P & D 1 Flashcards
How many diesel generators are fitted to a Generic Distribution Centre?
Type 45 - 2 diesel generators and 2 gas turbines generators.
Type 23 - 4 diesel generators.
What does EDC stand for?
Electrical Distribustion Centre
How many EDC’s are fitted to a Generic Distribution System?
2 EDC’s per system
What does MCCB stand for?
Moulded Case Circuit Breaker
List the 5 main breakers fitted to the Generic Distribution System and explain their use.
•Supply Breaker
•Bus Bar Linking Breaker
•Interconecting Breaker
•Feeder Breaker
•Shore Supply Breaker
What is the Power Book and when is it used?
The Power Book has diagrams of all the 450v circuits and is used when doing work on those circuits to know where/ how to isolate them correctly and show what they control.
What is the Lighting Book and when is it used?
The Lighting Book contains diagrams of the 115v and the lighting circuits and is used when working on those circuits to know the isolation points and to trace them correctly.
What is the ‘Reference Book’ and when is it used?
The ‘Reference Book’ has all the part numbers in and is used to find the codes to get parts for the circuits
What does E06 - 04 TX tell you?
Another EDC in echo EDC, 6TH fuse slot, with a transformer coming from that EDC’s 4th fuse slot.
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
The breaker nearest the fault will break first, and the supply will be the last to break
What do PCP and SCP stand for?
• Primary Control Position
• Seconday Control Position
List the meters fitted to a switchboard generator section.
•Voltmeter
•Frequency meter
•Watt meter
•Ammeter
•Syncroscope
•Earth fault indicator
What are the breaker opening switches, and where are they found?
In the EDP, you’ll find:
•Start/Stop Switch
•Selector Switch
•Discrepancy Switch
•Control Switch
What does MCR stand for?
Machinery Control Room
Describe the connection of shore supply.
•Send signal to port.
•Raise permit to work.
•Rack out breakers.
•Test for dead.
•Obtain castel key.
•Test shore supply cables.
•Bring on and secure cables.
•Connect cables.
•Inform dockyard so that they can turn on the power.
What are the rules regarding earthing the ship when connecting shore supply?
•Ship must be earthed when taking on the flexible cables for either shore supply or to supply another ship.
•Earth bonding must be at 2 points that are not less than half the ships length apart.
•When alongside the gangways, must also be earthed.
What is used confirmed correct phase rotation with respect to shore supply?
There are 2 indication lights, and it’ll the right one is brighter than the left, then you have the correct phase rotation.
What would happen to a motor if phase rotation is wrong?
The motor would turn the wrong way and damage the connecting parts.
List 3 types of hand changeover switches.
•Normal/ Alternative Changeover Switch.
•Normal/ Emergency Changeover Switch.
•Normal/ Alternative/ Energency Changeover Switch.
List 3 kinds of changeover switches.
•Hand Changeover Switch (HCOS)
•Automatic Changeover Switch (ACOS)
•Remote Operated Changeover Switch (ROCOS)
What and where are the 440v earth testing facilities found?
In the PCP and the SCP you’ll find indicator lights and an alarm that alerts you to an earth fault in the circuit.
Why are there separate 115v testing facilities?
Transformer in the cicuit that causes there to be an earth gap that isn’t recognised by the earth testing facilities used in the 440v circuit.
