Quantcast
WORKING ON CIRCUIT BREAKERS

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
2-39 The TIME DELAY RATINGS of circuit breakers are INSTANTANEOUS, SHORT TIME DELAY, and LONG TIME DELAY. SELECTIVE TRIPPING is used to cause the circuit breaker closest to the faulty circuit to trip, isolating the faulty circuit without affecting other nonfaulty circuits. This is accomplished by using an instantaneous circuit breaker close to the load, a short time delay circuit breaker at the next junction, and a long time delay circuit breaker at the main junction box. The FACTORS used to select a circuit breaker are the power requirements of the circuit and the physical space available. When WORKING ON CIRCUIT BREAKERS, the following items should be done BEFORE working on the circuit breaker: Check the applicable technical manual, obtain the approval of the electrical or engineering officer (for shipboard circuit breakers), remove power from the circuit breaker, and tag the switch that removes power from the circuit breaker. The following items should be checked and discrepancies corrected when working on circuit breakers: Check the operating mechanism for smooth operation, check the contacts for pitting, check the terminals for tightness and corrosion, check the mounting hardware for tightness and wear, check all components for wear, and check the entire circuit breaker for cleanliness. ANSWERS TO QUESTIONS Q1. THROUGH Q43. A1.   To protect people and circuits from possible hazardous conditions. A2.   A direct short, excessive current, and excessive heat. A3.   A condition in which some point in the circuit where full system voltage is present comes in contact with the ground or return side of the circuit. A4.   A condition that is not a direct short but in which circuit current increases beyond the designed current carrying ability of the circuit. A5.   A condition in which the heat in or around the circuit increases to a higher than normal level


Electrical News
ON Semi on a Roll With Image Sensors
Coupled with the company's acquisition of Truesense last week and...
eetimes.com
Wearable Computing Market on 78% CAGR Through 2018
By the end of 2014, shipments of wearable devices are...
eetimes.com
EEVblog Server Issues
The EEVblog dedicated server which hosts this site and the...
eevblog.com
EEVblog #604 – Sinclair C5 Restoration – Part 1
The obligatory “before” video showing Dave’s Sinclair C5 electric “car”...
eevblog.com
Samsung, Glofo Roll 14nm Process
Putting heat on TSMC, Samsung and Globalfoundries are putting a...
eetimes.com
The Big Fat Indian Election
Technology and data analysis have come to play a crucial...
eetimes.com
Are PCB Layout Designers an Endangered Species?
Are PCB layout designers as a group poised to fade...
eetimes.com
Motorola People, Products Remembered
As some of the last big chunks of Motorola going...
eetimes.com
10 Space Exploration Trends to Watch
The machines continue to perform splendidly across the solar system....
eetimes.com
Samsung's Galaxy S5 BOM Tops $250
IHS has estimated that the Samsung Galaxy S5 smartphone carries...
eetimes.com
Current Status of the Robot Apocalypse From EE Live! 2014
Max has supreme confidence that seeing a "genuine counterfeit moustache"...
eetimes.com
How the Heartbleed Bug Performs Its Nefarious Activities
I have to say that this is the clearest explanation...
eetimes.com
Correlated Electron Memory Claims From 4DS
Ron Neale takes a closer look at 4DS Inc.'s reported...
eetimes.com
Google Contact Lens Patent Points to More Wearables
In a filing from the US Patent office, Google is...
eetimes.com
Google Unveils Modular Phone
Mod is back, according to officials from Google's Project Ara...
eetimes.com
Galaxy 5 Shows Innovation Slowing
Samsung's Galaxy 5 shows innovation in smartphones is shifting from...
eetimes.com
Registration Opens for Microchip's MASTERs Conference
This conference is a great chance to meet Microchip's subject-matter...
eetimes.com
AllJoyn: A Common Language for Internet of Things
Open-source lingua franca aims to let IoT devices and services...
eetimes.com
Faster Cryptocurrency Mining With Digital Power
Mining for digital currency has created the latest race for...
eetimes.com
Micron Workers Approve Italian Jobs Deal
The deal between Micron and its Italian workforce will save...
eetimes.com
   


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +