1.
M.E Lubrication system drawing showing how bearings are lubricated.
a.
The
above sketch shows the method of conveying L.O to M/E con-rod top end, Bottom
end & main bearings.
b.
The
Main L.O.P/p draws oil from the Sump and discharges via filters & coolers to
the two manifold pipes.
c.
From,
the lower manifold pipe, connections are taken to deliver oil to each main
bearing upper half, thrust block, chain drive.
d.
From
the upper manifold pipe, oil is supplied to each X-head via a telescopic pipe
arrangement.
e.
The
oil entering the X-head is branched off in several directions to supply L.O to
the X-Head or top-end bearing upper half.
2.
Explain starting system of Aux Engine.
3.
Advantages of Hydraulically operated exhaust valve.
a.
Smooth
Operation
b.
Equal
wear in each area of exhaust v/v.
4.
Piston rod stuffing box purpose.
It acts as a gland between the Scavenge space
& Crankcase so as no object or L.O gets intermixed.
5.
Securities for crankcase explosion.
a.
Oil
Mist Detector Alarm.
b.
Crankcase
Relief door
c.
Crankcase
Breather
d.
Bearing
Oil temperature alarm.
6.
What to do if Oil Mist detector alarm initiated.
a.
Accept
the alarm.
b.
Slow
down the engine.
c.
Inform
Bridge & C/E.
d.
Press
Engineers alarm.
e.
Check
whether the alarm is true or not, by resetting. If alarm comes again, that
confirms its surety.
f.
Start
the stand by L.O P/p i.e increase lubrication.
g.
Stop
the engine as you get permission from bridge.
h.
Open
indicator cock.
i.
Engage
turning gear & turn the engine using turning gear, so as to avoid stucking
of piston.
j.
Let
the L.O. P/p running.
k.
Get
the fire extinguishers ready.
l.
Make
sure no one is standing behind the c/case relief door.
m.
Wait,
until the alarm goes off.
n.
Stop
the L.O. P/p.
o.
By
hand feel, whether C/case has cooled down.
p.
Now,
open the C/case door taking door as a shield.
q.
Ventilate
the C/case using blower.
r.
Go
inside the C/case; make sure no naked lamp taken inside, boiler suit free of
dust & oil, and no object in the pocket.
s.
Check
where the hot spot occurred.
t.
Repair
that part.
u.
Now,
start the L.O P/p and check flow of oil to all parts.
7.
What to do in case of scavenge fire?
a.
Accept
the alarm.
b.
Inform
Bridge & Chief Engineers.
c.
Press
Engineer’s alarm
d.
Slow
down the engine.
e.
Increase
the Cyl. Oil Lubrication.
f.
Wait
for the exhaust temperature to comedown.
g.
If
exhaust temperature not coming down, then take permission from bridge to stop
the engine.
h.
Open
indicator cock and engage the turning gear, to piston getting jammed.
i.
Now,
use the fixed fire system attached for fighting fire in Scavenge space.
8.
Bearing clearances of Main Engine- how to check?
a.
Method
1.
i. After removing the
bearing top cover and shell, a special ‘Bridge gauge’ is placed.
ii. The clearance is
taken by placing a feeler gauge between the bridge gauge & the journal.
9.
Safety devices on Main Engine?
a.
Cylinder
relief valve.
b.
Crankcase
relief valve.
c.
Scavenge
space relief v/v.
d.
Fuel
p/p relief v/v.
e.
Starting
air relief v/v.
f.
Turning
gear interlock.
g.
Automatic
shutdown of engine due to low L.O. Pressure.
h.
Automatic
shutdown of engine due to High/low temp. in various system.
i.
Shutdown
of engine from the bridge should the communication with E/room fail.
j.
Overspeed
Trip
k.
Oil
Mist Detector
l.
Crankcase
breather
m.
Bearing
oil high temp. alarm.
n.
Scavenge
space high temp. alarm
o.
Automatic
Starting Air V/v.
p.
Blower
interlock.
q.
Flame
arrester.
r.
Bursting
disc.
10. Safety in
boiler gauge glass.
Non-return ball cock is provided at the water
side of gauge glass.
11. How to blow
through boiler gauge glass.
12. Reasons for
Boiler Blow back and what to do in case of boiler blow back.
13. Setting of
safety valve. What provision on safety valve to avoid tempering of setting?
14. Accumulation
of pressure test on boiler why and how done.
15. How to blow
down boiler.
16. Why boiler
not blown down to bilges.
17. What tests
carried out on Boiler water? Normal values?
18. Oil
returning with condensate. Indications? What to do?
19. What to do
if oil goes to boiler?
20. Explain the
refrigeration system? How does it maintain different temps in different rooms
automatically?
21. Cut outs of
fridge compressor.
22. Reasons for
HP cut out.
23. What will
happen if you start fridge comp with discharge v/v shut?
a.
The relief valve attached in the discharge side of compressor will
lift & the refrigerant will re-circulate to the suction side.
24. What is
short cycling? Causes?
25. How to
check Bumping clearance of air compressor and adjust.
26. Safeties on
an air compressor.
27. What is provided
to save water side?
28. Characteristics
of a centrifugal p/p
29. Why
centrifugal p/p does not have relief valve.
30. How to
select gravity disc of purifier if do not have chart
31. What are
specifications of Boiler/generator and Main engine on your ship.
32. Causes of
turbocharger surging? What to do?
33. Lift of
fuel valve.
34. Purpose of
hunting gear.
35. Why to blow
down boiler?
36. What will
you for uptake fire?
37. Contents of
Boiler flue gas
38. Safematic
design in steering
39. Difference
between two and four stroke Engines
40. Effect of
Moisture and Air in refrigeration system
41. Desirable
properties of refrigeration oil.
42. Difference
between Mineral and Synthetic oils
43. What is
volumetric efficiency of Compressor?
44. How you
determine Engine power.
45. Draw cards
for early and late injection
46. What will
happen if ref compressor is undercharged or Overcharged?
47. In an air
compressor what will happen if the Suction valves leaky or discharge valves
leaky?
