Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
thumb_up100%
Chapter 8, Problem 1SQ
To determine
Explain why contactors are described as control pilot devices and large magnetic switches.
Expert Solution & Answer
Explanation of Solution
Discussion:
Contactors are electromagnetic switches that are very convenient for interrupting and connecting the branch circuits based on the range or size of contractors.
Contactors with a combination of pilot devices are used to control AC motors, switch lightning, and heavy loads.
Small range contactors with a combination of control devices are used for larger controls. Large contactors can control the heavy currents where overload protection is provided separately. Relays might be used to control the large contactors.
Conclusion:
Thus, the reason why contactors are described as control pilot devices and large magnetic switches is explained.
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
Answer the following questions:
1- Write radiation resistance (R.) equation for infinitesimal dipole antenna.
2- Write the angle expression form of first null beam width (FNBW) for 2/2 dipole.
3- Define the Directivity of antenna.
4- Write radar cross section equation.
5- Write the input impedance (Z) expression of lossless transmission line.
The input reactance of an infinitesimal linear dipole of length 1/60 and radius
a = x/200 is given by
[In(/2a) - 11
X-120-
tan(kl/2)
Assuming the wire of the dipole is copper with a conductivity of 5.7 × 10'S/m.
determine at f = 1 GHz the
(a) loss resistance
(b) radiation resistance
(c) radiation efficiency
input impedance
Q4- a) For the block diagram of control system shown below with its unit step response. Determine
(K, a,damping ration, Maximum overshoot, Wn, Wd,ẞ, ts, tp, td, tr, and overall transfer function?
C(1) ↑
1.4
1.2
1
0.8
0.6
0.4
0.2
R(s)
E(s)
K
C(s)
$(s + α)
0.05
0.1
0.15
0.2
+2%
-2%
Chapter 8 Solutions
Electric Motor Control
Ch. 8 - Prob. 1SQCh. 8 - What is the principal difference between a...Ch. 8 - What causes the arc to move upward in a blowout...Ch. 8 - Why is it desirable to extinguish the arc as...Ch. 8 - Prob. 5SQCh. 8 - Why will the blowout coil also operate on AC?Ch. 8 - Prob. 7SQCh. 8 - Are ON control stations used in multiple locations...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.Similar questions
- Determine the power radiated for the antenna has the following specifications (48 ohm radiation resistance, 2 ohm loss resistance and 50 ohms reactance) connected to generator with 12 V open circuit and internal impedance 50 ohm via à long transmission line with 100 ohm characteristic impedance.arrow_forwardDon't use ai to answer I will report you answerarrow_forwardDon't use ai to answer I will report you answerarrow_forward
- Don't use ai to answer I will report you answerarrow_forwardThe former expert solved the question, but I didn't understand how he simplified the fractions. A communication satellite is in stationary (synchronous) orbit about the carch (assume altitude of 22.300 statute miles). Its transmitter generates 8.0 W. Assume the transmit- ting antenna is isotropic. Its signal is received by the 210-ft diameter tracking parabo- loidal antenna on the earth at the NASA tracking station at Goldstone, California. Also assume no resistive loss in either antenna, perfect polarization match, and perfect impedance match at both antennas. At a frequency of 2 GHz, determine the: (a) power density (in watts/m²) incident on the receiving antenna. (b) power received by the ground-based antenna whose gain is 60 dB.arrow_forwardDon't use ai to answer I will report you answerarrow_forward
- A communication satellite is in stationary (synchronous) orbit about the earch (assume altitude of 22.300 statute miles). Its transmitter generates 8.0 W. Assume the transmit- ting antenna is isotropic. Its signal is received by the 210-ft diameter tracking parabo- loidal antenna on the earth at the NASA tracking station at Goldstone, California. Also assume no resistive loss in either antenna, perfect polarization match, and perfect impedance match at both antennas. At a frequency of 2 GHz. determine the: (a) power density (in watts/m²) incident on the receiving antenna. (b) power received by the ground-based antenna whose gain is 60 dB.arrow_forwardDon't use ai to answer I will report you answerarrow_forwardA plane wave traveling in z-direction through a medium with &=8, μ-2 and has the electric and magnetic field intensity at z=0 shown in Fig. 6.1 and Fig. 6.2, respectively. Utilize the provided information to find the following: (a) w (b) The intrinsic impedance of the medium © B (d) a (e) The expression of the magnetic field intensity, H (f) The time-average power carried by the wave Magnetic Field Intensity (mA/m) Electric Field Intensity (V/m) 0.5 0.4- 0.3 0.2 ཧཱུྃ༔ཤྲུསྦྱ ཌུ ཋ ; སྟྲི " ° ཝཱ 0.1 -0.5 Ex -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 Fig 6.2 Hy 2.0 Time (ns)². -2.0 -1.5 -1.0 -0.5 0.0; 0.5 1.0 Time (ns) 2.0 0.083 ns or 0.0415 Tarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Electricity for Refrigeration, Heating, and Air C...Mechanical EngineeringISBN:9781337399128Author:Russell E. SmithPublisher:Cengage Learning
Delmar's Standard Textbook Of ElectricityElectrical EngineeringISBN:9781337900348Author:Stephen L. HermanPublisher:Cengage Learning
Electricity for Refrigeration, Heating, and Air C...
Mechanical Engineering
ISBN:9781337399128
Author:Russell E. Smith
Publisher:Cengage Learning
Delmar's Standard Textbook Of Electricity
Electrical Engineering
ISBN:9781337900348
Author:Stephen L. Herman
Publisher:Cengage Learning