Exam (elaborations)
Electrical Chapter 8 Basic Electric Motors (Correctly Answered)
- Course
- Institution
Electrical Chapter 8 Basic Electric Motors (Correctly Answered)
[Show more]
Seller
Follow
Studyhall
Reviews received
Content preview
Electrical Chapter 8 Basic ElectricMotors (Correctly Answered)
magnetism ✔️ the physical phenomenon that includes the attraction
of an object for iron and is exhibited by a permanent magnet or an electric
current
Magnet poles ✔️ north and south
like poles repel and unlike poles... ✔️ attract
flux ✔️ the magnetic lines of force of a magnet that flow between the
north and south poles
magnetic field ✔️ the area that the magnetic force operates in
induced magnetism ✔️ created when a piece of iron is placed in a
magnetic field. The closer the object to the magnet the stronger the magnetic
field is on the object.
permanent magnet ✔️ a piece of magnetic material that been
magnetized and can hold its magnetic strength for a reasonable length of time.
electromagnet ✔️ a magnet produced through electricity
Motors ✔️ used to create a rotating motion and drive components
that need to be turned.
rotor ✔️ rotating part of an electric motor
stator ✔️ A stationary loop of wires around the rotor in which
electricity is produced.
What causes the rotor to move? ✔️ Changes in polarity (due to the
changing direction of AC) in the stator surrounding permanent polarity in the
rotor causing the stator poles to continuously repel and attract the poles of
the rotor causing continuous rotation of rotor
, Squirrel cage rotor ✔️ Most commonly used rotor today. Copper or
aluminum bars are evenly spaced in the steel portion of the rotor and
connected by an end ring. Produces an inductive magnetic field within itself
when stator is energized
Six general types of motors ✔️ shaded-pole, split-phase, permanent
split-capacitor, capacitor-start-capacitor run, capacitor-start, three-phase, and
electronically commutated.
Shaded pole motor starting torque ✔️ 100%
split-phase motor starting torque ✔️ 200%
psc motor starting torque ✔️ 200%
capacitor start capacitor run starting torque ✔️ 300%
three phase motor starting torque ✔️ 600%
electronically commutated motor starting torque ✔️ 200%
motor speed formula ✔️ flow reversals (frequency)/ second (hertz) x
120/ number of poles
open motor ✔️ has a housing and is used to rotate a device such as a
fan or a pump that is itself not enclosed in any type of housing
enclosed motor ✔️ housed with some type of shell. most common is
completely sealed hermetic compressor
shaded pole motors ✔️ uses a shaded pole made of a closed turn of a
heavy copper wire banded around a section of each stator pole
capacitor ✔️ consists of two aluminum plates with an insulator
between them. Used to boost the starting torque or running efficiency of
single phase motors
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 EFT, 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 this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Studyhall. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R222,96. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
82871 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now