Power Distribution Flashcards
- What type of cable is used for casualty power cables
THOF-42
- What part of the circuit breaker senses the overload and causes it to trip
Trip element
- What type of cable is used for shore ties?
THOF-400
- What are the max amps that #14 AWG can carry?
15
- What is tip gap?
Minimum distance between the tips of the contacts when fully open
- What does the last digit mean for a fluorescent light bulb number?
1/8” diameter
- Why should the primary of a PT always be opened before the secondary?
To prevent high current buildup
- Never replaced a type C fuse with what other type of fuse?
Type A or B
- What type of overload can you reset as soon as it trips?
Electronic
- Loud humming or chattering on a relay will warn of what condition?
Rust on sealing surfaces
- The wipe is a measure of the armature movement from the instant the contacts tips touch until the contacts are?
Completely closed
- When disposing of fluorescent lamps, what should you never do?
break them
When replacing lamps in a group, what should you do?
Replace them all
- Why should shore tie cables be the same length?
To avoid voltage unbalance between cables
- What type of switches do you need to operate a light from three places?
One 4way and two 3 ways
- Contacts with over ___ % of pitting should be replaced?
50
Why must the secondary of a current transformer be short circuited before you disconnect a current meter?
To prevent high voltage buildup on the primary and overheat
- What is the reason for using ungrounded power systems?
Improve the reliability of power to all power using equipment’s and systems. A secondary reason is to prevent galvanic corrosion of the hull caused by current flowing through either welded joints or joints of dissimilar metals.
- The trip setting for a thermal overload can be changed by?
Moving the heater element