48. What is
setting of Boiler safety valve?
49. How you
test boiler alarms and trips?
50. How is
pressure testing of Boiler done?
51. What is
difference between pressure gauges of air compressor and fridge compressor?
52. Is there
difference between Lube oil pressure of Fridge compressor and air compressor?
53. Safety
device on Fridge compressor.
54. What is
function of TEV in fridge compressor?
55. Procedure
for collection of Lube oil sampling?
56. Why
intercoolers/after coolers used on air compressor?
57. Why use
multistage compressors?
58. Working of
oil mist detector?
59. 2 stroke
and 4 stroke timing diagram?
60. Why two
springs in aux engine inlet exhaust valves?
61. Why do you
blow through engine before start?
62. What is
difference between aux engine and main Engine Governors?
63. What was
specific fuel consumption of your last ship?
64. How will
you know without opening anything that it is two strokes or 4 strokes Engine?
65. Why LO of
different TBN used For ME Cylinder oil and crankcase oil?
66. How to
calibrate Oxygen Analyzer?
67. Parts of
Cross Head?
68. How
lubrication is achieved in cross-head?
69. Power
calculation for Main Engine?
70.
Draw PV Curve for Otto cycle, Diesel cycle, Carnot Cycle?
72. How to calculate intermediate
stage pressure in multi stage compressor?
73. Where piston palm will be
connected?
74. Material of fusible plug?
75.Clearences in cross head n their
values
76.Types of threads
77.Types of taps and dyes.
77.Types of taps and dyes.
78. What are the differences
between INDICATED PRESSURE, MAX. PRESSURE, MEAN EFF. PRESSURE.
HOW THEY CAN BE FOUND?
79. WHY WE DONT TAKE INDICATOR DIAGRAMS FOR 4 STROKE ENGINES?
HOW THEY CAN BE FOUND?
79. WHY WE DONT TAKE INDICATOR DIAGRAMS FOR 4 STROKE ENGINES?
80. When we take sounding of a
tank, its volume is calculated by its manual so my question is what is the name
of this manual? if it has name?
81. What is the use of Flux in
welding electrode?
82.
Why belt is used to drive refrigeration compressor by motor? Why
coupling is not used?
83. What is the function of wear
ring?
84. Why
friction clutch used in purifier?
85. Why
boiler water tests are carried out?
86. Safety devices in the air starting line from air bottle to main engine?
87. How to gauge condition/efficiency of Cyl. Lubrication?
88. Various fittings of boiler?
Electrical
Q & A
1. What is special about steering gear safety.
It has got overload alarm at 150% and
short circuit trip.
2. Maintenance of alternator what all to do.
(a) Clean the felt/ air filters.
(b) Remove dust/ dirt from the rotor.
(c) Clean the connections and put some
petroleum jelly.
(d) Check the air gap with the plastic
feeler gauge.
(e) Check the lub oil level in bearing.
(f) Insulation resistance to take with
megger.
(g) Check condition of winding.
(h) Carry out continuity test.
3. Purpose of air gap and how checked.
To avoid the mechanical contact between the
stator & rotor and to determine the condition of the bearing. Measured with
the help of feeler gauge.
4. Trips on air circuit breaker with values
5. conditions for paralleling alternators
(a) Frequency
(b) Phase
(c) Voltage
6. How to parallel alternators
There are three methods of Paralleling
alternators:-
(i) Dark lamp method
(ii) Bright lamp Method
(iii) Synchorscope
7. Why megger is used to test insulation and not multi meter
Megger is used to test insulation because it
has higher range say up to 500V.
8. Suppose a motor is not starting what checks u will make
Electrical Checks:
a. Check the connections.
b. Check, if has tripped, then reset
and try to start.
c. Check supply is coming from MSB
or not.
d. Check single-phasing has not
occurred.
Mechanical:
Check the coupling between the motor
and driven part is not too tight.
9. Suppose a motor is running hot what checks.
1.
Single-phasing
2.
Fan
is working or not.
3.
Overload
is occurring.
4.
Check
condition of bearing.
10. Why insulation resistance checked and how?
A measurement of the insulation
resistance gives the best guide to the state of health of the electrical
equipment.
- Disconnect the
electrical supply.
- Refer to the
electrical circuit & manufacturer’s instruction before testing.
- Measure the
insulation of the windings to the earth and as soon as possible when the
machine is just hot after it has stopped. The minimum value should be
- 1 MW.
11. Why motor insulation deteriorates
- Moisture –
results in decrease in the measured value of insulation resistance.
- Dust & dirt
deposits – reduces insulation resistance & failure of insulation due
to oxidation.
- Oil & Grease
– prevents heat dissipation & causes dirt and dust to settle on the insulation.
- Ageing – over
the period of time the insulation deteriorates due to it getting affected
by temperature variation, mechanical stresses, vibrations, moisture and
some varnish tend to become hard with age & crack during the
operation.
- Temperature –
Excessive temperature dehydrates and oxidizes the insulation, making it
brittle & disintegrate under vibration & shock.
12. If water goes to motor what you do.
1)
Disconnect
the electrical supply.
2)
Put
MEN AT WORK tag.
3)
Remove
the coupling bolts.
4)
Now,
lift the motor using lifting gear & put it on a clean place.
5)
remove
the cover & fan.
6)
Take
out bearing & the shaft.
7)
The
salt contamination must be removed by thoroughly washing with clean fresh water (preferably warm) or if possible
, distilled water.
8)
De-greasants
must be used if it is found that there was ingress of oil.
9)
Spirits
or alcohol may be used to clean contacts.
10) Dry the motor with
dry air & then switch on its heaters or use powerful lamps. During this
process , keep its inspection covers open to permits moisture to escape.
11) Put the varnish on
the winding & let it dry.
12) Check the insulation
resistance. If it is ok then assemble it back & put it for use.
13) The motor must be
started on less load & its current monitored for few hours to confirm its
satisfactory operation.
13. How do you test that Megger is working Ok
14. What are portable electrical testing instruments used in ER
a. Clampmeter
b. Megger
c. Multimeter
d. Tester
15. What is harm if reverse power flow?
Motoring effect will take place & can damage the prime mover.
