revision

Question 1

what is the power book and when is it used?

Answer 1

it shows the distribution of all 440v services used when tracing which services are fed from which fuse panel.

Question 2

what is the lighting book and when is it used?

Answer 2

shows the 115v / 230v and is used the same way as the power book

Question 3

what is the reference book and when is it used ?

Answer 3

used in conjunction with the power book and lists all fittings, number fitted, component symbols and pattern numbers

Question 4

explain breaker discrimination

Answer 4

it would be impossible for a fault on a mess deck kettle to trip a main generator .

Question 5

what does MCR stand for ?

Answer 5

machinery control room

Question 6

list the meters fitted to a switchboard generator section

Answer 6

voltmeter
ammeter
kw meter
frequency meter
syncroscope
earth fault indicator

Question 7

where are the breaker operating switches found and what are they called ?

Answer 7

start / stop, selector, control and discrepancy switches located in the pcp

Question 8

what are the rules regarding to earthing the ship when connecting shore supply ?

Answer 8

the ship must be earthier either to the jetty or to the ship alongside by at least two points no less than half the ships length apart

Question 9

what is used to confirm correct phase rotation with respect to shore supply ?

Answer 9

the phase sequence indicator (2 lamps) the right one should be brighter

Question 10

what would happen to the motor if the phase rotation is wrong ?

Answer 10

motors would run backwards

Question 11

list 3 types of hand change over switches

Answer 11

normal / alternative
normal / emergency
normal / alternative /emergency

Question 12

list 3 types of change over switches

Answer 12

hand change over switch
automatic change over switch
remote operated change over switch

Question 13

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

Answer 13

earth indicator light located on the switchboard, some also have audible alarms

Question 14

why are there separate 115v testing facilities ?

Answer 14

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

Question 15

what does CandC stand for ?

Answer 15

control and communications (switchboard)

Question 16

define what a converted supply is ?

Answer 16

a converted supply has its voltage and or frequency changed from 450v, 60Hz

Question 17

what are the voltages used in the CandC switchboard ?

Answer 17

24 volts DC
115 volts 400 Hertz

Question 18

what and where is the earth testing facilities for 24v DC ?

Answer 18

an earth test panel on the switchboard provides for testing the positive and negative side of the DC supply. A push button with integral lamp is fitted to the switchboard

Question 19

what does RTR stand for?

Answer 19

rationalised transformer rectifier

Question 20

what does TRU stand for ?

Answer 20

transformer rectifier unit

Question 21

what two categories do batteries fall into?

Answer 21

primary and secondary

Question 22

what are the characteristics of the two batteries ?

Answer 22

primary - dry , not rechargeable , usually small

secondary - wet , rechargeable, small to large

Question 23

what is the capacity of a battery measured in ?

Answer 23

amp-hour (Ah)

Question 24

what is the voltage of a fully charged cell ?

Answer 24

2.1v

Question 25

what is the voltage of a discharged cell ?

Answer 25

1.75v

Question 26

what is the output of the generators fitted to a type 23?

Answer 26

600v, 61.2Hz, 3 phase

Question 27

what does the converter regulator do ?

Answer 27

converts and regulates the voltage at 750v DC

Question 28

what are EDPs and how many are fitted?

Answer 28

three types of electrical distribution panels are fitted to type 23s

Question 29

what are shedable services and why do we have them?

Answer 29

shedable EDPs provide power supplies to non-essential equipment

Question 30

what would happen if we were to lose both motor generators and how is this achieved ?

Answer 30

the 600v generator can be re configured to supply 450v to the 450v system via a 4 position switch at the rear of the switchboard

Question 31

when are the navigation lights tested and by who ?

Answer 31

lights are to be tested daily one hour before sunset, normally by the duty ETME

Question 32

whose permission must be gained first before testing navigation lights ?

Answer 32

permission must be gained by the
OOW/ OOD

Question 33

where are navigation lights controlled from and switched on and off ?

Answer 33

the navigation lights control panel, located on the bridge

Question 34

list all statutory nav lights and their colours and location

Answer 34

side lights- port (red) starboard (green)
the mast head steaming light- forward and aft (white) and stern light (white)

Question 35

where are special operation light switched on from ?

Answer 35

these are operated by the VCS 428 unit

Question 36

list all miscellaneous lights, their colours and location

Answer 36

anchor lights- on top of the fwd and aft jackstaffs and white i colour

masthead obstruction lights- red in colour and mounted port and starboard at the top of the mainmast

Question 37

how are the emergency navigation lights fed ?

Answer 37

they are fixed in position adjacent to their normal counter parts and are supplied via fixed wiring by two series-connected 12 volt batteries

Question 38

why is it important to switch on the emergency NUC/RAS lights before being hoisted ?

Answer 38

if they are hoisted then plugged in and induced current may be present due to radar and radio aerial interference

Question 39

list the four main components of a fluorescent light fitting

Answer 39

starter
tube
choke coil
switched supply