Oral Exam Questions These are in no particular order as I am remembering them as I write. Would never remember the order adrenaline was pumping.
Walk in to building handed my documents across the desk Enter room 10 minutes later Started by asking about my ships (cruise line
Generator – !E" !o voltage on genny what is the problem# $nd solution# %reaker %reaker not closing why would this be# (&nrelated to above
Propulsion What type propulsion# (' electrical 'ow does the prop p rop motor work in reverse ie moving ship astern )yclo* Synchro converters how they operate* thyristors etc.
Emergency Supplies Testing Testing emg genny Trips Trips and alarms (no trips Emg Switchboard consumers %lackout ship restart procedure Emergency lighting regs Emg e+it lights regs and supplies ,ow level lighting regs
UPS 'ow does it work# What do they supply# Testing# Testing#
Emg storage battery testing sa-ety procedures etc.
Hazardous Areas Where on board# What makes something ameproo-# What makes something Intrinsically sa-e# E+plosion proo- light /+ture sa-ety -eatures $uto isolation etc#
Steering Gear Supplies Trips and $larms Testing trips and alarms oil levels etc.
Safety What /+ed /re/ghting euipment do you have# rocedure -or a )23 release the situation given was a /re on one o- the main engines. Shut o4 valves* /re dampers and how the co3 is released and who authorises Enclosed space entry permits* regulations* what gasses you looking out -or (asphy+iates* to+ic and e+plosive %$ check start to /nish
otors and starters Star delta starter what is the purpose* why is the current less in star than delta* what would happen i- it stuck in star how would it trip# "egular motor not working he asked what the problem could be# 2ther tripping methods.
G!SS and "a# 'e only asked about my e+perience in this /eld so told him about opening up the radar and the normal daily test calls and logging comms etc.
,uckily a-ter all o- that I came out with a pass. The guy really didn5t seem like he was there to -ail you he kind o- guides you in the right direction I arrived 16 minutes be-ore my appointment and reported to reception. $-ter about 30 minutes the e+aminer called me in. 'e asked -or my discharge book and inuired what type o- vessel I was last on. 1. 7raw distribution diagram (e+aminer looked through my T"% whilst I did this. 3. Then talked through the main components o- the diagram. 8. What types o- 9enerator protection do you have# :. 'ow do you test these# 6. 9enerator circuit breaker is not closing. What could cause this# ;. Why would a generator have no voltage# <. What would you do i- a generator lost its residual magnetism# =. What could cause a generator to lose its residual magnetism# >. ?ou have an earth -ault* how do you go about tracing it# 10.What tests should you per-orm on emergency generator# 11.What can the emergency generator supply# 13.7raw star@delta starter. (2nly wanted power circuit* again he looked through my T"% 18.E+plain start@delta operation using diagram. 1:.Why do we use star@delta# 16.'ow would you know i- the motor switched to delta# (I said running lamp* or i- le-t in star it would over heat and trip on over current* so i- motor didn5t trip all was 2A# 1;.What would happen i- a motor single phased# 1<.What protection do you have -or single phasing# (this lead to 2)"S 1=.What types o- 2)" are there# (%imetallic will trip motor on single phasing 1>.2peration o- %imetallic 2)"# 30.Talk me through ' sa-ety. 31.Why do we use '# 33.'ow would you isolate a piece o- ' euipment -or maintenance# 38.What maintenance have you done to bridge euipment# 7iscussed 9B7SS battery maintenance and "$7$" maintenance. 3:.7iscussed electrical C general sa-ety whilst working on bridge euipment. 36.What E+ euipment have you come across# 3;.What does intrinsically sa-e mean# 3<.?ou have been asked to take part in a /re drill* what %$ checks would you carry out# 3=.What /+ed /re detectors did you have on board# 3>.'ow do you test these# 80.What /+ed /re/ghting installation did you have on@board# 81.E+plain operation o- /+ed /re/ghting installation# 2ral uestions 9ave me an electrical diagram o- a seawater cooling system. • •
7escribe the components What does it do
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'ow does it work What is the purpose o- the -uses What are the properties o- a -use 'ow big should the -uses be Whats an ocr* how does it work* what setting should it have. What protection does the motor have Why does a ammeter powered -rom a step down trans-ormer What is a trans-ormer What -aults could lead to a motor drawing e+cess current
$sked me about Dreuency drives briey. • •
What type o- euipment would use -reuency drives Why use a -reuency drive
What other types o- speed control are there#
$sked me about electrical distribution on 1 o- my ships • • • • • • •
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$sked to e+plaing the parts urpose o- bustie breakers and operation parameters Emergency generator* how it works* regulations etc $sked to produce a switching plan -or trans-ormer maintenance. What would you do ne+t to continue with the maintenance I- the maintenance included an I" test what else would you need Why would you need the sanction to test i.e why do you need to remove the )EB What euipment would be connected to the emergency switchboard I- you try to connect a generator to the board and it won5t connect what are the reasons
%attery Baintenance* • •
general battery maintenance uestions %attery -ault /nding
&S • • •
What is a ups Whats the purpose What type o- euipment would be connected
Dire Systems • • • •
What type o- sensors are there 'ows does the system work 'ow do you test the sensors What would your duties as an ET2 entail in a /re situation
$sked me about haardous areas
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What are haardous areas What type o- euipment would use in these areas
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E+aminer@ Br 9roark
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Show passport Testimonials )on/rm date o- birth 7ischarge book (e+amined the range o- vessels and period in rank
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F. What type o- vessels are you currently sailing on#
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$. 7iesel electric ,!9 vessels.
