Английский язык для моряков / Труханова Англ для моряков
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номинальной как в режиме холостого |
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хода, так и при нагрузке |
differential connection |
встречное включение |
field controller |
регулятор возбуждения |
series motor runs loaded with |
двигатель последовательного |
15-18% of its rated power |
возбуждения нагружен до 15-18% его |
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номинальной мощности |
insufficient loading |
нагружение ниже допустимого |
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предела |
motor runs hot |
перегрев двигателя |
shorted armature |
короткое замыкание в якорных |
coils or pole coils |
катушках или в катушках полюсов |
clogged ventilation |
засорение вентиляционных путей |
channels |
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blow trough |
продуть |
dry compressed air |
сухой сжатый воздух |
tight bearings |
чрезмерная натянутость |
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уплотнительного кольца |
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подшипника |
loosen bearing seal |
ослабить затяжку |
ring |
уплотнительного кольца |
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подшипника |
worn bearing |
износ подшипника |
high or low bars |
выступ или западание |
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коллекторных пластин |
turn |
обточить |
rough commutator |
плохое состояние контактной |
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поверхности коллектора |
1.What are the main faults emerging in D.C. motors?
2.Can you name the reasons owing to which a D.C. motor fails to run? What ;are they?
3.What should you do if the fuse is open?
4.What should you do if the circuit is open?
5.What should you do if the coils are shorted?
6.How do you fight overload?
7.In accordance with what should you connect shunt winding if it has been connected after a starting rheostat?
8.Why does partial shunting of a parallel winding occur?
9.What causes a D.C. motor nominally loaded to run slowly?
10.What should you do if the brushes are set off-neutral?
11.What should you do if the voltage at the motor terminals is either low or high?
12.In what way is it necessary to interconnect the shunt and the series windings in a compound motor?
13.Should you increase or decrease the resistance on the field controller if it is large?
14.What are the reasons why a D.C. motor may run hot?
15.What causes a D.C. motor to be noisy in operation?
16.What should you do if the ventilation channels are clogged?
1.What should you do if the bearings are tight?
2.What should you do if the bearings are worn?
3.What motor element should be put under repair if the bars are either high or low?
4.What should you do if the commutator is rough?
3. TROUBLESHOOTING OF THREE-PHASE MOTORS
FAULT |
CAUSE |
TEST AND REMEDY |
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1. Motor fails |
1. |
Open fuse |
Replace defective fuse with |
to start |
2. |
Defective circuit- |
spare after |
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breaker |
testing on multimeter |
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3. |
One phase winding is |
Repair |
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open when stator winding |
Check voltage at the |
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is star-connected |
terminals of stator winding. |
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4. |
Overload |
If one phase winding is open, |
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5. |
Worn bearings |
eliminate discontinuity. Mind |
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6. |
Two or three rotor |
stator winding. It may be |
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phase windings are open |
open as well Decrease motor |
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(or make poor contact) |
loading Replace with spare |
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7. |
Rotor one-sidedly |
Check for discontinuity or |
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attracted to stator; rotor is |
bad contact and repair where |
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caught in stator |
necessary Check gaps |
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between rotor and stator as |
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well as condition of bearing |
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shells. Also check if end |
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brackets are set correctly |
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2. Motor |
1. |
Low voltage at |
Increase voltage up to rated |
nominally |
terminals of stator |
one or decrease motor |
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loaded runs |
winding |
loading Reconnect to delta |
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slowly (its |
2. |
Stator winding is star- |
Check if the contact is good |
rotational |
connected |
as well as wires connecting |
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speed is low) |
3. |
Large resistance on |
rotor to rheostat are not long |
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phase rotor circuit |
or small-sectioned. Mind |
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4. |
Incorrect |
rheostat. It may be faulty |
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interconnection of stator |
Check connection diagram. |
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phase windings (reversed |
Reconnect to star or delta in |
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phase windings) |
accordance with diagram |
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3. Motor |
1. |
Overload |
See 1.4 See 1.5 |
becomes |
2. |
Worn bearings |
Blow through ventilation |
excessively |
3. |
Clogged ventilation |
channels with dry |
hot |
channels |
compressed air Remove dirt |
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4. |
Clogged air filters |
from air filters Clean air |
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5. |
Clogged water-cooled |
cooler, reduce motor loading |
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air cooler, cooling water |
Re-arrange fen wings or |
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temperature increase |
change direction of rotation |
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6. |
Incorrect rotation of |
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rotor equipped with fan |
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having inclined wings |
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VOCABULARY |
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motor fails to start |
двигатель не |
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разворачивается |
one phase winding is open обрыв цепи одной |
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обмотки фазы |
two or three rotor phase |
обрыв в двух или трех |
windings |
обмотках |
are open |
фаз цепи фазного ротора |
rotor one-sidedly attracted |
одностороннее |
to stator |
притяжение ротора к |
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статору |
rotor is caught in stator |
задевание ротора о статор |
bearing shell |
вкладыш подшипника |
end bracket |
подшипниковый щит |
motor nominally loaded |
двигатель работает с |
runs slowly |
пониженной частотой |
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вращения при |
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номинальной нагрузке |
incorrect interconnection |
неправильное соединение |
of stator |
выводов |
phase windings |
обмоток фаз статора |
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между собой |
reversed phase winding |
одна из обмоток фаз |
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перевернута |
motor becomes |
значительный перегрев |
excessively hot |
двигателя |
clogged air filters |
засорение воздушных |
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фильтров |
remove dirt from air filters очистить воздушные |
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фильтры от rj: |
clogged water-cooled air |
загрязнение |
cooler |
воздухоохладителя с |
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водяным охлаждением |
incorrect rotor rotation |
неправильное вращение |
with fan |
ротора с |
having inclined wings |
вентилятором, имеющим |
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наклонные крылья |
re-arrange |
переставить |
QUESTIONS
1.What are the main faults that can be observed in a three-phase tor?