Motoring effect will take place & can damage the prime mover.
16. Why preferential trip provided Purpose?
Preferential trip is provided to
safe guard the machineries which are important for safety of ship & safety
of personnel onboard.
Preferential
trips are designed to disconnect the non-essential services i.e., Breakers
controlling Air Conditioning, Galley power, blowers, refrigeration) in the
event of partial overload or partial failure of the supply, with the aim of
preventing operation of the main breaker trip & loss of power to essential
services.
17. How do you test emergency generator?
a. Regular or weekly testing of the
emergency generator should include simulation of the loss of normal power.
b. The start up equipment may be
provide a push button to interrupt the normal voltage supply to the panel which
then triggers the start sequence.
c. Loss of main power supply can
easily be simulated by pulling a fuse in the auto-start panel which supplies
the under voltage or under frequency relay.
d. This no load running checks should, when
practicable, be supplemented occasionally by a proper load test. This requires
the disconnection of the normal mains power while the emergency generator is
loaded upto near its rated value.
18. How do you check press and temp alarms. What equipment used for
same
19. If you get earth fault alarm what you do?
a. Accept the alarm.
b. First of start isolate the breakers one
by one.
c. Then, check where the alarm has came
& should be eliminated when located.
d. Damaged conductor insulation must be
repaired.
e. Dampness or moisture in insulation must
be dried out by gentle heat & precautions should be taken to prevent future
ingress of moisture.
f. If dirt is the cause, then a thorough
cleaning with electro cleaner solvent should be applied & clean.
20. If on starting Generator you find that voltage is not building
up what you do?
Residual magnetism is lost. So
supply power from outside by connecting battery.
21. What equipment emergency generator supplies.
(a) For a period
of 3 Hrs at Emergency lighting at every muster & embarkation station.
(b) For
a period of 18 hrs at:-
(i)
In all service &
accommodation alleyways, stairways & exits, personal lift cars &
personnel lift trunks.
(ii)
In the machinery
spaces & main generating stations including their control positions.
(iii)
In all control
stations, machinery control rooms, and at each main & emergency
switchboard.
(iv)
At all stowage
positions.
(v)
At the steering gear.
(vi)
At the fire pump
& in all cargo pump rooms.
(vii)
The navigational
lights.
(viii) VHF
& MF Radio installation.
(ix)
The ship earth radio
station.
(x)
At all internal
communication equipment
(xi)
The fire detection
& fire alarm system.
(xii)
Intermittent
operation of the daylight signalling lamp & all integral signals that are
required in an emergency.
22. What is diff between AC and DC?
The difference
between AC and DC is that AC is an alternating current (the amount of
electrons) that flows in both directions and DC is direct current that flows in
only one direction;
The wires outside of our house are
connected at two ends to AC generators. DC is found in batteries and solar
cells.
alternating current varies with time,
sinusoidally... where as DC remains steady.
23. What is rms value?
The RMS value
of an alternating current is also
known as its heating value, as it is a voltage which is
equivalent to the direct current value
that would be required to get the same heating effect.
24. What maintenance carried out on Lead acid batteries.
a. Connection to be checked for
tightness.
b. Casing surface to be kept clean.
c. Terminals are protected with
petroleum jelly or Vaseline.
d. Specific gravity to be check with
hydrometer.
1.21 Charged Condition
1.18 Discharged
Condition
e. Batteries to be topped up with
distilled water.
f. Check & clear vents to ensure
H2 gas produced is vented
Safeties to be observed while operation
& maintenance.
i. Use hand gloves & safety
goggles while adding distilled water, shifting of battery, or checking sp.
Gravity.
ii. Use insulated spanners to
tighten terminals (No Sparking, short-circuiting should take place)
iii. Use plastic bottle or jar to
add distilled water.
iv. Should not be left in discharged
condition for long period.
v. If adding acid, then first put
little Acid, then add water & do the same process.
vi. No naked lights to be taken
inside.
vii. No smoking inside battery room.
25. What precautions you will take before entering battery room.
a.Inform the bridge & the engine
control room
b.Check the oxygen content.
c. Should be ventilated properly.
d. All PPE to be donned properly
& rubber hand gloves to be used.
e.
No Naked lamps to be taken inside.
f. .
26. What is meaning of power factor. What is best value. What is
normal value onboard. How do you improve?
Power
Factor :- The power factor of an AC electric power system is defined as the ratio of the real power flowing to the load to the apparent power and is a
dimensionless number between 0 and 1
The
best value is 0.85. The normal value onboard varies in between 0.8 to 0.9.
Power
factor can be improved by connecting a Capacitor in parallel.
27. What is meaning of saying current and voltages are in phase
28.What happens to resistance of conductor when temp rises.
Resistance is directly proportional to
temperature.
So, resistance will increase if temperature
rises.
29. Types of starters in ERoom
a. DOL (Direct On-Line)
b. Star-delta
c. Auto-transformer.
d. Face plate starter
30. Types of Motors in Eroom
a. Induction Motor.
b. Synchronous Speed Motor.
c.
DC Motor.
d.
Shunt motor
e.
Series Motor
31. How do you check continuity.
By using the multimeter, continuity is
checked. Continuity is checked between the earth & the motor connection.
32. Meaning of open and short circuit. How checked.
33. Voltage generated in megger.
500 V.
34. What is explosion proof equipment?
It is an equipment:
(a) Having an enclosure
capable of withstanding an explosion within it of a specified flammable gas or
vapor & preventing the ignition of the specified flammable gas or vapor in
the atm osphere surrounding the
enclosures by the sparks, flashes or explosion of the gas or vapor within.
(b) That operates at such
an external temperature that a surrounding flammable atm osphere
will not be ignited.
35. What precautions to take while using megger ion circuits
containing Electronic components.