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F. lease draw the electrical distribution system -rom your last ship.
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F. $re the bus ties between the two sides o- the main ;.;Av switchboard normally kept open or closed#
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$. )losed
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F. What about the bus tie between the two ::0v switchboards* open or closed#
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$. 2pen
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F. Why#
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F. I- you were chie- engineer and your planned maintenance system spat out a planned Gob on a main trans-ormer during a passage -rom Singapore to )artagena what would you do#
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F. Would you carry out the Gob# 7o you -eel commercial pressure# Why#
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F. What in-ormation would you use to assist in making this decision#
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F. $s chie- engineer where would you pre-er to carry out this Gob# Why#
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F. E+plain how you would make one o- the ;.;Av @ ::0v trans-ormers sa-e to work on.
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F. 'ow is the trans-ormer earthed down#
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F. Who carries out the isolation and earthing procedure#
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F. What normal maintenance Gobs would you per-orm on a trans-ormer#
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F. What would happen i- you tried to per-orm an insulation resistance test on the trans-ormer windings now# What reading would you get#
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F. What would you then need to do be-ore an insulation resistance test can be per-ormed#
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$. Sanction to test* remove earthing connections* $uthorised person etc.
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F. (E+aminer drew an $) wave-orm Show me one -ull cycle.
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F. Why do you have harmonic /lters# What is the likely e4ect oharmonics on your systems#
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F. What is a thyristor#
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F. 'ow does it work#
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F. 'ow is the speed o- the propulsion motors controlled#
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F. What critical euipment is there onboard your ship#
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F. Why is this euipment critical#
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F. What would you put into a shipboard energy eHciency management plan#
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F. 'ow o-ten does your hull get inspected )leaned#
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F. What is the main purpose o- a underwater hull survey#
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F. What certi/cate would you look at -or in-ormation on your hull condition#
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F. What is the main di4erence in a tanker and a bulk carrier with regards to the load line#
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F. What are the main points that you as an engineer would be interested in during a load line survey#
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F. ?ou walk onboard a ship -or the /rst time as chie- engineer and you see a vent head -or an engine sump with slack bolts* what do you do#
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F. What is the procedure that you would -ollow in your company i- you believed that the ship should not sail due to sa-ety concerns.
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F. What term would be used -or something that constitutes a -ailure othe sa-ety management system#
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ET2 2ral E+am Fuestions
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7raw one electrical distribution diagram
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E+plain the diagram
9enerators •
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?ou5ve ran up a generator but it keeps -alling o4 the main switchboard J what could be wrong# What are the basics you would look -or on the switchboard panel# What are the circuit breaker protection trips -or a generator#
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Is there actually such a thing as overvoltage# E+plain it.
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What is reverse power# What does it cause#
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?our generator is running but there5s no voltage* what could have caused it and how would you /+ it# Where is the residual magnetism in a generator# What windings would you connect the /eld ashing battery to# What are the diodes -or in the e+citation system# E+plain what a diode is and what it does. What is the mechanical euivalent to a diode# Would a problem with one diode a4ect the e+citation output# What else could be wrong in a -aulty e+citation circuit# What is an $"# What does it do# What -aults can occur in an $" circuit# What is a synchroscope# Two generators are on the board at ;3'. 'ow would you reduce their -reuency#
Botors •
Bethods o- speed control -or an $) motor.
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What is a thyristor# What does it do# 'ow does it work# 'ow does it change the speed o- a motor# E+plain how a synchroconverter works. E+plain ulse Width Bodulation. Why is it recti/ed and then inverted back to $)#
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What are the problems with starting large motors#
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'ow much is the starting surge current o- a large motor#
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'ow do you alleviate the problems o- starting a large motor# 7raw a star@delta or autotrans-ormer power circuit. What is the relationship between line voltagesphase voltages* line currentsphase currents -or star and delta# Euations..
