P & D 1

Question 1

How many diesel generators are fitted to a Generic Distribution Centre?

Answer 1

Type 45 - 2 diesel generators and 2 gas turbines generators.
Type 23 - 4 diesel generators.

Question 2

What does EDC stand for?

Answer 2

Electrical Distribustion Centre

Question 3

How many EDC’s are fitted to a Generic Distribution System?

Answer 3

2 EDC’s per system

Question 4

What does MCCB stand for?

Answer 4

Moulded Case Circuit Breaker

Question 5

List the 5 main breakers fitted to the Generic Distribution System and explain their use.

Answer 5

•Supply Breaker
•Bus Bar Linking Breaker
•Interconecting Breaker
•Feeder Breaker
•Shore Supply Breaker

Question 6

What is the Power Book and when is it used?

Answer 6

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.

Question 7

What is the Lighting Book and when is it used?

Answer 7

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.

Question 8

What is the ‘Reference Book’ and when is it used?

Answer 8

The ‘Reference Book’ has all the part numbers in and is used to find the codes to get parts for the circuits

Question 9

What does E06 - 04 TX tell you?

Answer 9

Another EDC in echo EDC, 6TH fuse slot, with a transformer coming from that EDC’s 4th fuse slot.

Question 10

What is the ratio for 440v fuses regarding fuse discrimination?

Answer 10

3:1

Question 11

What is the ratio for 115v fuses regarding fuse discrimination?

Answer 11

2:1

Question 12

Explain Breaker discrimination

Answer 12

The breaker nearest the fault will break first, and the supply will be the last to break

Question 13

What do PCP and SCP stand for?

Answer 13

• Primary Control Position
• Seconday Control Position

Question 14

List the meters fitted to a switchboard generator section.

Answer 14

•Voltmeter
•Frequency meter
•Watt meter
•Ammeter
•Syncroscope
•Earth fault indicator

Question 15

What are the breaker opening switches, and where are they found?

Answer 15

In the EDP, you’ll find:
•Start/Stop Switch
•Selector Switch
•Discrepancy Switch
•Control Switch

Question 16

What does MCR stand for?

Answer 16

Machinery Control Room

Question 17

Describe the connection of shore supply.

Answer 17

•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.

Question 18

What are the rules regarding earthing the ship when connecting shore supply?

Answer 18

•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.

Question 19

What is used confirmed correct phase rotation with respect to shore supply?

Answer 19

There are 2 indication lights, and it’ll the right one is brighter than the left, then you have the correct phase rotation.

Question 20

What would happen to a motor if phase rotation is wrong?

Answer 20

The motor would turn the wrong way and damage the connecting parts.

Question 21

List 3 types of hand changeover switches.

Answer 21

•Normal/ Alternative Changeover Switch.
•Normal/ Emergency Changeover Switch.
•Normal/ Alternative/ Energency Changeover Switch.

Question 22

List 3 kinds of changeover switches.

Answer 22

•Hand Changeover Switch (HCOS)
•Automatic Changeover Switch (ACOS)
•Remote Operated Changeover Switch (ROCOS)

Question 23

What and where are the 440v earth testing facilities found?

Answer 23

In the PCP and the SCP you’ll find indicator lights and an alarm that alerts you to an earth fault in the circuit.

Question 24

Why are there separate 115v testing facilities?

Answer 24

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.