Pn D Flashcards
How many diesel generators are fitted to a generic distribution system
4 generator fitted to ship
What does EDC stand for
Electrical distribution centre
How many EDC’s are fitted to a generic distribution system
4 EDC’s
What does MCCB stand for
Moulded case circuit breaker
List 5 breakers fitted to a generic distribution system
Supply breaker Shore breaker Interconnecting breaker Bus bar linking breaker Feeder breaker
What is power book and where is it used
Power Book shoes distribution of all 440V services used when tracing which services are fed from which fuse panel, transformer l, MCCB and EDC
What is the reference book
The power book lists all the fittings, number fitted, component symbols and pattern numbers
What is the ratio of 440 V 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 would trip first.
supply breaker being furthest from the fault would trip last.
What does MCR stand for
Machinery control room
What does PCP, SCP
Primary control position
Secondary control position
List the meters fitted to a switch board generator section
Volt meter Amp meter Earth fault indicator Syncroscope Frequency meter KW meter
Where are the breaker operating switches found and what are they called
Discrepancy switches located in PCP
Describe the connection shore supply
A permit to work from is raised prior to arrival
The shore supply’s breakers are to be racked out
The shore supply box is cover is removed and connection check for dead
A castle key is obtained from dockyard
Continuity, non contact and insulation resistance tests are carried out on shore supply cables
Shore supply cables are brought onto the ship and secured
Cables are connected to shore supply box
Inform the dockyard who will then switch on the power and ensure correct phase connection
What are the rules regarding to earthing the ship when connection shore supply
Ship must always be earthed to the jetty or by the ships alongside by two points. No less than half the ships length apart, plus gangeay
What is used to confirm correct phase rotation with respect to shore supply
A phase sequence indicator the right one should be brighter
What would happen to a motor if phase rotation is wrong
Motors would run backwards
List 3 types handover switches
Normal/alternative
Normal/emergency
Normal/alternative/emergency
List 3 types of switches
Hand change over switch
Remote change over switch
Automatic change over switch
What and where are the 440 v earth testing facilities found
Earth indicator lights is located on switchboard
Why are the Speer are 115v testing facilities
Not physically connected to the primary winding
What does c and c stand for
Control and communication
Define what a converted supply is
A converted supply has its voltage or frequency changed from 450 v,60 hz
What are the main voltages used in the c and c switchboard
24 volts DC
115 volts,400 hertz
What and where is the earth testing facilities for 24V D.C
An earth test panel on the switchboard provides for testing the positive and negative side of the DC supply
What does TRU stand for
Transformer rectifier unit
What does RTR stand for
Rationalised transformer rectifier
Batteries fall into 2 categories what are they
Primary
Secondary
What are the characteristics of the 2 batteries
Primary not rechargeable
Secondary- rechargeable
What are the capacity of a battery measured in
Batteries are measured in amps per hour
What is the voltage of a fully charged cell
2.1 fully charged
What is the voltage of a discharged cell
1.75 v discharged
How many diesel generators are fitted to type 23
There are 4 diesel generators fitted to a type 23
What is the output of the generators fitted to a type 23
The output is 600V,61.2Hz,3 phase,1.3MW
Why do we produce such a voltage
450V system would not have given a large enough range of speeds when using the electrical propulsion system
What are the breakers fitted to a type 23 p and d system
Supply breakers Inter connector breaker Shore supply breaker Electric motor breaker Motor generator feeder breaker Diesel generator alternative supply breaker
What does the converter regulated do
Convert regulator converts and regulates the voltage at 750VDC
What is the voltage required for the ships services and how is it produces
450 v required for ships services in s generated by motor generator
What are EDPS and how many types are fitted
Three types of EDP’s are fitted to a type 23
What are shedable services and why do we have them
Provide power to non-essential equipment and allow, more power to the propulsion’s motor
What would happen if we were to loose both motor generators and how is this achieved
The 600V generator can be re-configurated to supply 450V to the 450v system via a 4 position witch to the rear of the switchboard
What services does the emergency switchboard supply
Steering motors Hp salt water pump Sugary Smoke clearance exhaust fans Portable pump sockets
What are EMACB
Electrical motor air circuit breaker, supplies 600 V to the electric propulsion motor
Why is the electric propulsion preferred when involved in submarine warfare
To reduce noise, reducing the range and which our ships can be detected and our own interference with towed array sonar operation
What SRPM and knots do 2 diesel generators produced
2 generation= 65 SRPM
=8-9knots
What SRPM and knots do 3 diesel generators produce
3 generators= 80 SRPM=10-12 knots
What SRPM and knots do 4 diesel generators produce
4 generators= 90 SRPM=14 knots
In the event of action damage to the SCC, how can the propulsion motors be controlled
Propulsion motors can be controlled from the local control panels
What and where are the 440V earth testing facilities found
Earth indicator light is located on switchboard
Why are there delegate 115v testing facilities
Not physically connected to the primary welding
When are the navigation lights tested and by who
Lights are testing daily hour before sunset, normally by the duty ETME
Whose permission must be gained
Permission to switch lights on must be obtained from the OOW/OOD
Where are navigation lights controlled from and switched on and off
Navigation light control panel, versatile console system
List all statutory navigation lights, their colour and location
Side lights green and red are starboard and port
The last head steaming light forwards and af(white)
Stern light(white)
List all combination of special operation lights
Not under command —2 steady lights port 2 steady lights starboard
Replenishment at sea—2 steady lights port and starboard
M.O.B—2 flashing red lights port and 2 starboard vertically mounted on the main mast
Where are special operation lights switched from
VCS 428 unit
List all miscellaneous light anchor lights
Anchor lights
Masthead obstruction lights
How are the emergency navigation lights fed
Emergency navigation lights are fixed in position adjacent to their normal counter parts and are supplied via fixed wiring by two series connected 12 volt batteries
Why is it important to switch on the emergency navigation before being hoisted
If they are hoisted then plugged in an induced current may be present due to radar and radio aerial interference
List 4 main components of a fluorescent light fitting
Stater
Tube
Switch supply
Choke coil