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What i- the star contactor is stuck in#
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What i- all three contactors are stuck in#
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Drom a 72, starter power circuit* how you would con/gure the motor to change direction# 7raw it with the correct components. (not Gust swapping two phases roundK ?ou have a motor with a running current o- 10$ and a starting current o- ;0$ J what rating o- -uses does the motor need# What is the inverse time characteristic#
Trans-ormers •
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What is a trans-ormer# $ trans-ormer reuires planned maintenance while your ship is at sea J would you do the work# Why not or why# E+plain what a switching programme is and how you would isolate a trans-ormer.
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Where do you apply earths when earthing down a trans-ormer# What euipment is used to apply earths# E+plain how you use an ' probe -or proving a circuit dead. 'ow would you I" test a trans-ormer#
'igh oltage •
Why do we use high voltages on board ship#
)ircuit %reakers •
What5s the di4erence between , and ' circuit breakers#
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'ow does a vacuum circuit breaker operate#
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Why do you have bus tie breakers#
Emergency 9enerators •
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I- you lose mains power how does your emergency generator start# (what actually takes place -or it to start# Bost common method used to start an emergency generator# 'ow uickly must an emergency generator run up and be connected to the board* according to regulations# What is -ed o4 the emergency switchboard#
Dire detection •
What other /re detection components are there# (other than smoke* heat* ame detectors
%atteries
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Typical speci/c gravity levels -or a -ully charged lead acid battery# Typical voltage levels o- a -ully charged lead acid battery# Where else would you /nd batteries on your ship# What euipment do they -eed# $t what voltages do they -eed the euipment you mentioned#
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What is a &S#
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Why do you have &Ss#
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Typical voltage output -or a &S#
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Where do you /nd &Ss#
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What %ridge euipment is -ed by a &S#
%ridge Euipment •
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'ow do you do an on@load test -or 9B7SS euipment# (3 waysK. The 7" is in alarm whilst you5re in port. What could be wrong#
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What euipment -eeds into the 7"#
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Should an $IS be switched o4 in port#
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The ship is in port and the echo sounder is switched on but nothing happens* what could be wrong# What would happen i- the echosounder worked whilst the ship was in port# 'ow does an echosounder work# Why else (other than power supply would an echosounder not work# What other euipment has problems with seals -ailing and conseuently* water ingress#
Electrical Shore Supplies •
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?our ship needs to take an electrical shore supply J what in-ormation does the electrical company need# Where would you typically /nd a shore connection point on board a ship* outside o- the main engine room# 'ow many cables -rom shore will be connected to your shore connection board# 'ow can you check that the phases o- the shore connection cables are in the correct seuence so that your large motors connected to the switchboard won5t all run in reverse#
Insulated !eutral and Earthed Systems •
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2n a typical ship* not high voltage* are the electrical systems earthed# What would one -ault on one phase o- an insulated neutral system cause to happen# Would you even know it5s there# What would two -aults on the same phase o- an insulated neutral system cause to happen# Would you know you had two -aults# What about the other phases#
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What are the dangers o- a short circuit across phases#
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What does a generator !E" do#
Earth Dault Tracing •
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'ow do you carry out earth -ault tracing# 7o you have to care about which phase is red* yellow or blue when earth -ault tracing#
"e-rigeration System
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!ame the electrical components in a re-rigeration system.
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What is a compressor#
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What is inside a compressor#
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I- a compressor is switching on and o4 J is it -air to think the problem is the motor itsel-# What else could be the problem# What could be happening to the motor as the supply keeps switching on and o4# Will the -uses blow# Will the contactor su4er# Will the 2)" trip# I- the contactor is stuck closed* what could this cause#
Emergency $ctions •
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There5s a /re in the galley J what are your duties as an ET2# What are you looking to isolate# What are you not looking to isolate -or as long as possible# Where would you do these isolations# What do you hope the galley sta4 have done prior to evacuating the galley i- there was a /re# What do the emergency crash stops in the galley do# In the adGacent areas o- the galley J in this case the crew mess and a passenger restaurant* what else are you looking to isolate in these areas#
2thers •
,ow ,ocation lighting J $) supply or 7)# ETO MCAOr al sq ues t i onSummer2014
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Dr a w po werDi s t r i but i onande x pl ai n
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gener at orr unni ng butnov ol t agel i s tt hepos s i bl epr obl ems
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fi x edfi r efi ght i ng
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bat t er yc hec k s
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e me r g en c yge ne r a t o rc h ec k s ,h owmu c hf u el d oe si th av e ?