36. What precautions to take before starting a work on electric
equipment?
a. Do get to know the electrical circuit or
system.
b. Rubber gloves, insulated tools to be used.
c. Portable lamp, if used should be fully
insulated without metal guards.
d. Precautions must be observed to isolate
and lock off the apparatus. Where, fuses are there, these should also be
removed.
e. Before commencing work, it should be
confirmed that the system is dead using live line tester.
f. Men at Work signboard to be put.
37. how does tube light work.
38,. Trips on Electric Motor.
Short Circuit trip.
Overload trip.
Reverse power trip.
Reverse current trip
Fuse
39. Overhaul of an Electric Motor.
a. Disconnect the electric circuit.
b. Isolate the system.
c. Remove the fuse & check the
electric supply is not coming.
d. Put MEN at Work tag.
e. Remove the coupling bolts.
f.
Lift the motor with the help of lifting gear.
g. Open the end cover & remove
the fan and clean the fan.
h. Remove the bearing and renew it.
i.
Check the condition of winding visually & check the insulation
resistance by using megger.
h. If low, then apply varnish on it & dry
it with gentle heat.
i. Check the continuity.
j. Assemble the motor.
k. Before putting it into operation, check
the load being taken & any noise coming from it.
40. Purpose of AVR
AVR :- Automatic Voltage Regulator
The
AVR is used as an exciter. The
purpose of AVR is to maintain terminal voltage of an alternator constant on
load.
41. What is shaft generator
42 how does air compressor start stop automatically
There is a pressure switch provided
which is having a bellow inside which increases & decreases in its size if
the pressure rises to reqd. to start the compressor .
43 Main switchboard safeties.
a. Ebonite Rod.
b. Rubber pad infront of switchboard.
c. Dead-front type switchboard.
d. 0.6 meter gap behind the switchboard.
e. Fuse
f. Circuit Breakers.
g. Earth Fault indicators.
h. Panel doors are earthed.
i. No water, steam or oil pipelines to pass
in its vicinity.
j. Undervoltage Relay
k. Reverse Power trip.
l.
Preferential trip.
m. Overcurrent trip
n. Arc Chute
o. Short-circuit trip.
44. Precautions while connecting shore power?
a. Check terminal box cover
screws/nuts to remove(Find out location), lightly greased & ease up.
45
Why load picked by crane does not fall if power goes off
Because Electro-magnetic brakes get operated.
46. How
electricity is generated.
47.Maintenance on Alternator?
a. Ventilation passages & air filters
to clean.
b. Insulation resistance to check for
Stator, rotor winding. If low, then varnish to be done
c. Air gap to check using plastic feeler
gauge.
d. Bearing oil to be renewed.
e. Use vaccum cleaner to remove dirt/
dust.
f. Terminal box cover gasket integrity to
check.
g. Terminal connections to check for
tightness.
h. AVR components, diodes to keep free
from oil, moisture or any dirt.
i. Heaters to be checked.
48. What is the function of Diode?
The function of a diode is to
allow current in one direction and to block current in the opposite direction.
48. How to carry out Open Circuit & Short circuit test?
Open Circuit Test: The purpose of this
test is to determine no load loss or core loss.
One winding of the transformer, usually
high voltage side if left open and the other is connected to its supply of
normal voltage and frequency. A wattm eter,
voltm eter and the ammeter are
connected in the low voltage winding.
With the normal voltage applied to the
low voltage side, normal flux will be set up in the core, hence normal iron
losses will occur which are recorded by the Wattm eter.
The load current on the low voltage
winding will be small(2 to 5 % of rated full load current ), the copper loss in
the winding will be negligible and will be nil in the high voltage side
winding..
So, the wattm eter
reading will represent practically the core loss under no load condition.
Short-Circuit
Test: This is also known as Impedance test.
In
this test, the low voltage winding is
short circuited by using a thick
conductor (or Ammeter, which serves additional purpose of Indicating Rated load
current).
A
low voltage at correct frequency is applied to the primary and is cautiously
increased till full load current is flowing the high voltage side.
In
this test, the applied voltage is small percentage of its rated value, hence
flux produced is small with the result that iron losses will be negligible and
the Wattm eter reading will represent
the full load Cu-loss.
49. Suppose your motor has short-circuited, then how much value will
you get on Megger.
51.
An example of each.
- Where does magnetic field cuts the
conductor?
-where does conductor cuts the
magnetic field?
52.
How is signal transmitted from Navigational bridge to steering gear?
53.
How is the load decided on AC Compressor & how does it works?
54.
What is Open-circuit & short-circuit in a control unit ?
55.
Safeties in motor?
a. Fuse
b. Overload trip
c. Short-circuit trip
d. Reverse power relay
56. Working principle of Explosimeter?
An explosimeter is a
device which is used to measure the amount of combustible gases present in a
sample. When a percentage of the lower explosive limit (LEL) of
an atm osphere is exceeded, an alarm
signal on the instrument is activated. "Explosimeter"
The
device, also called a combustible gas detector,
operates on the principle of resistance proportional to heat—a wire is heated,
and a sample of the gas is introduced to the hot wire. Combustible gases burn
in the presence of the hot wire, thus increasing the resistance and disturbing
a Wheatstone
bridge, which gives the reading.
A flashback arrestor is installed in the device to avoid
the explosimeter igniting the sample external to the device.
The combustible gas indicator shown
diagrammatically above consists of a Wheatstone bridge with current supplied
from a battery. When the bridge resistances are balanced, no current flows
through the galvanometer. One resistance is a hot filament in a combustion
chamber. An aspirator bulb and flexible tube are used to draw a gas sample into
the chamber. The gas will burn in the presence of the red hot filament causing
the temperature of the filament to rise. Rise of temperature increases the
resistance of the filament and this change of filament unbalances the bridge.
The current flow registers on the meter which is scaled in percentage of LFL or
ppm.
57. Safeties and precautions on portable electrical
equipments?
58. what is the routine maintenance on the starter of main air compressor which is of automatic start stop type?
59. How to test a fuse? -apart from multimeter.
60. Types of Fuses & diagram?
a.
Catridge Type.
b.
HRC(High Rupturing Capacity)
61. Which is the largest induction motor used
onboard?
Alternator
62.
Which current is coming out from Alternator?
63.
