Power Distribution / General Electrical / Power Tools Flashcards
What do you use to discharge a capacitor?
A shorting probe across the terminals of the capacitor or the built in grounding bar.
What is the length rule for extension cords?
Only allowed to connect 2 25’ long cord and 1 100’ cord is permissible.
When working on electrical equipment you must have __________________ qualified person observing.
CPR
Primary power distribution voltage, phase and frequency is?
450V, 3 phase, 60 Hertz
Max voltage for a ship’s main switchboard should never exceed _________ volts?
462 volts
Shore power cables are rated for _______ amps?
400
Indicator RED lamp means?
Danger or emergency
Indicator GREEN lamp means?
Normal condition
Indicator WHITE lamp means?
Power available
Indicator BLUE lamp means?
Closed/Advisory
Indicator CLEAR lamp means?
Synchronizing or Ground detection
Indicator YELLOW lamp means?
Abnormal, but not requiring immediate attention.
What is a bus tie used for?
Used to connect or disconnect one bus, such as that in a switchboard, to another bus.
How do you minimize the loss resulting from eddy currents in a transformer?
Laminate the windings
What system are ACB breakers used on?
Ships service and emergency generators to the power distribution system, bus ties, shore connection circuits.
What is an NLB breaker essentially?
An off/on switch
They have no automatic tripping device
What does “trip free” mean?
A breaker that will remain open, even if the mechanism is held in the closed position.
Grounds can’t be detected through what?
A transformer
Power factor of 100% means the circuit is purely ________?
Resistive
UPS prevent ___________ outs.
Brown
A ___________ is a device without moving parts that transfers energy from one circuit to another by electromagnetic induction.
Transformer
Permanent magnet movement is known as the ___________ movement.
D’Arsonval
Shore power cable can be spliced, true of false?
True
The distance between cable supports should not exceed how many inches?
32”