Neiep 400 final study guide
0.49k ohm converted - ANS-490 ohms
AC induction motor - ANS-
Basic loop circuit, the generator armature supplies the DC power to what DC elevator hoist
motor component? - ANS-Motor armature
Before using a megger, what must be done? - ANS-Isolate
Brush holders should be positioned no more than what distance above the commutator? -
ANS-3/32"
Calculating transformer efficiency % - ANS-EP x IP= A ES x IS= B
Divide A and B
Do you have to disconnect wires when using a clamp on meter? - ANS-No
How do you restore magnetism to an exciter? - ANS-Flashing the field (battery)
How to use precision shunts? - ANS-Requires the the circuit under test is open and the shunt
inserted (in series with the load)
If your meter readings appear incorrect, what do you do? - ANS-Compare with a known good
meter
The primary has 600 turns, the second has 200, and it has 120 volts. What is the secondary
voltage? - ANS-NP over NS. VP over VS
600 over 200. 120v over ?
120x200= 24,000
24,000 divided by 600=40vs
What are the 4 things that make up the commutator film? - ANS--copper oxide
-vapor of water -graphite particles
-graphite film
What can you use to detect a ground in armature coils? - ANS-Ohms meter
What circuit is used for preventing build-up of circulating current when the generator field is
de-energized? - ANS-Suicide
What color should a commutator be? - ANS-Chocolate brown
ANS-Generator: What transforms mechanical energy into electrical energy What is saturation?
- ANS-When no more magnetic lines can be produced.
415 pg 6
What is synchronous speed? - ANS-The rotational speed of the stators magnetic field on an
Induction motor.
What is the % of slip of a 60Hz 4 pole motor that rosters at 1745rpm? - ANS-3.05%
Sync rpm- rotor rpm x100
Divided by sync rpm
What is the action in the elementary DC generator of converting AC to DC called? -
ANS-Commutation
What is the field protective relay in series with? - ANS-Safety circuit
What is the purpose of interpoles? - ANS-They prevent neutral plane shift
0.49k ohm converted - ANS-490 ohms
AC induction motor - ANS-
Basic loop circuit, the generator armature supplies the DC power to what DC elevator hoist
motor component? - ANS-Motor armature
Before using a megger, what must be done? - ANS-Isolate
Brush holders should be positioned no more than what distance above the commutator? -
ANS-3/32"
Calculating transformer efficiency % - ANS-EP x IP= A ES x IS= B
Divide A and B
Do you have to disconnect wires when using a clamp on meter? - ANS-No
How do you restore magnetism to an exciter? - ANS-Flashing the field (battery)
How to use precision shunts? - ANS-Requires the the circuit under test is open and the shunt
inserted (in series with the load)
If your meter readings appear incorrect, what do you do? - ANS-Compare with a known good
meter
The primary has 600 turns, the second has 200, and it has 120 volts. What is the secondary
voltage? - ANS-NP over NS. VP over VS
600 over 200. 120v over ?
120x200= 24,000
24,000 divided by 600=40vs
What are the 4 things that make up the commutator film? - ANS--copper oxide
-vapor of water -graphite particles
-graphite film
What can you use to detect a ground in armature coils? - ANS-Ohms meter
What circuit is used for preventing build-up of circulating current when the generator field is
de-energized? - ANS-Suicide
What color should a commutator be? - ANS-Chocolate brown
ANS-Generator: What transforms mechanical energy into electrical energy What is saturation?
- ANS-When no more magnetic lines can be produced.
415 pg 6
What is synchronous speed? - ANS-The rotational speed of the stators magnetic field on an
Induction motor.
What is the % of slip of a 60Hz 4 pole motor that rosters at 1745rpm? - ANS-3.05%
Sync rpm- rotor rpm x100
Divided by sync rpm
What is the action in the elementary DC generator of converting AC to DC called? -
ANS-Commutation
What is the field protective relay in series with? - ANS-Safety circuit
What is the purpose of interpoles? - ANS-They prevent neutral plane shift