How will know proper working of Megger?
64.
Types of Switchboard?
a. Open Type
b. Dead front type.
65.
Whats the use of apparent power(kva) &
reactive power(kvar)??????
Apparent power consists of active and reactive power. Active power
is the share of the apparent power which transmits energy from the source
(generator) to the user. Reactive power is the share of the apparent power
which represents a useless oscillation of energy from the source to the user
and back again
66. What is a
Thyristor?
67. Maintenance
carried out in Stator.
68. Why Star-Delta
starters are used?
69. What all testing
equipment is used for testing an electric motor?
70. Basic meaning of
Intrinsically safe motor?
An
intrinsically safe circuit is one that is designed for a power so low that any
spark or thermal effect produced by it whether there is fault or not, is
incapable of igniting the surrounding gas or vapor.
71. Difference
between Intrisically safe & Explosion proof?
An intrinsically safe circuit is one that
is designed for a power so low that any spark or thermal effect produced by it
whether there is fault or not, is incapable of igniting the surrounding gas or
vapor.
Explosion proof :-
72.Circuit diagram of
Megger?
73.What is the function of Commutator?
74.What is the supply given to shipboard
general alarm.
24 Volt DC.
75.
Maintenance on switchboard?
a. Check contacts of Circuit breaker for damage & dirt.
b. Cleaning of contact using electro-cleaner.
c. Interlocks fitted to check for proper functioning.
- How to make sure
motor is in good condition?
While Running
- No noise
- No vibrations
- Motor frame
temperature normal.
- Current drawn
by the motor is normal.
- No
dirt or dust or no corrosion on fins.
- Drawing rated
current.
During Stop condition.
- Isloate the
system
- Dismantle the
parts
- Check condition
of internal parts, like bearing, fan.
- No damage to
rotor, stator.
- Insulation
resistance to check.
- No signs of
overheating should be there.
While starting
- Developing correct torque & high starting
current.
- Coming back to
its normal rated current in designated time.
76. Draw star, delta
3 phase connections?
77. What are various portable electrical
equipment used?
a.
Megger
b.
Multimeter
c.
Clampmeter
d.
Live line tester.
78. what is the difference between KW and KVA?
KW means that it is the power deliverd to the load. where
as the kva is the power can be meet the load demand. so
that kva is not with respect to load.
- Procedure for
Overhaul of A/E.
a. Check whether all tools and spares are
available or not.
b. If so, then start the Stand by generator.
c. Check all parameters are normal.
d. Now share the load with the help of synchroscope.
e. Again check all the parameters are within
normal range.
f. Put full load on the Stand by generator.
g. Stop the generator on which work has to be
carried out.
h. Put MEN AT WORK
tag.
i. Shut the air starting valve, fuel oil
inlet & outlet valves and isolate the system.
j. Let lube oil priming pump run for half
hour after then stop it.
k. Drain the jacket water.
l. Remove the cylinder head cover.
m. Remove high pressure pipe.
n. Take out the injector using its tool.
o. Open the rocker arm bolts & remove it
from its place.
p. Remove the Jacket water outlet pipe.
q. Disconnect the scavenge & exhaust
manifold from the cylinder head.
r. Open the cylinder head bolts using the
Torque spanner or hydraulic jack(As provided on your vessel).
s. Check the lifting gear (Crane & chain
block, Eye bolt, etc.)
t. Lift the cylinder head & put it at a
suitable place.
u. Open the crankcase door.
v. Bring the piston to TDC position &
attach eye-bolt on it and Attach hook of chain block to it.(Before bringing Piston
to TDC, the top part of liner needs to be cleaned)
w. Bring the piston to BDC and open the
bottom-end bolts & remove bottom end bearing.
x. As load of piston is now on Lifting gear,
so take it out & put it on the piston stand.
y. Remove the piston rings using ring
extractor.
z. Remove the circlip from the gudgeon pin
& take out the gudgeon pin, so connecting rod can be taken out.
- How do you
decide if piston rings should be changed or not?
a. Butt clearance increased then its normal
range.
b. Axial clearance increased.
c. Visual condition of piston ring.
- How you check
lifting gear.
a. Check the
condition of wire rope & grease it.
b. Check the visual
condition of chain.
c. Check the limit
switches in the forward, aft, Port & starboard direction are working.
d. Check that
emergency button is working.
e. Check the visual
condition of the insulated cover is satisfactory.
f. Check overload
trip is working satisfactorily.
g. Check the visual
condition of chain block, no cracks should be there.
h. Check that safety
latch is there on chain block.
- What checks on
piston and liner.
a. Piston:-
i. Check the piston for any
cracks.
ii. Check the piston top
profile.
iii. Check for any carbon
deposits.
iv. Check the butt clearance,
axial & radial clearance.
- What to do if
valve seat damaged?
- Checks on
crankcase inspection in Main Engine?
Safety Precautions:
a.
Inform
bridge and Chief Engineer.
b.
If
in port, take Immobilization certificate.
c.
Get
propeller clearance from the duty officer.
d.
Shut
off starting air valve.
e.
Put
“Men at Work” tag.
f.
Stop
lube oil pump.
g.
Indicator
cocks to open.
h.
Turning
gear should be engaged
i.
Wear
proper PPE, Shoes & helmet.
j.
No
naked lamp to be taken inside.
k.
Open
the crankcase door taking it as a shield.
l.
Ventilate
the crankcase door properly.
m.
No
items should be inside the pockets of boiler suit.
Inspection:
a. Check the condition of lube oil, for any
smell, discoloration, degradation.
b. No
paint parts to be there in the sump.
c. Turn the engine to BDC and under stuffing
box area for any black oil.
d. Check piston rod for any scoring &
roughness.
e. Check piston palm bolts & locking.
f. Check the guide shoes and the area around
it.
g. Check guide shoe end cover bolts.
h. Check X-head bearing general condition.
i. Check all bearing for white metal.
j. Check oil pan area of every unit for any
sludge formations, bearing metals & foreign particles.
k. Check top & bottom of connecting rod
bolts, nuts & locking device.
l. Check the axial movement of bottom end
bearing.
m. Check slippage of web & journal by reference
marks.
n. Check the teeth of transmission gear.
o. Check the tightness of chain drive.
p. Check c/case relief door spring tension,
wire mesh & sealing ring.
q. Check & clear the O.M.D sampling
pipes.
r. Start the lube oil pump & check flow .
s. Check c/case door sealing condition &
close it c/case door.
t. Make sure no foreign matter or tools
should be left inside the c/case.
