Exam (elaborations)
NCCER Electrical Level 2 Module 2 Motors: Theory and Application With 100% SURE ANSWERS
- Course
- Institution
NCCER Electrical Level 2 Module 2 Motors: Theory and Application With 100% SURE ANSWERS
[Show more]
Seller
Follow
Content preview
JACKLINENCCER Electrical Level 2 Module 2 Motors: Theory and
Application With 100% SURE ANSWERS
Terms in this set (91)
Magnetic lines of force are continuous and always form closed loops; Magnetic lines of force
How DC motors operate?
do not cross.
Armature The rotating windings of a DC motor.
Commutator A device used on electric motors or generators to maintain a unidirectional current.
_ __ is produced by mounting a loop in a fixed magnetic field and as long as the fields of the
Torque
magnet and armature interact.
The rated output capacity of the motor. It is based on breakdown torque, which is the
horsepower
maximum torque a motor will develop without an abrupt drop in speed.
A____ is produced by the fields poles, and a loop of wire in the armature turns and cuts this
magnetic field
magnetic field.
NCCER Electrical Level 2 Module 2 Motors: Theory and Application
1/7
, 10/9/24, 1:24 PM
Shunt
Types of DC motors Series
Compound
Types of AC motors Synchronous and Induction (Single and Polyphase)
Periodic duty: (Definition) Intermittent operation at a substantially constant load for a short and definitely specified time.
The approximate full-load speed at the rated power line frequency. The speed of a motor is
Revolutions per minute (rpm)
determined by the number of poles in the winding.
For single-phase motors, the standard rotation, unless otherwise noted, is counterclockwise
Rotation facing the lead or opposite shaft end. All motors can be reconnected at the terminal board for
opposite rotation unless other wise indicated.
The speed of the revolving field of the stator, which is dependent on the supply frequency and
Synchronous speed
number of poles in a stator winding.
Field poles The stationary portion of a DC motor that produces the magnetic field.
The principle reason for developing the eliminate commutator problems
brushless DC motor was to ___.
The electrical energy required to produce 1hp of 746W
mechanical energy is _.
When there is a wide variation in both torque series DC motor
and speed requirements, such as a blower or
hoist, use a _.
The name of the stationary motor part that stator
produces the magnetic field during operation is
the ____.
The rpm of a 60Hz motor with two poles is ___. 3,600rpm
In three-phase motors, the rotor most commonly squirrel cage rotor
used is the _ _.
The starting torque characteristics of a wound- rotor resistance
rotor motor are defined by _.
A three-phase synchronous motor is started with amortisseur winding
a(n) __ _. NCCER Electrical Level 2 Module 2 Motors: Theory and Application
2/7
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 Queenstin. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.49. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67866 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now