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emer genc ydi s t r i but i on
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UPS
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St ardel t adr a w ande xpl ai n,whathappensi fs t uc ki ns t ar ?howdowek no wi t s s wi t c hedo v er ?wh ydoess t ar t i ngi ns t arr educ ec ur r ent
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BAch eck s
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a ddr e ss abl efi r efi gh t i ngs y s t e ms
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e nc l o se de nt r ypr o ce dur e
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a swh att hepu r p os eoft h ec y c l owa s
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HVs a f e t y
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GMDSSchecksandanyot herbr i dgeequi pmentIhadwor kedon
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Howt oc l eanupandoi l s pi l l whatwoul di do?wher edoest heoi l goaf t ert hebi l ge?
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s hor ec onnec t i on,l i mi t at i onsandpr oc edur e Go in, hand in your TRB and Workbook. Sit for 15-20mins and he wi !a you in. 1. "raw me your ty#i!a #ower distribution.
2. $%#ain it in &enera, why ea!h !om#onent is where it is and what is it used for. '. (a)e * e)er worked on isoatin& transformers. Su!h as ++0-++0. +. $%#ain the o#eration and #ur#ose of the ower ana&ement System. 5. What ty#es of thrusters were on my shi#. /. Testin& and !he!ks on $mer&en!y Generator . What methods of startin& the $mer&en!y Generator are there. . (ow often do you test $mer&en!y Generator. . What Ser)i!es does an $mer&en!y Generator #ro)ide. 10. What is a shore side !onne!tion. 11. Why is a shore !onne!tion used. 12. *f shore #ersonne handed you the shore !abes where woud you !onne!t them. 1'. (ow woud you ensure the shore !onne!tion is ok when you !onne!t it. 1+. 3S, what is it. 15. (ow does 3S Work. 1/. What ser)i!es use 3S systems.
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1. (ow do you safey o#erate a Waterti&ht "oor. 1. 4an the waterti&ht doors be o#erated anywhere ese. 1. otor is runnin& but tri#s out what !oud be #robem. 20. 4he!k 4R but sti tri##in&. 21. 4he!k !onta!tor, sti tri##in&. 22. ossiby o)erhau motor to !he!k bearin&s, *R test windin&s , sti tri##in&. 2'. 4he!k 67" on motor shaft. 2+. (ow do you safey isoate a #ie!e of e8ui#ment 25. What do!umentation needs to be !om#eted for 6 and ( *soations 2/. What differen!es are there from 6 and ( isoation. Remember San!tion to Test 2. (ow do you enter an en!osed s#a!e, what needs to be in #a!e. 2. (ow do you !arry out B7 4he!ks. Start to finish. 2. What fire fi&htin& instaations are onboard. '0. (ow do you o#erate them. '1. 4an they be o#erated in !ertain s#a!es, or a at on!e. Se#arate. '2. What #ro!edures are foowed before reease of 42 ''. What work ha)e * done on na)i&ation e8ui#ment '+. 7ny #ro!edures to foow when workin& on e8ui#ment.
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started off ookin& at the #arti!uars of my ast shi#s, then asked about boier and steerin& &ear 9rotary )ane: then 8uestions 1. steerin& &ear - aarms, how woud you know if it was sin&e #hasin& 9its the one motor that doesnt ha)e an o!r: 2. draw the distribution dia&ram and e%#ain it '. then dis!uss motor startin& methods, how woud you redu!e oad when startin& an en&ine room air !om#ressor, we drain )a)e o#en so ess me!hani!a oad +. emer&en!y swit!hboard, i&htin&, soas re&s 5. emer&en!y &enerator tests /. s#oke about #ro#usion systems . s#oke about h) motors su!h as bt, st, a! !om#ressors - s#oke about refri&eration . taked about shore !onne!tions . s#oke about fire fi&htin& fi%ed instaations 10. s#oke about !o2 reease 11. s#oke about en!osed s#a!es. 12. ba set !he!ks 1'. workin& on h) e8ui#ment, e#tw, stored ener&y 1+. h) e8ui#ment isoation and san!tion to test 15. risk assessment 1/. &enerators - oss of )ota&e - a)r and residua ma&netism, fied fash 1. 4ant think of any more, but wi et you know if * do
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"istribution dia&ram () swit!hin&, *soation #ro!edures entry to ha;ardous areas, #ro!edures rote!tion de)i!es on &enerators and #rime mo)ers ain #ro#usion, method of !ontro, #wm et! 7u%iiary e8ui#ment $mer&en!y swit!hboard Batteries, what they su##y Breaker maintenan!e
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1. he drew a distribution system and then &ot me to tak about fauts that !aused a ba!kout, restoration 2. Boier, fauts, !he!ks and faiure to start '.emer&en!y swbd, whats fed and why +. fire fi&htin& /. ( - #ermit to work, sa!tion to test . ariabe s#eed dri)e - this threw u# some dis!ussion he beie)ed that sny!hro !on)ertors o#erate by )aryin& the )ota&e so we taked aroun that for a bit and he=s &oin& to read u# on it. . syn!hronisin& &enerators . na) i&hts and brid&e e8ui#ment 10. batteries and s#e!ifi! &ra)ity et! 11. Star deta - a&ain we had a bit of a !hat about the fa!t that in#ut ine !urrents woud be the same e)en if your &ettin& it stu!k in star. 12. !ant think of mu!h more.
