P And D 1

Question 1

How many diesel generators are fitted to a generic distribution system

Answer 1

4

Question 2

What does EDC stand for

Answer 2

Electrical Distribution Centre

Question 3

How many EDC’s are fitted to a generic distribution system

Answer 3

4

Question 4

What does MCCB stand for

Answer 4

Moulded case circuit breakers

Question 5

List the 5 main breakers fitted to a generic distribution system

Answer 5

Supply breaker 
Bus bar linking breaker 
Interconnecting breaker 
Feeder breaker 
Shore supply breaker

Question 6

What is the power book and when is it used

Answer 6

Shows the distribution of all 440V services used when tracing which services are fed from which fuse panels, transformer, MCCB and EDC

Question 7

What is the lighting book and when is it used

Answer 7

The lighting book shows 115V / 230V and is used when tracing which services are fed from which fuse panel, transformer, MCCB and EDC

Question 8

What is the reference book and when is it used

Answer 8

The reference book is used in conjunction with the Power Book and lists all fittings, number fitted, component symbols and pattern numbers

Question 9

What is the ratio for 440V fuses regarding fuse discrimination

Answer 9

3:1

Question 10

What is the ratio for 115V fuses regarding fuse discrimination

Answer 10

2:1

Question 11

Explain breaker discrimination

Answer 11

With breaker and fuse discrimination, it would be impossible for a fault on a mess deck kettle to trip a main generator

Question 12

What does MCR stand for

Answer 12

Machinery Control Room, if combined with HQ1 it would be known as Ships Control Centre

Question 13

What does PCP and SCP stand for

Answer 13

Primary Control Position, Secondary Control Position

Question 14

List the meters fitted to a switchboard generator section

Answer 14

Voltmeter
Ammeter
KW Meter
Frequency Meter
Syncroscope
Earth Fault Indicator

Question 15

Where are the breaker operating switches found and what are they called

Answer 15

Start/Stop, selector, control and discrepancy switches located in the PCP

Question 16

Describe the connection of shore supply

Answer 16

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

Question 17

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

Answer 17

Has to be earthed at two points at nothing less than half the ships length away.
Gangways are also to be earthed

Question 18

What is used to ensure correct phase rotation with respect to shore supply

Answer 18

Check voltage and frequency
Check for stability of supply
Check proper connection of cables

Question 19

What would happen to a motor if phase rotation is wrong

Answer 19

Motors would run backwards

Question 20

List 3 types of hand changeover switches

Answer 20

Normal/alternative
Normal/emergency
Normal/alternative/emergency

Question 21

List 3 types of changeover switches

Answer 21

Hand Change Over Switch (HCOS)
Automatic Change Over Switch (ACOS)
Remote Operated Change Over Switch (ROCOS)

Question 22

What and where are the 440V earth testing facilities found

Answer 22

Earth indicator light on the switchboard, and sometimes an audible alarm

Question 23

Why are there separate 115V testing facilities

Answer 23

115V is a transformed supply and the secondary winding is not physically connected to the primary winding