Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 2, Problem 1SQ
If the contacts on a manual starter cannot be closed immediately after a motor overload has tripped them open, what is the probable reason?
Expert Solution & Answer
To determine
Explain the probable reason for allowing the time duration to reset the starter contacts after they tripped off by the overload protection equipment of the motor.
Explanation of Solution
Discussion:
The overload protection of the motor trips off (open) the contacts of a motor starter when the load exceeds the normal range. The overload protection equipment (heater) gets heated during the overload condition.
The contacts of the starter can reset only after the overload protection equipment cools completely. If the contacts are closed immediately, the heater does not cool properly due to the insufficient time and it lead to damage the motor as the overload still exists.
Conclusion:
Thus, the contacts of the motor starter cannot close immediately when the motor overload has tripped them open.
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
Please do NOT answer if you are going to use AI. Please give a proper solution.
P7.2
The capacitors in the circuit shown below have no energy stored in them and then switch "A"
closes at time t=0. Switch "B" closes 2.5 milliseconds later. Find v(t) across the 6 μF
capacitor for t≥ 0.
500 Ω
B
4 µF
20 V
6 µF 7
Σ2 ΚΩ
25 mA
+
· με
Q1: If x[n] is a discrete signal and represented by the following
equation, what is the value of x[0] and X[-2]
Q2:
{x[n]}={-0.2,2.2,1.1,0.2,-3.7,2.9,...}
a- Assuming that a 5-bit ADC channel accepts analog input ranging
from 0 to 4 volts, determine the following:
1- number of quantization levels;
2-step size of the quantizer or resolution;
3- quantization level when the analog voltage is 1.28 volts.
4- binary code produced by the ADC.
5- quantization error.
b- Determine whether the linear system is time invariant or not?
1 1
y(n) = x(n)
Q3: Evaluate the digital convolution of the following signals using
Graphical method. Find: y(0) to y(3)
Q4:
2, k = 0,1,2
2, k = 0
h(k)
0
1, k = 3,4 and x(k)
elsewhere
=
1,
k = 1,2
0
elsewhere
The temperature (in Kelvin) of an electronic component can be
modelled using the following approximation:
T(t) [293+15e-Ju(t)
A digital thermometer is used to periodically record the component's
temperature, taking a sample every 5 seconds.
1- Represent the…
Chapter 2 Solutions
Electric Motor Control
Ch. 2 - If the contacts on a manual starter cannot be...Ch. 2 - If the handle of an installed motor starter is in...Ch. 2 - How may an automatic operation be achieved when a...Ch. 2 - What does the term trip-free mean as it relates to...Ch. 2 - Prob. 5SQCh. 2 - Prob. 6SQCh. 2 - Prob. 7SQCh. 2 - Prob. 8SQCh. 2 - Select the best answer for each of the following....Ch. 2 - Select the best answer for each of the following....
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
- I need solution by hand clearlyarrow_forwardfin D Q Point 7.57 in Matlab Aarrow_forwardFor the following graphical figure, write the function x(n) and h(n) in: 1. sequential vector 2. functional representation 3. Tabular 2 h0) 32 If signal x(n)-(32130 104032)], describe this signal using: 1. Graphical representation 2. Tabular representation 3. Write its expression 4. Write it as equation 5. Draw it as y(n) - x(n) u(n-3) 6. Sketch it if it is bounded at -2arrow_forwardA wattmeter is connected with the positive lead on phase “a” of a three-phase system. The negative lead is connected to phase “b”. A separate wattmeter has the positive lead connected to phase “c”. The negative lead of this wattmeter is connected also to phase “b”. If the input voltage is 208 volts line-to-line, the phase sequence is “abc” and the load is 1200 ohm resistors connected in “Y”, what is the expected reading of each of the wattmeters? (Hint: draw a phasor diagram)arrow_forwarda b 1 ΚΩΣ 56002 82092 470Ω Rab, Rbc, Rde d e O 470Ω Σ 5 Ω 25$ 5602 3 4 Ωarrow_forwardMY code is experiencing a problem as I want to show both the magnitude ratio on low pass, high pass, and bandbass based on passive filters: Code: % Define frequency range for the plot f = logspace(1, 5, 500); % Frequency range from 10 Hz to 100 kHz w = 2*pi*f; % Angular frequency % Parameters for the filters (you can modify these) R = 1e3; % Resistance in ohms (1 kOhm) C = 1e-6; % Capacitance in farads (1 uF) L = 10e-3; % Inductance in henries (10 mH) % Transfer function for Low-pass filter: H_low = 1 / (1 + jωRC) H_low = 1 ./ (1 + 1i*w*R*C); % Transfer function for High-pass filter: H_high = jωRC / (1 + jωRC) H_high = 1i*w*R*C ./ (1 + 1i*w*R*C); % Transfer function for Band-pass filter: H_band = jωRC / (1 + jωL/R + jωRC) H_band = 1i*w*R*C ./ (1 + 1i*w*L/R + 1i*w*R*C); % Plot magnitude responses figure; subplot(3,1,1); semilogx(f, 20*log10(abs(H_low))); % Low-pass filter title('Magnitude Response of Low-pass Filter'); xlabel('Frequency (Hz)'); ylabel('Magnitude (dB)'); grid…arrow_forwardarrow_back_iosSEE MORE QUESTIONSarrow_forward_ios
Recommended textbooks for you
Electricity for Refrigeration, Heating, and Air C...Mechanical EngineeringISBN:9781337399128Author:Russell E. SmithPublisher:Cengage Learning
Electricity for Refrigeration, Heating, and Air C...
Mechanical Engineering
ISBN:9781337399128
Author:Russell E. Smith
Publisher:Cengage Learning
Single Phase Induction Motor, How it works ?; Author: Lesics;https://www.youtube.com/watch?v=awrUxv7B-a8;License: Standard Youtube License