- Tappet
clearances why plus how to check.
Tappet clearance is
taken to ensure positive closing of the valve & for thermal expansion of
the valve.
Taking all safety
precautions.(See Ans. 1)
Make sure the piston
is on TDC.
i. From the marking on the
flywheel.
ii. From the fuel cam.
iii. Push rod should be free.
Make sure the engine
has cooled down.
Loosen the lock nut
of the rocker arm.
Now adjust the tappet
clearance between the rocker arm & valve stem by tightening or loosing the
nut below the lock nut.
If tappet clearance is less:
i. Valve will open early & close late
ii. Air induced
through inlet valve may leak out. So, less air for combustion.
iii. Power will be
reduced.
iv. Fuel consumption
will increase, engine may become unbalanced, exhaust temp. will be very high.
v. In worst
condition, valve may remain open, resulting in
loss of compression pressure, burning of exhaust valve, T/C fouling will
increase.
If tappet clearance
is more:
i. Valve will open
late & close early.
ii. Lesser heat
energy to T/C, so reduction in scavenge air & hence power.
iii. No proper
removal of gases.
iv. Hammering of
valve stem-may cause damage to valve stem.
- What to check if
Engine is not starting on air and fuel
Engine not starting on Air:-
a. Low air bottle pressure or air line valve
may be shut.
b. Air bottle isolating valve or automatic
valve or distributor not functioning.
c. Control air valves faulty or less control
air pressure.
d. Start air automatic valve jammed.
e. Turning gear engaged.
f. Reversing has not taken place completely.
g. Control valve for fuel or start is not in
it’s end position.
h. Bursting diaphragm on start air line damaged.
i. Fuel lever on maneuvering stand not on
remote mode.
j. Auxiliary blower not running or not on
‘auto’ mode.
k. Emergency stop has activated.
l. Interlock is operated.
m. Cylinder air start valve defective or
sticky.
n. Piston not in firing mode.
Engine not starting on fuel:
a. Less fuel in service tank.
b. Fuel filter is chocked.
c. Fuel supply pumps not delivering required
pressure. Or fuel pump tripped.
d. Fuel level on local maneuvering stand, is
not on remote stand.
e. Fuel rack stuck.
f. Fuel pump malfunctioning, jammed plunger.
g. Injector nozzle needle sticking or holes
blocked.
h. Compression pressure is too low due to
broken piston ring or exhaust valve not closing properly.
i. Fuel pump relief valve leaking.
j. Start air pressure insufficient to turn
the engine fast enough.
- What to check if
Engine is not taking load.
- What precautions
to take to start A/E After overhaul.
a. Water tightness to be checked.
b. Air to be removed from jacket water outlet
line.
c. Priming lube oil pump to run before
starting the engine.
d. Check the lube oil level.
e. Check the flow of lube oil.
f. Blow through the engine before starting.
- How to change
purifier to clarifier.
Remove the gravity disc.
- How to select
damn ring for purifier.
From the monogram provided with manual, which
is drawn with respect to viscosity of oil & which size damn ring to be
used.
If monogram not there, then
a. Chief Engineers experience will come into
use.
b. Hit & trial method to be used.
i.
First use the largest gravity disc and whether oil is overflowing, if so, then
use small size gravity disc and follow this process until oil stops
overflowing.
- What to check if
purifier over flowing.
a. Size of gravity
disc.
b. High throughput.
c. Temperature of the
oil.
- How to stop Aux
Engine if not stopping by stop handle.
a. Pull the fuel rack
to zero position.
b. Operate any trip.
- Charging gas in
Dom Fridge?
a.
Close
the receiver outlet valve and collect the gas in the receiver.
b.
Check
the liquid level, if it is below L/3, Charging is reqd.
c.
Check
the weight of the refrigerant bottle & keep it upright.
d.
Connect
the charging line to the connecting point and keep it loose.
e.
Open
the bottle valve slightly and purge the line into the collecting cylinder and
then tighten the connection.
f.
Open
the charging valve and fully open the bottle valve.
g.
Check
the liquid level in the sight glass and make sure no air bubble present in the
system.
h.
Close
the charging valve and the bottle valve.
i.
Open
the receiver outlet valve & start the compressor.
j.
Carry
out let detector test.
- Charging oil in
Domestic fridge.
Method 1.
a.
Mostly
ships have hand p/p provided which develop more pressure than the inside
pressure.
Method 2.
a.
Reduce
the L.P Cut out setting.
b.
Dip
the pipe inside the c/case of compressor.
c.
Run
compressor, vaccum will develop.
d.
So,
compressor will start sucking the oil.
e.
Make
sure the pipe is diped fully, because it has got chances of sucking air.
f.
If
air gets in, then purge it in a separate bottle after charging of oil gets
completed.
- What to check if
Room temp (one room) not coming down?
-
- What to check if
all room temp not coming down?
-
Room
doors not shut properly.
-
Room
insulation is bad.
-
Air
in system.
-
Room
fans not running.
-
Evaporators
frosted.
-
Compressor
not working satisfactorily, unloader defective, valve leaky, rings damagd.
-
Expansion
valves choked/ malfunctioning.
-
Evaporator
blocked.
- What to do if
dom. fridge is short cycling/
-
L.P
Cut out is defective.
-
L.P
Cut out setting not correct, too low difficult for Cut In.
-
Lesser
gas flow
a.
Less
gas in system.
b.
Drier
Choked.
c.
Expansion
valve filter choked or Expansion valve Malfunction.
d.
Evaporator
Choked.
e.
Compressor
valves leaking.
Actions:-
a.
Check L.P. Cut out setting, Cut out pressure OK.
b.
