Power and Distribution Flashcards
What are the 3 basic items needed for power generation?
-prime mover
-a generator
-switchboard
What goes EDC stand for?
Electrical distribution centre
What does MCCBs stand for ?
Moulded case circuit breakers
What does a supply breaker do?
Connect generator output to the switchboard
What does a shore supply breaker do?
Connects shore supply or supply from another shop to the switchboard and convents the ships supply to another ship
What does a bus bar linking breaker do?
Connects two bus bars of the same voltage in a switchboard together
What does an interconnection r breaker do?
Connects 2 switchboards together
What does the power book show?
the distribution of all 440V services
What does the lighting book show?
115V/230V systems
What does the portable appliance book show?
Power supplies with 115/230V sockets
What does the reference to fittings book show?
-store numbers
-types of fittings
-number of fittings
What are the 7 main components to the power and distribution system?
- generator
-supply breaker
-switchboard section
-feeder breaker - fuse panel
-transformers
-distribution panels
What is the first breaker to trip?
MCCB
Closest breaker to the fault
What is the last breaker to trip?
Supply breaker
Furthest away from the fault
What ratio does 440V discrimination use?
3:1
What does 115V discrimination use?
2:1
what’s does PCP stand for and where is it operated?
Primary control position
SCC
what does SCP stand for and where is it located?
Secondary control position
Switchboard sections
What are the 6 meters that provide information about power supplied by shore supply?
-voltmeter
-frequency meter
-watt meter
-ammeter
-syncroscpe
-Earth fault indicator
What actions are required for connecting to shore supply?
-send signal to port
-raise a permit to work
How to remember which light should be bright to ensure a good connection to shore supply?
Right is bright, everything is alright
Where are the earth cables fitted when connect to shore supply?
-to the jetty
-to the ship along side
-gangway
-at two points not less than half the ships length apart
What are the types of hand changeover switches?
-normal/alternative
-normal/emergency
-normal/alternative/emergency
what are the categories of changeover switches?
-automatic changeover switch
-remote operated changeover switch
-hand changeover switches
What does C&C stand for ?
Control and communication switchboard
what is a converted supply?
A supply that has its voltage and/or frequency changed from 450V/60Hz before it is distributed around the ship
What are the two converted supplies, supplied by the C&C switchboard?
24V DC
115V, 400Hz
What does TRU stand for?
Transformer rectifier unit
What does RTR stand for ?
Rationalised transformer rectifier
What are the earth testing arrangements on C&C switchboards?
Integral light
What is a battery?
Number of cells connected in series
what are the two categories of batteries?
primary
secondary
What are the 4 main characteristics of primary batteries/cells?
-not rechargeable
-known as dry cells
-once discharged they are thrown away
-normally small
what are the 4 main characteristics of secondary batteries/cells?
- rechargeable
-wet cells
-requires specialist recharging equipment
-variety of sizes
what is the capacity of a battery measured in?
Amp-hour (Ah)
What is voltage of fully charged cell?
2.1V
what is the voltage of fully discharged cell?
1.75V
What is the output of AC generators on T23?
- 1.3 MW
- 600V
- 61.2Hz
- 3 Phase
What are the seven types of breakers used in the type 23 distribution systems?
-supply breaker
-interconnector breaker
- shore supply breaker
- electric motor breaker
- motor generation feeder breaker
-motor generator supply breaker
-diesel generator alternative supply breaker
What Voltage is used exclusively for the electric propulsion system on a T23 ?
600V
3 types of EDPs fitted to the type 23?
Type 1
Type 2
Type 3
What is a shedable EDC
Non essential equipment:
- Galley
-Laundry
-miscellaneous lighting
Can be the shedables be tripped?
Yes, to provide more power to electrical motors or reduce power consumption around the ship
What does the T23 emergency switchboard supply?
-steering motors
-HPSW pumps
-Surgery/sickbay
-smoke clearance exhaust fans
-portable pump sockets
What 8 basic components is the electric propulsion motor system composed of?
