Understanding Motor Controls
4th Edition
ISBN: 9781337798686
Author: Stephen L. Herman
Publisher: Delmar Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Question
Chapter 34, Problem 1RQ
To determine
Identify whether varying the voltage of an AC induction motor changes the synchronous speed.
Expert Solution & Answer
Explanation of Solution
Synchronous speed:
The speed at which the magnetic field rotates in a motor is called the synchronous speed. The synchronous speed is given by the following formula:
s=120fP
Here, the synchronous speed in RPM is s, the frequency in Hz is f, and the number of stator poles per phase is P.
The two factors that determine the synchronous speed of the motor are given below:
- The number of stator poles per phase.
- The frequency of the applied voltage.
Hence, the synchronous speed will change only when the frequency of the applied voltage is changed and not the quantity of voltage. Changing the voltage will change the motor running speed. However, the running speed is not the synchronous speed.
Want to see more full solutions like this?
Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
1.1 m
1.3 m
B
60-mm diameter
Brass
40-mm diameter
Aluminum
PROBLEM 2.52
-
A rod consisting of two cylindrical portions AB and BC is restrained at both
ends. Portion AB is made of brass (E₁ = 105 GPa, α = 20.9×10°/°C) and
portion BC is made of aluminum (Ę₁ =72 GPa, α = 23.9×10/°C).
Knowing that the rod is initially unstressed, determine (a) the normal
stresses induced in portions AB and BC by a temperature rise of 42°C, (b)
the corresponding deflection of point B.
30 mm
D
=
40 MPa
-30 mm
B
C
80 MPa
PROBLEM 2.69
A 30-mm square was scribed on the side of a large steel pressure
vessel. After pressurization, the biaxial stress condition at the square
is as shown. For E = 200 GPa and v=0.30, determine the change in
length of (a) side AB, (b) side BC, (c) diagnonal AC.
Please solve in detail this problem
thank you
Chapter 34 Solutions
Understanding Motor Controls
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- 0,5 mm 450 mm 350 mm Bronze A = 1500 mm² E = 105 GPa प 21.6 × 10-PC Aluminum A = 1800 mm² £ = 73 GPa = a 23.2 × 10-PC PROBLEM 2.58 Knowing that a 0.5-mm gap exists when the temperature is 24°C, determine (a) the temperature at which the normal stress in the aluminum bar will be equal to -75 MPa, (b) the corresponding exact length of the aluminum bar.arrow_forward0.5 mm 450 mm -350 mm Bronze Aluminum A 1500 mm² A 1800 mm² E 105 GPa E 73 GPa K = 21.6 X 10 G < = 23.2 × 10-G PROBLEM 2.59 Determine (a) the compressive force in the bars shown after a temperature rise of 82°C, (b) the corresponding change in length of the bronze bar.arrow_forwardThe truss shown below sits on a roller at A and a pin at E. Determine the magnitudes of the forces in truss members GH, GB, BC and GC. State whether they are in tension or compression or are zero force members.arrow_forward
- A weight (W) hangs from a pulley at B that is part of a support frame. Calculate the maximum possible mass of the weight if the maximum permissible moment reaction at the fixed support is 100 Nm. Note that a frictionless pin in a slot is located at C.arrow_forwardIt is the middle of a winter snowstorm. Sally and Jin take shelter under an overhang. The loading of the snow on top of the overhang is shown in the figure below. The overhang is attached to the wall at points A and B with pin supports. Another pin is at C. Determine the reactions of the pin supports at A and B. Express them in Cartesian vector form.arrow_forwardRecall that the CWH equation involves two important assumptions. Let us investigate how these assumptions affect the accuracy of state trajectories under the control inputs optimized in (a) and (b). (c.1): Discuss the assumptions about the chief and deputy orbits that are necessary for deriving CWH.arrow_forward
- PROBLEM 2.50 1.8 m The concrete post (E-25 GPa and a = 9.9 x 10°/°C) is reinforced with six steel bars, each of 22-mm diameter (E, = 200 GPa and a, = 11.7 x 10°/°C). Determine the normal stresses induced in the steel and in the concrete by a temperature rise of 35°C. 6c " 0.391 MPa 240 mm 240 mm 6₁ = -9.47 MPaarrow_forwardFor some viscoelastic polymers that are subjected to stress relaxation tests, the stress decays with time according to a(t) = a(0) exp(-4) (15.10) where σ(t) and o(0) represent the time-dependent and initial (i.e., time = 0) stresses, respectively, and t and T denote elapsed time and the relaxation time, respectively; T is a time-independent constant characteristic of the material. A specimen of a viscoelastic polymer whose stress relaxation obeys Equation 15.10 was suddenly pulled in tension to a measured strain of 0.5; the stress necessary to maintain this constant strain was measured as a function of time. Determine E (10) for this material if the initial stress level was 3.5 MPa (500 psi), which dropped to 0.5 MPa (70 psi) after 30 s.arrow_forwardFor the flows in Examples 11.1 and 11.2, calculate the magnitudes of the Δ V2 / 2 terms omitted in B.E., and compare these with the magnitude of the ℱ terms.arrow_forward
- Calculate ℛP.M. in Example 11.2.arrow_forwardQuestion 22: The superheated steam powers a steam turbine for the production of electrical power. The steam expands in the turbine and at an intermediate expansion pressure (0.1 MPa) a fraction is extracted for a regeneration process in a surface regenerator. The turbine has an efficiency of 90%. It is requested: Define the Power Plant Schematic Analyze the steam power system considering the steam generator system in the attached figure Determine the electrical power generated and the thermal efficiency of the plant Perform an analysis on the power generated and thermal efficiency considering a variation in the steam fractions removed for regeneration ##Data: The steam generator uses biomass from coconut shells to produce 4.5 tons/h of superheated steam; The feedwater returns to the condenser at a temperature of 45°C (point A); Monitoring of the operating conditions in the steam generator indicates that the products of combustion leave the system (point B) at a temperature of 500°C;…arrow_forwardThis is an old practice exam question.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Understanding Motor ControlsMechanical EngineeringISBN:9781337798686Author:Stephen L. HermanPublisher:Delmar Cengage Learning
Electrical Transformers and Rotating MachinesMechanical EngineeringISBN:9781305494817Author:Stephen L. HermanPublisher:Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning
Understanding Motor Controls
Mechanical Engineering
ISBN:9781337798686
Author:Stephen L. Herman
Publisher:Delmar Cengage Learning
Electrical Transformers and Rotating Machines
Mechanical Engineering
ISBN:9781305494817
Author:Stephen L. Herman
Publisher:Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...
Mechanical Engineering
ISBN:9781305578296
Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:Cengage Learning
Mechanical Design (Machine Design) Clutches, Brakes and Flywheels Intro (S20 ME470 Class 15); Author: Professor Ted Diehl;https://www.youtube.com/watch?v=eMvbePrsT34;License: Standard Youtube License