Reading...
Play button
Play button
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;
17 Cards in this Set
- Front
- Back
|
On an FFG 7 class ship where are the APU's located?
|
2 APU's on each side of the keel between frames 100 - 108.
|
|
|
What are the 3 major components of an APU?
|
APU motor
training and retracting device (TRD) controls |
|
|
T or F, does an APU have a kort nozzle?
|
True
|
|
|
What does the TRD consists of?
|
Support column
2 motors - 1 for rotating the unit and 1 for retracting the motor |
|
|
What 2 types of problems that genrally occur in the APU system?
|
electrical and mechanical
|
|
|
what are the typical electrical problems?
|
grounding of one or more phases of the 3 phase, 440 VAC system
|
|
|
What should be used by ships force to megger each phase of an APU elec. system?
|
500-VDC megger
|
|
|
What is used to correct each electrical insulation resistance measurement?
|
Nomograph to the equivalent 25 degrees celseus
|
|
|
The corrected insulation resistance must be equal to or greater than ____ megohms, and what should be achievable?
|
3 megohms and 10 megohms should be achievable
|
|
|
What are signs of mechanical damage or bearing wear problems?
|
High motor amperage (> 800 amperes) or an increase in noise or vibration during APU motor operation
|
|
|
What kind of inspection must be conducted on an APU in both the retracted and the deployed position and what position do you start the inspection in?
|
level 2 inspection with the unit in the deployed position.
|
|
|
What must ships force do after retracting the APU 6" below the hull opening?
|
Verify that the bench mark is at the "zero" position.
|
|
|
What is the allowable gap between the hull opening and the fairing plate?
|
1" +/- 1/4" Uniform gap all the around
|
|
|
What must be done if the total fore and aft movement of the prop. shaft is more than 1/8 (0.125) inch?
|
APU motor thrust bearing must be replaced
|
|
|
What must be done if any propeller tip-to-kort nozzle clearance is less than 0.040 inch or more than 0.185 inch?
|
APU motor sleeve bearing must be replaced
|
|
|
How should the ship be moored and what is the minimum water depth below the keel required so work can be conducted on the APU?
|
damaged APU towards the pier
minimum of 10 feet below the keel, with 20 feet desirable |
|
|
For planning purposes how many 8 hour shifts should it take to complete a waterborne APU motor replacement?
|
4 days
5 days - 1 additional day if electrical cable removal and replacement is required |
