Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
22 Cards in this Set
- Front
- Back
In a separately excited gen. Where does the field excitation current come from |
An external power source |
|
What are the 2 circuits of a separately excited gen called? |
The field and armature |
|
How is a magnetic field produced in a field coil? |
Current must pass through it |
|
What type of gen shunt configuration is shown? |
Long |
|
In a DC series gen |
Current flows only when there is a load |
|
What is used to control exciter output voltage level? |
The strength of the shunt field |
|
When an elevator travels faster in the up direction when it is fully loaded than it does when empty is ------- compounded? |
Over compounded |
|
Which is correct about a shunt generator |
Its output drops as load is increased |
|
What is correct about a cumulative-compounded generator? |
The series field aids the shunt field |
|
What is the gen series field connected in parallel with? |
Series field shunt |
|
How is motor speed changed |
By changing the field or armature voltage |
|
What type of gen uses 2 fields |
Compound gen |
|
What is a series field connected in series with? |
The armature |
|
What is correct about an exciter field circuit? |
Its self excited |
|
What is the method for use if final acceleration step for a hoist motor? |
Weaken the shunt field |
|
What is the method for use if final acceleration step for a hoist motor? |
Weaken the shunt field |
|
In a dampening motor control, what is the rate of acceleration of the hoist motor depent on? |
The rate at which cemf builds up in the dampening motor |
|
What circuit is used for preventing build up of current when the gen field is de-energized? |
Suicide circuit |
|
What type of compounding when gen rated load voltage is less than the no load voltage |
Under compounded |
|
The speed of a DC motor depends on armature voltage an ------? |
Field strength |
|
The speed of a DC motor depends on armature voltage an ------? |
Field strength |
|
A ------- gen pole pieces become excited by residual magnetism |
Self excited generator |