Industrial Motor Control
7th Edition
ISBN: 9781133691808
Author: Stephen Herman
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 3, Problem 1RQ
A single-phase, 120 volt motor is controlled by a manual motor starter. The motor is not running, and the switch handle on the starter is found to be in the center position. What does this indicate?
Expert Solution & Answer
To determine
The indication of center position of switch handle of a manual motor starter.
Explanation of Solution
Manual motor starter is simple and common motor starter. Operator involvement is must to change the state of a manual motor starter. A manual motor starter is looks like a simple toggle switch. In addition, the manual motor starters are come up with overload protectors. Thus, the manual motor starter has three positions namely ON, OFF, and over load protection.
The two end positons of the toggle lever of a manual motor starter indicates ON and OFF positions. The center position indicates that the motor is tripped due to over load. Whenever the current flows in a circuit, a proportionate heat is generated in a conductor. When a motor is over loaded, more current will flow, heat generation is high. If this continues, the motor will fail. Thus, the overload heater (protector) is involved. The over load protector is designed for normal operating condition. When a motor runs abnormally (over loading), the over load protector stops the power supply to the motor. Thereby, the toggle lever (switch handle) moved to center position.
Hence, the center position of switch handle of a manual motor starter denotes that the motor is tripped due to over load.
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
7) Please draw the front, top and side view for the following object. Please cross this line out
A 10-kg box is pulled along P,Na rough surface by a force P, as shown in thefigure. The pulling force linearly increaseswith time, while the particle is motionless att = 0s untilit reaches a maximum force of100 Nattimet = 4s. If the ground has staticand kinetic friction coefficients of u, = 0.6 andHU, = 0.4 respectively, determine the velocityof the
A
1
0
-
kg box is pulled along P
,
N
a rough surface by a force P
,
as shown in the
figure. The pulling force linearly increases
with time, while the particle is motionless at
t
=
0
s untilit reaches a maximum force of
1
0
0
Nattimet
=
4
s
.
If the ground has static
and kinetic friction coefficients of u
,
=
0
.
6
and
HU
,
=
0
.
4
respectively, determine the velocity
of the particle att
=
4
s
.
Calculate the speed of the driven member with the following conditions:
Diameter of the motor pulley: 4 in Diameter of the driven pulley: 12 in Speed of the motor pulley: 1800 rpm
Chapter 3 Solutions
Industrial Motor Control
Ch. 3 - A single-phase, 120 volt motor is controlled by a...Ch. 3 - Prob. 2RQCh. 3 - Prob. 3RQCh. 3 - A push button manual starter has tripped on...Ch. 3 - What is meant by the term line voltage on some...Ch. 3 - Explain the difference between manual motor...Ch. 3 - Prob. 7RQCh. 3 - Prob. 8RQCh. 3 - Refer to the circuit shown in Figure 310. When...Ch. 3 - Prob. 10RQ
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
- 4. In the figure, shaft A made of AISI 1010 hot-rolled steel, is welded to a fixed support and is subjected to loading by equal and opposite Forces F via shaft B. Stress concentration factors K₁ (1.7) and Kts (1.6) are induced by the 3mm fillet. Notch sensitivities are q₁=0.9 and qts=1. The length of shaft A from the fixed support to the connection at shaft B is 1m. The load F cycles from 0.5 to 2kN and a static load P is 100N. For shaft A, find the factor of safety (for infinite life) using the modified Goodman fatigue failure criterion. 3 mm fillet Shaft A 20 mm 25 mm Shaft B 25 mmarrow_forwardPlease sovle this for me and please don't use aiarrow_forwardPlease sovle this for me and please don't use aiarrow_forward
- 3. The cold-drawn AISI 1040 steel bar shown in the figure is subjected to a completely reversed axial load fluctuating between 28 kN in compression to 28 kN in tension. Estimate the fatigue factor of safety based on achieving infinite life (using Goodman line) and the yielding factor of safety. If infinite life is not predicted, estimate the number of cycles to failure. 25 mm + 6-mm D. 10 mmarrow_forwardCORRECT AND DETAILED SOLUTION WITH FBD ONLY. I WILL UPVOTE 1. The truss shown is supported by hinge at A and cable at E.Given: H = 4m, S = 1.5 m, α = 75⁰, θ = 33⁰.Allowable tensile stress in cable = 64 MPa.Allowable compressive stress in all members = 120 MPaAllowable tensile stress in all members = 180 MPa1.Calculate the maximum permissible P, in kN, if the diameter of the cable is 20 mm.2.If P = 40 kN, calculate the required area (mm2) of member BC.3. If members have solid square section, with dimension 15 mm, calculate the maximum permissible P (kN) based on the allowable strength of member HI.ANSWERS: (1) 45.6 kN; (2) 83.71 mm2; (3) 171.76 kNarrow_forwardCORRECT AND DETAILED SOLUTION WITH FBD ONLY. I WILL UPVOTE 2: A wire 4 meters long is stretched horizontally between points 4 meters apart. The wire is 25 mm2 in cross-section with a modulus of elasticity of 200 GPa. A load W placed at the center of the wire produces a sag Δ.1.Calculate the tension (N) in the wire if sag Δ = 30 mm.2.Calculate the magnitude of W, in N, if sag Δ = 54.3 mm.3. If W is 60 N, what is the sag (in mm)?ANSWERS: (1) 562 N, (2) 100 N, (3) 45.8 Narrow_forward
- CORRECT AND DETAILED SOLUTION WITH FBD ONLY. I WILL UPVOTE 4 : A cable and pulley system at D is used to bring a 230-kg pole (ACB) to a vertical position as shown. The cable has tensile force T and is attached at C. The length of the pole is 6.0 m, the outer diameter is d = 140 mm, and the wall thickness t = 12 mm. The pole pivots about a pin at A. The allowable shear stress in the pin is 60 MPa and the allowable bearing stress is 90 MPa. The diameter of the cable is 8 mm.1.Find the minimum diameter (mm) of the pin at A to support the weight of the pole in the position shown.2.Calculate the elongation (mm) of the cable CD.3.Calculate the vertical displacement of point C, in mm.ANSWERS: (1) 6 mm, (2) 1.186 mm, (3) 1.337 mm--arrow_forward1. Derive an expression for H(w) filter or bandpass/reject filter. = for the circuit below. Qualitatively determine if it's a high/lowpass L ell R ww Voarrow_forward2. Obtain the transfer function, H(w) = 0 for the circuit below for R₁ = 1 kQ2, R2 = 10 kQ, and Vi C = 1 μF. What role, if any, does the capacitor play? Explain. R₁ R2 + C + Voarrow_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
Refrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning
Electrical Transformers and Rotating MachinesMechanical EngineeringISBN:9781305494817Author:Stephen L. HermanPublisher:Cengage Learning
Automotive Technology: A Systems Approach (MindTa...Mechanical EngineeringISBN:9781133612315Author:Jack Erjavec, Rob ThompsonPublisher:Cengage Learning
Understanding Motor Controls
Mechanical Engineering
ISBN:9781337798686
Author:Stephen L. Herman
Publisher:Delmar Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...
Mechanical Engineering
ISBN:9781305578296
Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:Cengage Learning
Electrical Transformers and Rotating Machines
Mechanical Engineering
ISBN:9781305494817
Author:Stephen L. Herman
Publisher:Cengage Learning
Automotive Technology: A Systems Approach (MindTa...
Mechanical Engineering
ISBN:9781133612315
Author:Jack Erjavec, Rob Thompson
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