0.3ohm, a brush voltage drop of 2 V, the rated full load current is 70 A.

A) calculate the current at the instant of starting as a percentage of full load current

B) calculate the value of starting resistance of limit the motor current at the instant of starting to 150 percent of the rated load current

Engineering   Electrical-Engineering   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A 200 V DC, 1,800 RPM shunt connected motor has an armature resistance of 0.4 ohm...
A 200 V DC, 1,800 RPM shunt connected motor has an armature resistance of 0.4 ohm and a brush resistance of 0.4 ohm; brush voltage drop of 6.0 V, independent of load. The resistance of the shunt field is 230 ohm. The full load rated line current is 40 A. When the motor is operated at no load the line current is 5 A and the speed is 1750 RPM. Calculate speed at rated load Calculate speed at .3 rated...
The full-load armature current of a 5 hp, 150 V shunt dc motor is 30 A....
The full-load armature current of a 5 hp, 150 V shunt dc motor is 30 A. The field (shunt) resistance and the armature resistance of the motor are ????F = 125 ? and ???????? = 0.15, respectively. At a random speed of 1800 rpm magnetization curve of the motor has measured and is shown in the table below. ????0 (V) armature voltage 10 90 110 140 170 185 ???????? (A) field (shunt) current 0 0.82 1 1.2 1.7 2.88 Calculate...
Question 2 The full-load armature current of a 5 hp, 150 V shunt dc motor is...
Question 2 The full-load armature current of a 5 hp, 150 V shunt dc motor is 30 A. The field (shunt) resistance and the armature resistance of the motor are ????F=125 ? and ????????=0.15, respectively. At a random speed of 1800 rpm magnetization curve of the motor has measured and is shown in the table below. EO(V) armature voltage 10 90 110 140 170 185 IF (A) field (shunt) current 0 0.82 1 1.2 1.7 2.88 Calculate the following: a....
A 5-kW, 220-V shunt motor has an armature resistance of 0.15 ? and a field-circuit resistance...
A 5-kW, 220-V shunt motor has an armature resistance of 0.15 ? and a field-circuit resistance of 100 ?. The motor delivers rated output power at rated voltage when its armature current is 20 A. When the motor is operating at rated voltage, the speed is observed to be 1000 r/min when the machine is loaded such that the armature current is 15 A. In order to protect both the motor and the dc supply under starting conditions, an external...
A 230-V DC shunt motor has armature circuit resistance of 0.25 ? and field circuit resistance...
A 230-V DC shunt motor has armature circuit resistance of 0.25 ? and field circuit resistance of 115 ?. At full load armature draws a current of 38 A and the speed is measured at 1050 rpm. Find the developed torque. The field rheostat is now changed so that total field resistance is 144 ?. Find the speed under this condition. Assume that the armature current does not change. Assuming the rotational losses amount to 600 W, find the efficiency...
Design of DC Motor Starter In order for a dc motor to function properly, it must...
Design of DC Motor Starter In order for a dc motor to function properly, it must be protected from physical damage during the starting period. At starting conditions, the motor is not rotating, and armature generated voltage EA = 0 V. Since the internal resistance of a normal DC motor is very low, a very high current flows. It is possible for a motor to be severely damaged by such currents, even if they last for only a moment. A...
Design of DC Motor Starter In order for a dc motor to function properly, it must...
Design of DC Motor Starter In order for a dc motor to function properly, it must be protected from physical damage during the starting period. At starting conditions, the motor is not rotating, and armature generated voltage EA = 0 V. Since the internal resistance of a normal DC motor is very low, a very high current flows. It is possible for a motor to be severely damaged by such currents, even if they last for only a moment. A...
A separate excited DC motor is running at 1000 rpm when the armature voltage is 600...
A separate excited DC motor is running at 1000 rpm when the armature voltage is 600 V. The motor has a field constant Kphi = 4 V.sec and the armature resistance of the motor is 0.8 Ohms. i. Calculate the value of the resistance of the dynamic braking at full load. The armature current should be limited to 200 % of the rated value. ii. If the motor operates in regenerative braking at a speed of 1200 rpm, calculate the...
A 100 hp, 250 V, 1200 rpm DC shunt motor with an armature resistance of 0.03...
A 100 hp, 250 V, 1200 rpm DC shunt motor with an armature resistance of 0.03 ? and a field resistance of 41.67 ?. The motor has compensating windings, so armature reactance can be ignored. Mechanical and core losses may be ignored also. The motor is driving a load with a line current of 126 A and an initial speed of 1103 rpm. The magnetization curve is shown in the following figure. 1. What is the motor speed if the...
In order for a dc motor to function properly, it must be protected from physical damage...
In order for a dc motor to function properly, it must be protected from physical damage during the starting period. At starting conditions, the motor is not rotating, and armature generated voltage EA = 0 V. Since the internal resistance of a normal DC motor is very low, a very high current flows. It is possible for a motor to be severely damaged by such currents, even if they last for only a moment. A solution to the problem of...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT