P And D 1 Flashcards
How many diesel generators are fitted to a generic distribution system
4
What does EDC stand for
Electrical Distribution Centre
How many EDC’s are fitted to a generic distribution system
4
What does MCCB stand for
Moulded case circuit breakers
List the 5 main breakers fitted to a generic distribution system
Supply breaker Bus bar linking breaker Interconnecting breaker Feeder breaker Shore supply breaker
What is the power book and when is it used
Shows the distribution of all 440V services used when tracing which services are fed from which fuse panels, transformer, MCCB and EDC
What is the lighting book and when is it used
The lighting book shows 115V / 230V and is used when tracing which services are fed from which fuse panel, transformer, MCCB and EDC
What is the reference book and when is it used
The reference book is used in conjunction with the Power Book and lists all fittings, number fitted, component symbols and pattern numbers
What is the ratio for 440V fuses regarding fuse discrimination
3:1
What is the ratio for 115V fuses regarding fuse discrimination
2:1
Explain breaker discrimination
With breaker and fuse discrimination, it would be impossible for a fault on a mess deck kettle to trip a main generator
What does MCR stand for
Machinery Control Room, if combined with HQ1 it would be known as Ships Control Centre
What does PCP and SCP stand for
Primary Control Position, Secondary Control Position
List the meters fitted to a switchboard generator section
Voltmeter Ammeter KW Meter Frequency Meter Syncroscope Earth Fault Indicator
Where are the breaker operating switches found and what are they called
Start/Stop, selector, control and discrepancy switches located in the PCP
Describe the connection of shore supply
Send signal to work (24 hours in advance)
Raise permit to work (prior arrival)
Rack out shore supply breakers
Prove box is ‘dead’
A castel key is obtained from a dockyard
Test shore supply cables (making sure there’s enough slack for change of tides
Connect cables to shore supply box ensuring correct phase connection
Inform the dockyard who will then turn on the power
What are the rules regarding to earthing the ship when connecting shore supply
Has to be earthed at two points at nothing less than half the ships length away.
Gangways are also to be earthed
What is used to ensure correct phase rotation with respect to shore supply
Check voltage and frequency
Check for stability of supply
Check proper connection of cables
What would happen to a motor if phase rotation is wrong
Motors would run backwards
List 3 types of hand changeover switches
Normal/alternative
Normal/emergency
Normal/alternative/emergency
List 3 types of changeover switches
Hand Change Over Switch (HCOS)
Automatic Change Over Switch (ACOS)
Remote Operated Change Over Switch (ROCOS)
What and where are the 440V earth testing facilities found
Earth indicator light on the switchboard, and sometimes an audible alarm
Why are there separate 115V testing facilities
115V is a transformed supply and the secondary winding is not physically connected to the primary winding
