Exam (elaborations)
EWRB Theory Prep – MCBs: Questions With Solutions
- Course
- Institution
EWRB Theory Prep – MCBs: Questions With Solutions
[Show more]
Content preview
EWRB Theory Prep – MCBs: Questions With SolutionsTypes of MCB trips Right Ans – thermal magnetic
Thermal tripping Right Ans - bi-metal strip, used for overload currents
protection
Magnetic tripping Right Ans - magnetic inductor, used for short circuit
protection
Reset procedure Right Ans - reset to OFF
reset to ON
Arc containment includes Right Ans - horns carry current to chute, allow
arc to jump out
arc chute lengthens distance for arc to travel
oil suppresses arc
splitter plates split the arc
Arc control factors Right Ans - reduced horns width minimize arc x section
more plates split arc into multiple smaller voltages
maximize arc chute increases travel distance for arc
Four key parts of MCBs Right Ans - A. trip operating unit
B. control contacts unit
C. arcing ext. unit
D. frame unit
Describe (A. trip operating unit ) component function Right Ans - bi-
metal/mag. provides mechanism for detection of fault current and opens
contacts
Describe (B. control contacts unit ) component function Right Ans -
contacts allows the supply current to flow during normal running when MCB
is closed
Describe (C. arcing ext. unit ) component function Right Ans - all inclusive
factors - horns, chamber chutes, oils, splitter plates, used to control and
extinguish fault arc
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Zendaya. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $8.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
80796 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now