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1. "raw distribution from first shi# 2. Tak about it. >$R, harmoni! fiters, #ro# !on)erters?t%=s. '. Why is ( a non insuated system +. Why shoudn=t you o#erate the fwd and aft er swbds !osed if main bus tie on h) board is !osed. 5. Star deta startin&, draw and e%#ain o#eration /. Why is deta runnin& !urrent ower than star . Syn!hro !on)erters, taked oads about it, firin& se8uen!e, tor8ue, smoothin&. . Generators, 7R, why trimmers are there, how e%!itation works, fied fashin&. . ( isoation of !on)erters?#ro# t% 10. Batteries, &mdss, stora&e et!...
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11. $m &enerator startin& 12. Syn!hronisin& &ennys 1'.
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1,$R=s for +, "ifferen!e between ( earthh faut and 6 earth fauts, 5, Swit!h board #rote!tion, /, Breaker #rote!tions , Syn!ros!o#es and syn!ronisin& ma!hinery, , 7R and $%!itation 9
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(e then sent me out of the room as he was bein& e%amined by some other dude in the room, they must ha)e had a brief dis!ussion about the 8uestions he had asked me. * then !ame ba!k in the room after 2-' mins and he asked about oad sharin& 7G7*>, 2+, *f one &enny is /00kw the other is +00kw what do we ha)e to !ontro to ensure they share oads e)eny 25, the bus fre8uen!y no has dro##ed to 5 (; what wi you do@ 2/, Breaker wont !ose on swit!h board, what !ooud be #robem, 9 R$S$T button on breaker: 2, Aour on a !ar&o shi# and you ha)e one ift for !rew, the !hief asks you to fi% it but you dont ha)e a #ermit to work. what woud you do@
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S(R$ 4>>$4T*> R4$"3R$ 1.Turn off and isoate ( "G sets?en&ines unti there is one remainin& on the ( board. 9*soated so that S System doesn=t turn another d& set on after you e)entuay kno!k off the ast one:. 2. Turn on $"G '. Turn off ast remainin& "G Set and isoate +. *soate //?++0 transformers 9ba!kfeed: 5. turn off a oads on main ++0 swb... so that when shoreside does !onne!t fu oad of ++0 board isn=t suddeny a##ied /. 4ose shoreside !onne!tion . do se8uentia start se8uen!e
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R7"7R 7*>T$>7>4$C Workin& at hei&ht TW, taked about $, !ommuni!ation with de!k offi!ers not to transmit on e8ui#ment as man is workin& aoft 9warnin& si&ns on su!h e8ui#ment:, !he!kin& of ma&netron !urrent on!e new one instaed 9o!kin& r adar in one dire!tion whie doin& this:.
ET2 )o)
Deedback -rom candidates
Fuestions based on
1 7raw a typical ship5s electrical distribution systems (e+ample your last ship a E+plain all components* tie breaker etc why are they there. b
Earthing arrangements
c $chieving 380v (generation
d Dunction o- isolation trans-ormers 3 Emergency generator (what is it connected to.. # a 7aily )hecks b Weekly checks c Interlocks* main circuit breakers* protection why is this necessary # 8 Earthing* permt to work* sanction to test* a Botor start* tripping current* (K.Impedance calculations b 8 phase J Star7elta starter with control circuit c ,ist7iscuss other types o- motor starts @ were these would be -ound : Transitional ower "euirements (ie trans-er o- Bain ower to Emergency ower 6 Systems J general description o- %ridge* components* and redundancy reuirements in emergencies <
Entry in to 'aardous environments* checks* permits
= 2ily water separator e+planation. > 9eneral Electrical )hecks 10
Botor insulation tests.
Try to emphasise sa-ety aspects in answers to uestions "e-erence )2SW2 and speci/c rules pertaining to the vessels with which you have e+perience and are using to illustrate your answers