2.Can you give a list of reasons due to which a three-phase mot fails to start?
3.What should you do if the motor circuit-breaker is defective?
4.How do you test an open phase winding?
5.What should you do if the rotor phase windings are open or m poor contact?
1.Why can the rotor be caught in the stator?
2.What causes a three-phase motor nominally loaded to run slowly?
3.What measures are to be taken to eliminate low voltage at the terminals of the stator winding?
4.What should you check if large resistance is observed on the phase rotor circuit?
5.How do you fight a "reversed phase winding"?
6.What causes a three-phase motor to become excessively hot?
7.What should you do if the ventilation channels are clogged?
8.What do you do to clean air filters?
9.What are the steps recommended to correct the rotor rotation with a fan having inclined wings?
EXERCISES
I. Make sure you've properly understood the texts dealing with troubleshooting of electrical
equipment.
1.Troubleshooting is the procedure of
a)finding a fault;
b)eliminating a fault;
c)both finding and eliminating a fault.
2.Heat and moisture cause:
a)rated current flow;
b)abnormal current flow;
c)minimum current flow.
3.When measuring voltage the electrician must connect the voltmeter:
a)in parallel with the circuit;
b)in antiparallel with the circuit;
c)in series with the circuit.
4. |
When measuring current the electrician must connect the ammeter: |
a) in parallel with the circuit; |
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b) |
in antiparallel with the circuit: |
c) |
in series with the circuit. |
5. |
Before applying an ohmmeter the electrician must: |
a) |
turn on the power; |
b) |
turn off the power; |
c) |
turn down the power. |
6. |
If the fuse is open, you should: |
a) |
rewind it; |
b) |
repair it; |
c) |
replace it |
7. |
If a D.C. motor fails to run, one of the reasons is: |
a)shorted armature circuit;
b)open armature circuit
c)incorrectly connected armature circuit.
8.
a)
b)
c)
9.
a)
b)
c)
If you've found out that the shunt field winding has been incorre ly connected, you should connect it in accordance with:
a factory mark;
a factory wiring diagram factory instructions.
If you've found out that the parallel field winding has been parti ly shunted, you should: connect it to other windings;
connect it to the frame;
disconnect it from both other windings and the frame.
10.If you observe a differential connection of the shunt and the serie windings in a compound motor, you should connect them:
a) in opposition; b) in antiparallel; c) accordantly.
11. If the motor ventilation channels are clogged, you should:
a)blow them trough;
b)remove dirt from them;
c)clean them.
12. If the commutator bars are either high or low, you should:
a)re-arrange the commutator;
b)grind the commutator;
c)set the brushes on neutral.
13. If a three-phase motor fails to start, one of the reasons may be:
a)rotor one-sidedly attracted to the stator;
b)rotor one-sidedly repelled from the stator;
c)rotor one-sidedly fastened to the stator.
14. If you observe large resistance on the phase rotor circuit, the reason may be:
a) a defective circuit-breaker; b) a faulty rheostat;
c) a worn bearing.
15. If the temperature of cooling water in an air cooler increases, you should:
a)blow trough ventilation channels;
b)remove dirt from air filters;
c)clean the air cooler.
16.If a three-phase motor nominally loaded runs slowly, one of the causes is incorrect voltage at the terminals of the stator winding. It is:
a)rated;
b)low;
c)high.
17. If a D.C. motor runs fast, one of the faults is incorrect voltage at the motor terminals. It is:
a)
b)
c)
rated;
low;
high.
18. If you observe tight bearings, you should:
a)tighten a bearing seal ring;
b)loosen a bearing seal ring;
c)replace a bearing seal ring.
II. Choose one of the linking words or word combinations from the box and complete the sentences. Some of them are interchangeable.
not only... but |
in accordance |
since |
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with |
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either... or |
with respect to |
in comparison |
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with |
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on the other |
however |
once |
hand |
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because of |
above all |
as a consequence |
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in the form of |
thus |
by virtue of |
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hence |
than |
owing to |
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1. D.C. machines converting mechanical energy into electrical one are referred to as D.C. generators. Those, __ which convert
electrical energy into mechanical one are called D.C. motors.
