A 230 V shunt direct-current machine on no-load has a speed of 900 rpm and a...
A 230 V shunt direct-current machine on no-load has a speed of
900 rpm and a supply current of 2.5 A. The machine parameters
are:
• Field resistance: 230 Ω
• Armature resistance: 0.3 Ω
• Voltage drop/brush: 1.0 V (current independent)
a) Calculate the electromagnetic torque, speed, the output power
and the overall efficiency when the supply current is 35 A,
assuming that the friction and wind-age torque is constant. (16
points)
b) The machine operates now as generator and is driven to generate
35 A into the supply at 230 V and at 900 rpm. Determine the overall
efficiency. (6 points)
c) Calculate the extra field resistance required to make to make
the transition pos-sible from motor operation to generator
operation. (3 points)
Homework Answers
Add Answer to:
A 230 V shunt direct-current machine on no-load has a speed of
900 rpm and a...
A 230 V shunt direct-current machine on no-load has a speed of 900 rpm and a supply current of 2.5 A. The machine parameters are: • Field resistance: 230 Ω • Armature resistance: 0.3 Ω • Voltage drop/...
A 230 V shunt direct-current machine on no-load has a speed of 900 rpm and a supply current of 2.5 A. The machine parameters are: • Field resistance: 230 Ω • Armature resistance: 0.3 Ω • Voltage drop/brush: 1.0 V (current independent) a) Calculate the electromagnetic torque, speed, the output power and the overall efficiency when the supply current is 35 A, assuming that the friction and wind-age torque is constant. (16 points) b) The machine operates now as generator...
1. A shunt machine, while running as a generator, has an induced voltage of 260 V...
1. A shunt machine, while running as a generator, has an induced voltage of 260 V at 1200 rpm. Its armature and field resistances are 0.2 2 and 110 Q, respectively. If the machine is run as a shunt motor, it takes 4 A at 220 V (i) Draw the schematic diagram of the machine as a generator. (ii) Draw the schematic diagram of the machine as a motor (iii)At a certain load the motor takes 30 A at 220...
QUESTION 1 A) (10 marks) A 10 kW, 250 V DC self-excited shunt generator, with an...
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) The input current to a 220 V, short-shunt compound motor at no load is 6 A. The shunt- field c...
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 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. Calc...
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...
A DC shunt generator delivers a load current of 50 A at 300 V with its...
A DC shunt generator delivers a load current of 50 A at 300 V with its field circuit resistance being 50 ohms. The armature circuit resistance of the generator is 2 ohms The generator has a linear excitation with a constant rotor speed. The brush voltage drop is negligible. Aiding with a drawing of equivalent circuit, estimate: i) The field current, armature current and generated voltage of the generator when it delivers the 100 A at 300V; and (ii) The...
A 250 V, 10 KW, 1200 rpm dc shunt motor has a full load efficiency of...
A 250 V, 10 KW, 1200 rpm dc shunt motor has a full load efficiency of 80 percent. Its field and armature resistances are 110 ohms and .25 ohm respectively. Calculate the value of the resistance to be inserted in series with the armature and the power lost in the armature circuit to reduce the speed to 80 percent when the load torque is constant regardless of the speed.
3. A 25-kW, 230-V shunt motor has an armature resistance of 0.064 Ω and a field-circuit...
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...
A 6 hp, 180 V shunt dc motor draws a full-load current of 30 A from the power supply. The motor h...
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
Q1: (30 points) A shunt DC generator, running at a constant speed of 1400 rpm, has...
Q1: (30 points) A shunt DC generator, running at a constant speed of 1400 rpm, has a field resistance of 200 22 and armature resistance of 0.5 12. Ignore armature reaction and assume a 400 W rotational loss. a) [15] While supplying no load, the induced armature voltage is 280 V. Calculate the input power. b) [15] When the generator is loaded, the developed power is found to be 4.1 kW at the same magnetic flux of the field found...
1. A shunt machine, while running as a generator, has an induced voltage of 260 V at 1200 rpm. Its armature and field resistances are 0.2 2 and 110 Q, respectively. If the machine is run as a shunt motor, it takes 4 A at 220 V (i) Draw the schematic diagram of the machine as a generator. (ii) Draw the schematic diagram of the machine as a motor (iii)At a certain load the motor takes 30 A at 220...
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) 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 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...
A DC shunt generator delivers a load current of 50 A at 300 V with its field circuit resistance being 50 ohms. The armature circuit resistance of the generator is 2 ohms The generator has a linear excitation with a constant rotor speed. The brush voltage drop is negligible. Aiding with a drawing of equivalent circuit, estimate: i) The field current, armature current and generated voltage of the generator when it delivers the 100 A at 300V; and (ii) The...
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...
Q1: (30 points) A shunt DC generator, running at a constant speed of 1400 rpm, has a field resistance of 200 22 and armature resistance of 0.5 12. Ignore armature reaction and assume a 400 W rotational loss. a) [15] While supplying no load, the induced armature voltage is 280 V. Calculate the input power. b) [15] When the generator is loaded, the developed power is found to be 4.1 kW at the same magnetic flux of the field found...
Most questions answered within 3 hours.
-
An entomologist discovers a dung beetle rolling a ball of dung
along the ground, and decides...
asked 43 minutes ago -
Humans have used horses for transportation for millions of
years. Therefore, they will use horses for...
asked 2 hours ago -
The following are the Jensen Corporation's unit costs of making
and selling an item at a...
asked 3 hours ago -
Does direct Medicare reimbursement of Advanced practice nurses
increase access to their services?
asked 3 hours ago -
List and explain why a company would choose to use a
published
compensation survey vs. creating...
asked 4 hours ago -
A discrete random variable X can take values from 1 to 10. Find
the variance of...
asked 4 hours ago -
The primary financial goal of a corporation is to maximize:
shareholders wealth.
earnings per share.
stock...
asked 4 hours ago -
determine whether the vectors u=(1,2,3,), v=(-2,1,0) and
w=(1,0,1) are linearly dependent or independent.
asked 4 hours ago -
python
Define a function called print_values which takes a dictionary
object as a parameter. The function...
asked 5 hours ago -
In Chapter 1 you created a program named Triangle in
which you displayed a seven-line triangle...
asked 5 hours ago -
Research question: What are the differences between separately
stated and non separately stated transactions in an...
asked 5 hours ago -
By using Arduino write a code that connects two LEDs to two
push-buttons. Each button controls...
asked 6 hours ago