Check flow of gas by seeing sight glass which should show full flow of
refrigerant.
c.
If no full flow- Either less gas or drier chocked, Clean the drier.
d.
Check level in receiver, if low, then charge gas.
e.
Expansion valve filter choked, then clean it.
f.
Expansion valve malfunctioning- Change it.
g.
Evaporator choked- Blow-thru evaporator with nitrogen.
- Overhaul of
centrifugal pump.
- Changing pipe
join below floor plate without removing pipe.
- Can not pump out
bilges. What checks? What to do if pipe holed?
a.
Check
Sounding of bilge tank.
b.
Check
Bilge tank outlet v/v open or not.
c.
Check
P/p inlet v/v open or not.
d.
Check
p/p working properly.
e.
If
vaccum developing that means hole in pipeline.
If pipe is holed:-
a.
Carry
out Vaccum test by closing inlet valve & opening outlet /v.
b.
If
hole is between the inlet v/v and p/p, vaccum will develop, now remove top of
v/v and put water.
c.
If
hole is in between Inlet v/v and bilge tank outlet v/v, then again put S.W
- Boiler press
coming up and gone above the safety valve lifting pressure. What to do?
Use the easing gear
to release the excess pressure.
- Bridge informs
steering not responding. What to do?
- Air comp bumping
clearance how to check and adjust.
a.
Start
the Stand by compressor.
b.
Stop
the compressor whose bumping clearance has to be taken.
c.
Isolate
the system.
d.
Put
“Men at Work” tag.
e.
Loosen
the cylinder head bolts and lift it.
f.
Measure
the diameter /size of the lead ball.
g.
Bring
piston to TDC and put lead ball on centre of it.
h.
Now,
put the cylinder head and tighten it to required torque.
i.
Now,
again loosen the cylinder head bolt and remove the ball.
j.
Measure
the size of the ball.
k.
The
difference between the initial size and final size is the bumping clearance.
It can be adjusted by either putting a
thinner gasket or putting shim on top half of the bottom end bearing.
- Removal of
broken stud.
First drill the stud little bit & then
use Thread extractor which has left hand thread.
- Bridge informs
lot of smoke from funnel what to do?
a.
Reduce
load on engine.
b.
Check
purifier operating alright/ reduce throughput to have better purification.
c.
Drain
water from settling & service tank.
d.
Check
scavenge air temperature & adjust if reqd. .
e.
Soot
blow the economizer.
f.
Ensure,
fuel oil end heater outlet temperature proper corresponding to attain viscosity
at the point of injection.
g.
Check,
if any particular Exhaust temperature is higher than others, if so, then stop
the engine, Change the injector with a spare overhauled injector.
h.
Check
all fuel pump timings are correct or not.
i.
Dismantle
and carry out overhaul of T/C.
j.
Send
fuel oil for Laboratory analysis.
Reasons:
k.
Improper
combustion.
l.
Burning
of carbon particles collected at EGE.
m.
Overloading
of engine.
- Flooding in
Engine Room what to do?
a.
Inform
bridge & Chief engineer.
b.
Raise
engineers’ call/emergency alarm.
c.
Before
starting bilge pump note down the position of vessel & time of starting.
d.
Other
engineers will in between try to locate the hole or burst of pipe and repair.
e.
If
ingress of water very high, start another pump.
f.
Reduce
the engine r.p.m.
g.
Change
over main s.w suction to emergency bilge suction.
h.
If
level is still coming up try to protect the motor from short-circuiting , if
required start emergency bilge suction valve.
i.
If
situation is not coming in control, prepare lifeboat for lowering.
- What checks to
be made on Aux Engine when running?
Checks:
a.
Check
scavenge air temperature.
b.
Check
Exhaust gas temperature.
c.
Check
r.p.m
d.
Check
load on A/E.
e.
Carry
out peak pressure.
f.
Check
for any abnormal noise or vibration.
g.
Check
jacket water inlet & outlet temperature.
h.
Check
Lube oil temperature & pressure.
- During running
Main Engine stops. What checks?
a.
Check
whether Emergency stop operated by any personnel.
b.
Check
level of fuel oil in Service Tank.
c.
Check
whether purifier working properly.
d.
Check
whether water is there in Service tank due to improper purification.
e.
Low
lube oil pressure trip operated, Check L.O P/p developing correct pressure.
f.
Control
air trip operated, Check control air pressure.
- Boiler blow back
what to do and reasons?
Reasons:-
a.
Insufficient
pre-purging.
b.
Blower
not working.
c.
Accumulation
of oil.
d.
Leaky
solenoid valve.
e.
Dripping
of burner.
Action:-
a.
Stop the firing.
b.
Check
the condition of burner, if it is dripping, then overhaul is required.
c.
Do
the inspection of the furnace.
d.
Carry
out sufficient pre-purging.
e.
Start
the boiler on “Auto” mode.
- Boiler
extinguishes what to do?
a.
Accept
the alarm.
b.
Find
out the reason for extinguishing:-
i.
if
too low water level alarm came, then check pump is developing correct pressure
or not , its is working properly.
ii.
If
Tripped on high pressure, let the steam pressure come down.
iii.
Fuel
oil low pressure alarm , then check functioning of fuel pump, oil in service
tank.
iv.
Fuel
oil low temp. alarm, then use the heater.
v.
Flame
failure trip, then clean flame eye, check the furnace & overhaul the
burner.
- Overhaul of fuel
valve?
Safety Precautions:-
a. Check whether all tools and spares are
available or not.
b. If so, then start the Stand by generator.
c. Check all parameters are normal.
d. Now share the load with the help of
synchroscope.
e. Again check all the parameters are within
normal range.
f. Put full load on the Stand by generator.
g. Stop the generator on which work has to be
carried out.
h. Put MEN AT WORK tag.
i. Shut the air starting valve, fuel oil
inlet & outlet valves and isolate the system.
j. Let lube oil priming pump run for half hour
after then stop it.
k.
