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Overcurrent Protection
Rebecca Johnson, P.E.
Overview
An overcurrent is a current
that exceeds the amperage rating of the conductors (cable), equipment (motors,
instruments) or other devices in a circuit. Without adequate protection,
an overcurrent can damage conductors and equipment and potentially harm people.
Protection devices, such as fuses and circuit breakers, are installed in a
circuit to detect an overcurrent condition and selectively protect equipment and
personnel, while minimizing loss of power on the rest of the system.
However, the protection device must be properly selected to accommodate the
overcurrent and respond in the appropriate time frame.
In this course, the student
will study the types of overcurrents that may be encountered and the devices
available to afford protection against the overcurrent condition. This
course is relevant to electrical engineers seeking a refresher course in
overcurrent protection, as well as engineers in other disciplines who wish to
expand their knowledge in electrical engineering fundamentals.
The student must take a multiple-choice quiz consisting of
ten questions at the end of
this course to obtain PDH credits.
Specific Knowledge or Skill Attained
This course teaches the following specific knowledge and
skills:
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The definition of an
overcurrent and why protection is needed.
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Types of overcurrent
conditions, including overloads and short circuits.
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Causes of bolted fault,
arcing fault and ground fault short circuits.
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NEC requirements for
overcurrent protection.
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Design of overcurrent
protection devices, including fuses and circuit breakers.
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Location of overcurrent
protection devices to shield them from damage and to protect personnel and
surroundings.
Course
Click on the following PDF attachment and review the document
"Overcurrent Protection" prior to taking
a quiz for credit.
"Overcurrent Protection" (96 KB)
Having Trouble Downloading the PDF File?
Right click on the link. Select "Save Target As..."
Then save on your desktop. To view the file, double click the icon on your
desktop and return to this page to take the quiz.
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Click on the link below to download a free copy of Acrobat Reader.
To obtain PDH credits for this course, you will need to take a quiz for
credit. Click on the link below.
(To take the quiz,
your web browser must be set to accept cookies. See how to
check your cookie settings.)
 
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