ADOC JOSMRC Part 1
What are the six core principles of Sound Shipboard Operating Principles? -
ANS-Formality;
Forceful backup;
Procedural compliance;
Integrity;
Questioning attitude;
Level of knowledge
voltage - ANS-electromotive force/potential difference [V]
current - ANS-the flow of electrons, by-products are heat and magnetic field [I/A]
resistance - ANS-electrical quantity that measures how the device/material reduces the
electric current flow through it [R ohms]
Ohm's Law - ANS-law relating the voltage difference b/w 2 points,
the electric current flowing b/w them, and the resistance of the path of the current
V=IR
Open Circuit - ANS-infinite resistance, zero current
short circuit - ANS-minimum resistance, max current
power - ANS-rate at which electrical energy is transferred by a circuit; rate at which
work is being done (watts, HP, joules per sec) [P]
Types of AC Power - ANS-True: dissipated by load (W)
Reactive: power absorbed & returned in load
Apparent: derivation of true & reactive
Power Factor - ANS-Ratio of real power flowing to load to apparent power in circuit; ID
power lost (heat, magnetic field); standard is 0.8 pf or 80%
Direct Current - ANS-unidirectional flow of electric charge [DC]
Alternating Current - ANS-electric current in which flow of electric charge periodically
reverses direction [AC]
,Frequency - ANS-# of cycles per sec [Hz]
Polarity - ANS-direction of current flow in electrical circuit, from positive to negative
(electrons flow from negative to positive)
Conductors - ANS-substance in which electrical charge carriers, usually electrons,
move easily from atom to atom with the application of voltage (silver, gold, copper)
Insulator - ANS-Having extremely high resistance to the flow of charge through them
(wood, fiberglass, plastic, rubber)
Capacitance - ANS-device to store electric charge; one or more pairs of conductors
separated by an insulator [C]
Capacitor Safety - ANS-use shorting probe, discharge capacitors before work on equip
Inductance - ANS-passive 2 terminal electrical component which resists changes in
electric current passing through it; Energy is stored in a magnetic field around the coil
as long as current flows [L]
Requirements for AC EM induction
"Momma's Fried Chicken" - ANS-Motion (Rel)
Field (mag)
Conductor
prime mover - ANS-engine that converts fuel to useful work
Parts of a Generator (4) - ANS-Internal;
Permanent Magnetic Alternator; Governor;
Voltage Regulator
Internal parts of a generator - ANS-Stator;
rotor;
Poles;
Armature;
Field Windings
stator - ANS-Stationary element;
Conductor of MFC;
, Houses Armature Windings
rotor - ANS-Rotating element;
Receives excitation voltage from the rotating rectifier assembly;
Provides main magnetic field for the generator;
Consists of Field Windings
poles - ANS-Most Naval Generators have 4 poles (2 N, 2 S)
armature - ANS-Moving conductor of MFC;
Current carrying piece
field windings - ANS-Produces magnetic field in a motor/generator
Permanent Magnetic Alternator - ANS-120 VAC excitation power to voltage regulator
during initial start-up; once the main generator field voltage reaches 340 VAC, the VR
will switch excitation power over to the main generator field
Governor - ANS-convert electrical signal to mechanical motion, to control amount of fuel
injected to engine
Voltage Regulator - ANS-maintains 450 VAC generated; adjusts DC voltage on rotor
Transformer theory - ANS-Transfers AC Power from one circuit to another by EM
Induction;
FREQUENCY is not changed;
No Moving Parts;
"Step-Up" or "Step-Down";
Determined by "Turns ratio" of primary and secondary windings
selective tripping - ANS-Provides for removal from the system of a faulted part only,
leaving the rest of the
system in operation;
Ensures protective device closest to fault trips
selected tripping - ANS-Manual tripping of a breaker or switch;
Turing on/off light switches;
Turning on/off equipment; T/S, Ground Isolation procedure used to isolate faulted
component
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 denicetho. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $9.31. You're not tied to anything after your purchase.