-armature
-commutator
-brush gear
-cooling fans
-air filter
-yoke
-compiles
-main poles
Describe electrical motor cooling
- Cool air is drawn through the motor
- Done by two ventilation fans
- Air is forced over the main poles, armature commutator and brush gear
- Cool air absorbs the heat generated in the motor
- it’s exhausted from the motor at the commutator end
- the air is forced through a water cooled heat exchanger into the engine
what happens if the heat exchanger fails?
- two emergency inlet panels are removed
- allows air to be drawn into the cabinet by the circulating fan
What do the gas turbine driven generators produce?
-4160V
-60 Hz
- 3 phase
- Capacity of 21 MW
What do the diesel driven generators produce?
-4160V
-60Hz
-3 Phase
-2 MW
What is a harmonic Filter?
-Used to ensure the quality requirements of the power supply
-smooth the wine waves of the voltage supply
-uses capacitors and resistors
What does IEP stand for?
Integrated Electric propulsion
(known as integrated electric drive)
What is connected to the bus bay supplied by the output of 21MW generator?
1W advanced induction propulsion motor
What does PMS stand for?
Platform management system
What does EPMS stand for?
Electrical Power Management System
When are navigation lights tested and by who?
1 hour before sunset by the duty ET(ME)
who are the times of when the navigation lights are tested obtained from?
OOD/OOW
When are navigation lights switched on?
Sunset
When are navigation lights switched off?
sunrise
What does NCLP stand for?
Navigation Lights Control Panel
What are the statutory navigation lights?
Compulsory and must be switched on at sunset on every ship
what colour are the statutory lights and where are they located?
side lights—> PORT -red, STBD—green
masthead steaming lights—> FWD and AFT- White
stern light —> deck level- white
What are the emergency statutory lights supplied by?
Two series-connected 12V batteries
What are the special operation lights operated by?
VCS 428 unit
When are special operation lights tested?
1 hour before sunset
What colour abs where are the hot under command lights?
- 2 steady red lights port and 2 steady red lights STBD
- vertically mounted on the main mast
-switched on when the ship will not answer the helm
what colour and where are the lights used for RAS?
- 2 steady red lights port and 2 steady red lights STBD
- A single white light both sides between the red lights
-vertically mounted in the mainmast - switched on when never there is a RAS
what colour are where are lights used in a man overboard situation?
- 2 red flashing lights port and 2 red flashing lights STBD
- vertically mounted on the main mast
- switched on when someone had fallen overboard
when are the emergency special operation lights tested?
1 hour before sunset
what must happen before the emergency special operation lights are hoisted up the mast and why?
- plugged in and switched k.
- if not, an induced current maybe present due to radar and aerial interference
what lights are classed as miscellaneous lights ?
- anchor lights
- mast obstruction lights
- hostable towing light
where are the anchor lights fitted and what colour are they?
fitted on the top of the FWD and AFT jackstaffs
- White
Where are the mast obstruction lights fitted and what colour are they?
Port and STBD main mast top
- red
when is weather deck lighting tested?
1 hour before sunset
What 4 components is the fluorescent light comprised of?
- starter
- Tube
- Choke coil
- Switched supply
What does the tube contain?
- interior is coated in fluorescent phosphor
- filled with low pressure argon gas
- contains a small amount of mercy
What does AEL stand for?
Automatic emergency lights
What does the rear of the T24 AEL compromise of?
- PCB retaining clip
-Base casting clip - Battery retaining clip
- Battery 2.4V
-terminal block
what does the printed circuit board (PCB) on the T23 AEL comprise of?
- battery connections
- test push switch
- pilot indicator lamp
- main lamp
where is the printed circuit board on the T45 AEL and what does it control?
Found on the inside cover
Controls operation of the lights
what is the T45 AEL comprised of?
- light operation PCB
- power source control
-connection for ships power - battery cover