Remove the lock nut of the high pressure pipe.
l. Now, remove the high pressure
pipe.
m. Take out the fuel injector using
it tool.
n. Put it on the testing kit.
o. Check the lifting pressure,
atomization, pressure falling steadily, dripping of oil.
p. Now, take out the injector from
the testing kit, put in a diesel oil & clean it.
q. Make sure the workshop table
should be clean, no rags or jute to be there.
r. Put the injector on the vice and
tighten it.
s. Loosen the lock nut of the
injector.
t. Now loosen the compression nut to
release the spring pressure, then take out the spring.
u. Open the cap nut and take out the
needle and guide.
v. Put the parts on the cleaned
table.
w. Check the condition of spring by dropping
on the floor plate, it should jump and also check it by tightening in the vice
and then releasing. The difference in the length,no cracks to be there.
x. Check visually needle, there
shouldn’t be any scoring marks because it is made of Nitrite material.
y. Try to insert the needle inside
the guide at angle of 45degree, the needle should on its own weight.
z. Check the size of injecting holes
by using Go or No go gauge.
i. If go gauge is going then hole
size is OK.
ii. If no go gauge going, then it
means the size has increased, then nozzle needs to be changed.
iii. Now assemble the injector and
do the lifting pressure setting on test kit by adjusting the compression nut.
-iv. After this check the injector
again for its lifting pressure, atomization, steady fall of pressure and
dripping.
- How pressure
testing of Globe Valve is done?
a. Blank one side of valve and put water from
the other side, check for any leakage.
- Overhaul of a
cylinder head & what all to check?
- Overhaul of
Inlet & exhaust valve of aux.enine?
- Function of
Roto-Cap in valves & how it is overhauled?
a. It helps to rotate the valve during
operation with the help of the exhaust gas, so as less wear occurs and stress
doesn’t comes only at one point.
- What is
dye-pentration test, why is it done & how is it done?
Dye-Penetration test is a leak test carried
out to know about the leakage/ crack in any part.
In it, first the part or unit is cleaned,
paint is removed where the crack is suspected, then it marked on the unit. If
water is coming, then colour will change, which shows the crack.
- How alkalinity
test is carried out?
a.
Take
200 ml water sample in the stoppered bottle.
b.
Add
one P.Alkalinity tablet & shake or crush to disintegrate.
c.
If
P.Alkalinity is present the sample will turn blue.
d.
Repeat
the tablet addition, one at a time, until the blue colour turns to permanent
yellow.
e.
Count
the number of tablets used and carry out the calculation:
P.Alkalinity, ppm CaCO3 = (Number of tablet x
20) -10
f.
Record the result obtainied on the log sheet provided, against the date on which result was obtained.
- Why water is
kept heated in hot-well?
a.
To
prevent oxidation
b.
To
avoid thermal stress on boiler.
- Position of
Unloader in AC & Ref. compressor ?
Unloader in AC & Ref. compressor is
located near the suction valve of the compressor.
- What all
clearances taken in centrifugal pump?
a.
The
wear ring & impeller.
b.
The
wear ring & the casing.
c.
Shaft
and the bush.
- Why centrifugal
pump is not self –priming?
Because of the churning effect it is not be
able to remove air positively as mass of air is relatively zero.
- What is the
position of bearing in centrifugal pump?
Near the impeller.
- What is the
position of piston when taking bearing clearances
-
Main
Bearing Clearance --B.D.C
-
Bottom
End bearing clearance—B.D.C
-
Cross-head
bearing clearance.—B.D.C
- How to overhaul gear pump and centrifugal
pump? And clearance to take.
- How to take out connecting road?
- How to test cylinder head relief valve onboard?
- During
maneuvering Bursting disc of air compressor get damaged, what action to
take?
a.
Inform
the bridge about the problem and to give lesser kicks.
b.
Start
the stand by compressor.
c.
Isolate
the compressor whose bursting disc is damaged.
d.
Change
the bursting disc, if available onboard.
e.
If
Not available, then let the S.W go into the E/room bilges, otherwise Fresh
water cooled , then join a flexible hose and put into the expansion tank.
- How will you test the crankcase relief
door?
The testing of the C/case relief door is done
at shore.
- Reasons of
Purifier overflow?
- Procedure for
doing boiler blow down?
Precautions
i.
Ensure
nobody is near the ship side blow down valve.
ii.
Not
to be carried out in drydock or alongside.
iii.
Valve
sequence to be followed.
iv.
Boiler
shouldn’t be left unattended during blow down.
v.
Monitor
the end of blow down. Long blow down to be avoided.
vi.
Don’t
blow down to the E/room bilges.
Procedure
i.
Ship
side valve 1 is opened followed by valve 2.
ii.
Valve
2 is NR which is fully opened to avoid cutting off seat.
iii.
Rate
of blow down controlled by Valve 3.
iv.
For
scum blow down valve 4 & 5 are used.
- Action to be
taken, if chloride content is excess?
Blow down of boiler to be carried out.
- How to blow
through boiler Gauge Glass?
Procedure:
i.
Make
sure drain line is clear
ii.
Close
the steam outlet valve.
iii.
Close
the water outlet valve.
iv.
Open
the drain valve.
v.
Open
the water out valve & let water flow thru it and close the valve after
blowing down with water.
vi.
Open
the steam out valve and blow thru with steam.
vii.
Close
steam valve.
viii.
Close
the drain valve.
ix.
Now,
open the water side valve.
x.
Let
water fill up 3/4th gauge glass.
xi.
Open
the steam valve slowly.
- How to tighten
boiler gauge glass after overhauling?
Procedure of tightening:
i.
First
tighten all the bolts by hand slightly without putting any pressure.
ii.
Now,
tighten bolt 1 & 2 equally. Then 3 & 4.
iii.
Tighten
bolt 5 & 6. then 7 & 8 equally.
iv.
Tighten
bolt 9 & 10.
v.
Now
again tighten 7 & 8. Then 5 & 6.
vi.
Tighten
bolt 3 & 4. then 1 & 2.
Or you can say we first tighten outward bolts
of both side & then inward side.
Then we move in opposite steps. i.e. tight
inward bolts & then outward bolts.
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