General Systems Flashcards
How many diesel generators are fitted to a general system?
4
What does EDC stand for
Electrical distribution centre
How many EDC does a general distribution system have
As many as required
What does MCCB stand for
Moulded case circuit breaker
5 main breakers in a general distribution system
Supply breaker
Feeder breaker
Bus bar linking breaker
Interconnecting breaker
Shore supply breaker
What is a supply breaker
Goes from a supply to a bus bar
What is a feeder breaker
Goes from a bus bar to kit/equipment
What is the power book
Shows the distribution of all 450v services
What is the lighting book
Shows all distribution of 115v lighting
What is the reference book
Shows all part numbers and quantities
440v discrimination ratio
3:1
115v discrimination ratio
2:1
What is breaker discrimination
When the closest breaker to the fault is the first to trip
What does MCR stand for
Machine control room
What are PCP and SCP
Primary control position
Secondary control position
What meters are fitted to a switchboard (5)
Volt meter
Ammeter
Frequency meter
Watt meter
Syncroscope
What are the breaker operating stitches on the switchboard called (4)
Discrepancy switch
Start/stop switch
Selector switch
Control switch
What is the process of connecting a shore supply
- Send a signal 24 hours before
- Raise permit to work
- Rack out breakers
- Test for dead
- Get the castel key
- Test shore supply cables
- Bring on and secure cable
- Connect cables
- Infirm dockyard
Where is a ship earthed
Gangway
No less then half the ships length
What is used to confirm correct phasing
The light on the right is bright
What would happen to a motor if phasing was incorrect
The motor would spin backwards
3 hand change over switches
Normal/Alternative
Normal/Emergency
Normal/Alternative/Emergency
3 kinds of change over switch
Automatic change over switch (ACOS)
Remote change over switch (RCOS)
Hand change over switch (HCOS)
What and where are the 440v earth testing facilities found
Control positions
Lamp and audible alarm
Why is there a separate 115v test
Because of the transformer there is no physical connection