Английский язык для моряков / Англ Труханова
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3.Why must а workman not rely on fuses, relays and interlock systems?
4.Why is it so important not to remove the grounding prong of а three wire input piug?
5.What does а cluttered bench \ead to?
6.Why is it so necessary for an e!ectrician to work on а rubber mat?
7.Should an electrician work alone or have someone around?
8.Why is it important for an electrician to avoid violent and rapid movements?
EXERCISES
LCl,eckyourselfin your vocabulary. What do уои cal/:
l.the process of taking care of e\ectrical mechanisms on board ship?
2.the actions you fulfi!I when you want to protect yourself?
3.the tools you сап carry from one place to another in your hands?
4.the people who take care of any type of equipment?
5.the things you put on your hands when you want to let yourse\f touch hot-line?
6.the things you put on your feet to protect yourse\f against а расе voltage?
7.the means which ensure your individual protection?
8.the things you put on your face to protect your lungs and skin?
IL Makesureуои haveproperly understoodtlie meaning ofthe text:
l.Electrical traumatism is caused Ьу: а) electrical safety;
Ь) portaЬ\e accessory;
с) formal instructing on safe methods of work.
2.The use of electrica! energy is connected with: а) possiЬ\e fires;
Ь) thermal effect of an electric current; с) environmental conditions.
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3. The normal state of shipboard electrical equipment is broken when: а) you do not put оп special gauntlets;
Ь) insulation can't withstand а working voltage; с) damages occur.
4.When the normal state of shipboard electrical equipment is brok'en: а) clip-on instruments are used;
Ь) protective glasses are put оп;
с) arc and spark discharges emerge.
5.Principal protective means are those which:
а) protect against а расе voltage;
Ь) help to withstand а working voltage; с) are designed for individual protection.
6. Additional protective means are those which:
а) protect against light, thermal and mechanical effects; Ь) protect against the effect of an e\ectric arc;
с) make it possiЬ\e to touch hot-Iine parts.
III.Mind the grammatical construction о/Present Simple Passive.
1.Add the Past Participle to the following sentences taken from the text. Choosefrom the verbs in the Ьох. Use each verb опсе оп/у:
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design |
rate |
associate |
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observe |
calculate |
break |
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1) |
The heating of conductors and current \eading parts |
of the e\ec |
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trical equipment is |
. . . so that it not exceed fixed |
rates. |
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2) |
Additional protective means are not |
. . . to ensure protection |
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from electric shock hazard. |
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3)Under normal conditions а thermal effect of an electric current is
4)If the Rules of e\ectrica\ maintenance and safety are not . . . , the
normal state of the equipment is . . .
5) The use of electrica\ energy is not only injury of an operating personnel.
2. Put the verb in the correctform using Present Simp/e Active or Present Simple Passive:
l) If the Rules of shipboard |
electrical maintenance and safety |
(not observe), if damages |
(occur) and the environmental |
conditions . . . (affect) the electrical equipment, its normal state
. . . (break). 2) Isolating gloves
means.
3) Insulating rubber rugs of an electric arc.
4) Insulation of principal protective means working voltage of an electrical set.
5) Тhе operating personnel of an electrical set may insulating galoshes.
3. Trans/ate into English using either positive or negative forms of Imperative:
1)Убедитесь в том, что оборудование исправно.
2)Никогда не убирайте заземляющий штырь трехфазного вход ного штепселя.
3)Всегда двигайтесь медленно, когда работаете в окружении электрических цепей.
4)Ни с кем не разговаривайте во время работы.
5)Не работайте в одиночку.
6)Попытайтесь вспомнить правила эксплуатации электрообору дования и техники безопасности.
7)Никогда не работайте на мокром полу.
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UNIT 10
TROUBLESHOOTING
1. TROUBLESHOOTING OF ELECTRICAL COMPONENTS
The causes for e\ectrica\ equipment to breakdown are heat, mois ture, ingress ofdirt and other contaminants, vibration, and poor installation.
Heat increases the resistance ofthe circuit and thus increases the cuпent causing the material to expand, dry out, crack, and wear down
much quicker. Sooner or \ater the device will Ье broken.
Moisture a\so causes circuit to draw more cuпent and eventually breakdown. Moisture like water and liquids causes expansion, warping
ofthe material as wel\ as abnormal cuпent flow or short circuit.
Dirt and other contaminants are fumes, vapours, grease, oils 
etc. They cause electrical device to clog or gum up and operate abnormally
until breakdown.
Vibration andpoor installation сап a\so cause the above mentioned types ofbreakdown soon.
The breakdown causes \isted аЬоvе result in а number ofdetrimental effects involving ореп circuit, short circuit, grounded circuit and me chanical breakdowns. These \atter are often а result oftoo much fтic
tion, wear or vibration which moving parts like broken belts, worn con tacts, worn bearings, loose be\ts etc. cause.
