Power and Distribution Flashcards
What are the 3 basic items needed for power generation?
-prime mover
-a generator
-switchboard
What goes EDC stand for?
Electrical distribution centre
What does MCCBs stand for ?
Moulded case circuit breakers
What does a supply breaker do?
Connect generator output to the switchboard
What does a shore supply breaker do?
Connects shore supply or supply from another shop to the switchboard and convents the ships supply to another ship
What does a bus bar linking breaker do?
Connects two bus bars of the same voltage in a switchboard together
What does an interconnection r breaker do?
Connects 2 switchboards together
What does the power book show?
the distribution of all 440V services
What does the lighting book show?
115V/230V systems
What does the portable appliance book show?
Power supplies with 115/230V sockets
What does the reference to fittings book show?
-store numbers
-types of fittings
-number of fittings
What are the 7 main components to the power and distribution system?
- generator
-supply breaker
-switchboard section
-feeder breaker - fuse panel
-transformers
-distribution panels
What is the first breaker to trip?
MCCB
Closest breaker to the fault
What is the last breaker to trip?
Supply breaker
Furthest away from the fault
What ratio does 440V discrimination use?
3:1
What does 115V discrimination use?
2:1
what’s does PCP stand for and where is it operated?
Primary control position
SCC
what does SCP stand for and where is it located?
Secondary control position
Switchboard sections
What are the 6 meters that provide information about power supplied by shore supply?
-voltmeter
-frequency meter
-watt meter
-ammeter
-syncroscpe
-Earth fault indicator
What actions are required for connecting to shore supply?
-send signal to port
-raise a permit to work
How to remember which light should be bright to ensure a good connection to shore supply?
Right is bright, everything is alright
Where are the earth cables fitted when connect to shore supply?
-to the jetty
-to the ship along side
-gangway
-at two points not less than half the ships length apart
What are the types of hand changeover switches?
-normal/alternative
-normal/emergency
-normal/alternative/emergency
what are the categories of changeover switches?
-automatic changeover switch
-remote operated changeover switch
-hand changeover switches
What does C&C stand for ?
Control and communication switchboard
what is a converted supply?
A supply that has its voltage and/or frequency changed from 450V/60Hz before it is distributed around the ship
What are the two converted supplies, supplied by the C&C switchboard?
24V DC
115V, 400Hz
What does TRU stand for?
Transformer rectifier unit
What does RTR stand for ?
Rationalised transformer rectifier
What are the earth testing arrangements on C&C switchboards?
Integral light
What is a battery?
Number of cells connected in series
what are the two categories of batteries?
primary
secondary