P&D Flashcards
How many Diesel generators are fitted to a Generic Distribution System?
4
What does EDC stand for?
Electrical Distribution Center
What does MCCB stand for?
Moulded case circuit breakers
What are the 5 main breakers in a Generic distribution system?
- Supply breaker
- Shore supply
- Bus Bar linking breaker
- Interconnector breaker
- Feeder breaker
What is the Power book & when is it used?
- Shows the distribution of all 440v services.
- Used when tracing which services are fed from which fuse panel, transformer, MCCB and EDC
What is the Lighting book and when is it used?
- Shows 115v/230v
- For tracing systems (Same as power book)
What is the Reference book and when is it used?
- Used in conjunction with power book
- Lists all fittings, number fitted,componentt symbols & pattern numbers
What is the ratio for 440v fuses regarding fuse discrimination?
3:1
Ratio for 115v fuses regarding fuse discrimination?
2;1
What is breaker discrimination?
With breaker & fuse discrimination, you can’t get a fault on a mess deck kettle to trip a main generator.
What does MCR mean?
Machinery control room
What does PCP & SCP mean?
- Primary control position
- Secondary control position
List 6 meters fitted to a switchboard generator section
- Voltmeter
- Ammeter
- KW meter
- Frequency meter
- Syncroscope
- Earth fault indicator
Where are the breaker operating switches found & what are they called?
Discrepancy switches
Found In PCP
What are the rules regarding the earthing of the ship when connecting to shore supply
It must always be earthed to jetty or ship alongside by at least 2 points
What is used to confirm correct phase rotation with respect to shore supply?
The phase sequence indicator (2 lamps) the right one should be brighter
What would happen to a motor if phase rotation is wrong?
it would run backwards
Name 3 hand changeover switches
- Normal/Alt
- Normal/Emergecy
- N/A/E
Name 3 kinds of changeover switches
- Hand changeover switch
- Automatic Changeover switch
- Remote operated changeover switch
Where are 440v earth testing facilities found?
Earth indicator light on switchboard, some have audible alarms
Why are there seperate 115v testing facilities?
115v is a transformed supply & the secondary winding is not physically connected to the primary winding
What does C&C mean?
Control & communications (switchboard)
Define what a converted supply is
It has its voltage &/or freq changed form 450v, 60hz
What are the voltages used in the c&c Switchboard?
- 24v DC
- 115v
- 400 hz
What & where is the earth testing facilities for 24v dc?
- The earth test panel on switchboard
- It is a push button with intergral lamp fitted to switchboard
What does TRU mean?
Transformer rectifier unit
What does RTR mean?
Rationalised transformer rectifier
What are the catogories of batteries?
- Primary
- Secondary
What are charctaristics of primary batteries?
- Dry cells
- Not rechargable
- Small
- Thrown away when done
What are the characteristics of secondary batteries?
- Wet Cells
- Rechargable
- require specialist recharging equipment
What is the capacity of a battery measured in?
amp-hour (ah)
What is the voltage of a fully charged cell?
2.1v
What is the voltage of a discharged cell?
1.75v
How many Deisel generators are fitted to type 23’s?
4
What is the output of generators fitted to a 23
& why is it produced?
- 1.3MW
- 600v
- 61.2hz
- 3 phase
- 450v does not give a large enough range of speeds
What are the 7 breakers fitted to a 23?
- Supply
- Interconnector
- Shore supply
- EMACB
- motor generator feeder
- motor generator supply
- Diesel gen alt supply
What does the converter regulator do?
Converts & regulates the voltage at 750v DC
What is the voltage required for ships services?
450v generated by motor generator
How may types of electric distribution panels fitted to 23’s
3 EDP’s
What are shedable services?
Provide power to non essential equipment
What would happen if you were to loose both motor generators?
66v gen can be reconfigured to supply 450v via a 4 postion switch at the back of switch board
What 5 services does the emergency switchboard supply?
- Steering motors
- HPSWP
- Sickbay
- Smoke clearance exhaust fans
- Portable pump sockets
What are EMACB?
- Electric motor air circuit breaker
- supplies 600v to electric propulsion motor
Why is electric Propulsion prefered when in a sub?
- Reduce noise
What SPRM & knots do 2 diesel gens produce?
- 65 SPRM
- 8-9 knots
What SPRM & Knots do 3 diesel gen produce?
80 SPRM
10-12 Knots
What SPRM & Knots do 4 diesel gen produce?
90 SPRM
14 Knots
In event of damage to SCC how are propulsion motors controlled?
Local control panels (LCP’s)
Describe water cooling for propulsion motors
Cooled by water cooled air circulated around motor
Describe the normal & emergency cooling system for the converter cubicle
If heat exchanger fails,2 emergency inlet panels are removed allowing air to be drawn into cabinet by fan
When are the navigation lights tested and by who?
- Daily 1 Hour before sunset
- By the duty ET(ME)
Whose permission must be gotten to test navigation lights?
- OOW at sea
- OOD alongside
Where are navigation lights controlled from & switched on & off?
- Bridge
- Operations room (VCS)
List all statutory lights, their colours & location
- Side lights ( Stbd green, port red)
- Masthead steaming lights (white)
- Stem lights (white)
List the 4 main components of a flourescent light fitting
- Starter
- Tube
- Choke coil
- Switched supply
In the event of action damage to the SCC, how can the propulsion motors be controlled?
LCP in machinery space
What are the LV and HV filters used for on the type 45 distribution system?
The purpose is to smooth & filter the voltage supply
What are the 3 special operations lights?
- NUC-Not-under-command
- RAS- Replenishment at sea
- MOB- Man overboard