2. The series field winding carries the entire armature current and _____ its conductors are of large section.
3.The property __ ___________________________ to which any D.C. machine may work in a motor mode in a generator mode is called convertibility.
4.Series motors while running idle don't tend to overspeed
their shunt field winding.
5. On board ships, ____the work safety rules, only air-cooled
transformers are used.
6. Their efficiency level is higher that of ordinary transformers of the same frequency.
7. This group of connections reveals at what angle line lower voltage is shifted clockwise line upper voltage.
8.Fuses are not mounted _____ if they burn off, the magnetic flux will go up to a dangerous value.
9.The strength of the current in a.c. circuits depends ___
on the resistance of the entire circuit __ _ on the inductance and capacitance of the circuit sections.
10.Transformers measuring current and voltage are designed to widen measurement limits of ammeters, voltmeters etc. ________ they
provide operational safety of these latter.
11.The use of autotransformers is prohibited,, in low voltage
portable lighting. |
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12. |
The flux and the voltage drop in the field winding are both moderate and, |
, the speed of rotation is |
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significant. |
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13. |
With the load increase the current value in the field winding and |
the flux rise. |
14.The frame is made of steel _______ of a closed magnetic conductor.
15.The above mentioned stator winding has only one pair of poles,
_________ which the magnetic field does one revolution during
one cycle of the current reversal.
16. Static converters are used more widely on board ships rotary converters.
17 ._______ the load is increased, the internal voltage drop grows and the speed of rotation drops off.
18. Heat increases the resistance of the circuit anu _____
increases the current.
GLOSSARY
ability |
[a'biliti] |
способность |
abruption |
[э'Ьглр|п] обрыв, разрыв |
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access |
[a'kses] |
доступ |
front |
[fr/vnt] |
с передней стороны |
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(панели) |
on-load ~ |
[on bud] |
под нагрузкой |
rear- |
[ro] |
с задней стороны |
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(панели) |
accessibility |
[ak'sesi'bilit доступность, |
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i] |
досягаемость |
accessible |
[sk'seibl] |
доступный, открытый (о |
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проводке |
accessor/y (-ies)[ak'sesari] |
1) вспомогательная |
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деталь |
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2) (pi) арматура |
cable ~-ies |
[keiblj |
кабельная арматура |
portable ~-y |
ГрэЛэЫ] |
переносная арматура |
wiring—ies |
['waiarig] |
электроустановочные |
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материалы (арматура) |
accommodate |
[a'komadeit размещать, вмещать |
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] |
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accumulate |
[a'kjunnjule накапливать |
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it] |
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accumulation |
[a'kjuimjule накопление |
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ijn] |
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accumulator |
[g'kjumjulei аккумулятор |
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ts] |
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acid- |
['aesid] |
кислотный - |
alkaline - |
['aslkalain] |
щелочной - |
accuracy |
['aekjurasi] |
точность |
action |
['aekjn] |
(воз)действие, эффект |
activate |
f'asktiveit] |
1) возбуждать, ставить |
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под |
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напряжение 2) включать |
adjust |
[3'd3ASt] |
регулировать, |
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настраивать |
adjustable |
[s'd^stsbl] |
регулируемый, |
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настраиваемый |
adj ustable- |
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система генератор |
potential |
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system |
[pa'tenjral] |
- двигатель |
air |
[еэ] |
воздух |
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cooling- |
['ku:liq] |
охлаждающий ~ |
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air-cooled |
[.ea'kuddj |
с воздушным |
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охлаждением |
air-tight |
[^s'taitj |
воздухонепроницаемый |
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airy |
['еэп] |
воздушный |
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alarm |
[э'кпт] |
1) аварийный сигнал |
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2) сигнализация |
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audible - |
[adibl] |
звуковая ~ |
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fire- |
[faia] |
пожарная ~ |
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alteration |
[,D:ltareiJh изменение |
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] |
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alternator |
['orltaneita]генератор переменного |
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тока |
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brushless- |
['brAjIis] |
бесщеточный - |
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synchronous- ['sigkranas]синхронный - |
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amber |
['aemba] |
янтарь, смола |
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ammeter |
['aemita] |
амперметр |
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clam-on- |
['klsem^n] |
токоизмерительный щит |
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amplifier |
['aemplifai |
усилитель |
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a] |
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rotary- |
frautari] |
электромашинный |
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усилитель |
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angle |
Г*ад1] |
угол |
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apparatus |
^aepa'reitasаппарат, прибор, |
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устройство |
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application |
^aepli'keift | исполнение, |
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a^] |
приложение |
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marine - |
[ma'ri:n] |
морское исполнение |
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lire |
[cuk] |
(электрическая) дуга |
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armature |
['amatjua] |
якорь (эл.машины или |
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эл.магнита) |
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attract |
[a'traekt] |
притягиваться |
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automated |
[^ita'meitid автоматизированный |
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] |
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