Concept explainers
Whether the motor in Figure 35-1 is started in medium or high speed and explain why.
Answer to Problem 1SQ
No, the motor in Figure 35-1 cannot be started in medium or high speed.
Explanation of Solution
Refer to Figure 35–1 in the textbook shows the push-button speed selection for a wound rotor motor permits three steps of speed. In this circuit, the motor must be allowed to start at low speed and progress to second speed and then, to high speed. When the motor is operating at high speed, the motor speed can be reduced to a slower speed by pushing the suitable speed push button.
The motor is started at low speed by pressing a low speed push button and the coil M gets energized. This causes the power to be supplied to the stator winding of motor through the load contacts M. Due to that, the motor starts slowly with full resistance available in the secondary circuit. In Figure 35-1, the motor cannot be started in high or medium because it is interlocked with the low push button and the maintaining contact M.
Conclusion:
Thus, the motor in Figure 35-1 cannot be started in medium or high speed.
Want to see more full solutions like this?
- 1. A 230 V shunt motor takes a total current of 25 A. If the field winding resistance is 100N and the amature resistance of 0.30, Determine the Current in the armature and Back emf I need all steps , write clear pleasearrow_forwardA 220 V shunt motor driving its normal load draws an armature current of 50 A from a 220 V dc source. The armature resistance of this motor including brushes is 0.25 ohms. How much armature current (minimum) Will this motor draw from a 200 V DC source when driving the same load with the field adjusted to maintain the same speed.arrow_forwardAnswer al or else skiparrow_forward
- 1. A 100 v dc series motors run at 400 rpm when taking a current of 55 Amp. Armature resistance is 0.03 ohm, field resistance is 0.03 ohm. If the load torque remains the same. What is the input current when the field is shunted by a resistor of 0.02 ohm? 2. A four-pole lap wound 500 V shunt motor takes a full-load armature current of 50A, the full-load speed being 800 r.p.m. There are 440 armature conductors and armature resistance is 0.3 ohm, contact drop brush = 1 V.Find the useful flux per pole.arrow_forwardJustify with suitable diagrams why reluctance motor is termed as variabletorque motor and hysteresis motor as constant torque motor.arrow_forwardExplain any one type of enclosure used in DC motors with necessary diagramarrow_forward
- PLEASE ANSWER QUİCKLYarrow_forwardA 500-Volt shunt motor running at 720 rpm takes an armature current of 50A. The effective armature resistance is 0.4 ohms. What resistance must be placed in series with the armature to reduce the speed to 600 rpm? The torque remains constant.arrow_forwardAnswer please in 10 minutesarrow_forward
- An induction motor develops rated torque with a slip of 3.5% when the rotor is cold. If the rotor resistance is 20% higher when the motor is at normal running temperature, at what slip it will develop rated torque?arrow_forwardWhich of the following types of DC motors are typically controlled by a DC drive? Chose all that apply Group of answer choices brush-less DC shunt series permanent magnet compoundarrow_forward8.A. One characteristic of a typical universal motor is that itA. is usually designed for low-speed operation.B. has a low locked-rotor torque.C. operates at about the same speed on a-c and doc circuits. 8.B. A centrifugal starting switch in a split-phase motor operates on the principle thatA. a high starting current opens the switch contacts.B. a higher speed changes the shape of a disk to open the switch contacts.C. the actuating weights move outward as the motor slows down.arrow_forward
Delmar's Standard Textbook Of ElectricityElectrical EngineeringISBN:9781337900348Author:Stephen L. HermanPublisher:Cengage Learning