Неге are some basic methods used in trouЬ\eshooting electrical or e\ectronic devices.
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1.Voltage measurement of а circuit, which is usually taken Ьу us ing а voltmeter. The electrician must always connect а voltmeter in par a)lel with the circuit when measuring voltage.
2.Amperage measurement of а circuit, which is usually taken Ьу using an ammeter or а clam-on ammeter that locates common circuit faults, such as short, open or grounded circuits. The electrician must always connect an ammeter in series with the circuit when measuring current.
3.Resistance measurement, with which an ohmmeter is used to mea sure the continuity of а circuit or а component. The electrician must re member to shut offthe power before using an ohmmeter.
4.Substitution, which is а technique of replacing а suspected faulty component with а good spare one.
. 5. Bridging is employed when an electrician suspects а component like а capacitor to Ье faulty and places а good component across а sus
pected faulty one &от the ircuit.
. Other methods of trouЫeshooting are those of heating, &eezing,
using testers, resoldering, adjusting, by-passing etc. They are all effec- |
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. . :·, . . |
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tive in locating faults of every component in а circuit. |
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VOCABULARY |
trouЫeshooting |
нахождение и устранение неисправностей |
ingress |
проникновение |
contaminant |
загрязняющее вещество |
expand |
расширяться |
dry out |
высыхать |
crack |
трескаться |
warping |
коробление, деформация |
vapour |
пар, испарение |
fume |
ДЫМ |
grease |
жир |
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clog |
засоряться |
gum up |
склеиваться |
grounded circuit |
заземленная цепь |
clam-on ammeter |
токоизмерительные клещи |
substitution |
замена |
bridging |
соединение по мостовой схеме |
freezing |
замораживание |
resoldering |
перепайка |
by-passing |
шунтирование |
QUESTIONS
1. What are the causes for electrical equipment. to breakdown?
2.Why does heat cause the material to expand; dry out, crack and wear down?
3.What does moisture cause?
4.Do you know any contaminants? What are they?
5.What are detrimental effects that are caused Ьу heat, moisture, dirt, vibration?
6.What are mechanical breakdowns caused Ьу?
7.What way of connecting а voltmeter does the electrician necessari ly use when measuring voltage?
8.What way of connecting an ammeter does the electrician necessari ly use when measuring current?
9.What is а clam-on ammeter used for?
10.What must the electrician remember to shut off before measuring resistance?
11.What kind of technique is substitution?
12.What method is called bridging?
13.What are other methods used in trouЫeshooting electrical devices?
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2. TROUBLESHOOTING OF D.C. MOTORS
FAULT |
CAUSE |
TEST AND REMEDY |
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1. Motor fails \о run |
1. Open fuse |
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Replace defective fuse with spare |
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with its |
armature |
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after testing оп mullimeter |
supplied |
Ьу rated |
2. Open starting rheostat |
Check rheostal for disconnection and |
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voltage |
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repair where necessary |
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З. Open armature circuit |
Check armature winding for discon· |
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nection. Replace discontinued sec- |
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tion, remove bad pieces of soldering |
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4. Shorted coils of shunt fleld winding |
Replace defective coils |
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5. Open field circuil |
(or field circuit |
Check field winding for disconnection |
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makes bad contact) |
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and repair where necessary |
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6. Over1oad |
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Remove over1oad |
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7. lncorrect conneclion of shunt |
Connect shunt winding in accordance |
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field winding (connected after start- |
with factory wiring diagram |
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ing rheostat) |
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8. Partially shunted parallel winding |
Check if parallel winding is connect- |
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ed to other windings or frame. Dis- |
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connect il from these latter |
2. Motor nominally |
1. Over1oad |
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See 1.6 |
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loaded runs slowty |
2. Low voltage at motor temiinals |
Supply molor terminals with rated |
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(its rotalional speed |
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vol\age |
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is lower than rated |
з. Brushes set |
off-neutral |
Set brushes оп neutral. Make use of |
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one |
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(in direction of motor rotation) |
а factory mark the brush-rocker саг- |
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ries |
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4. Shorted amiature circuit |
Examine armature coils for signs of |
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burning. Replace defective coils |
з. Motor idle or |
1. Brushes set off-neutral (in di- |
See 2.3 |
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loaded runs fast (its |
rection reversing motor rotation) |
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rotational speed is |
2. Differential connection in а com- |
Connecl shunt and series windings |
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higher lhan rated |
pound motor |
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accordanlly |
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one) |
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з. Large resistance оп field con- |
Decrease resistance |
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troller |
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4. Series motor runs loaded |
Find and eliminate the cause of in- |
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with15-18%of its rated power |
sufficient loading |
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5. High voltage at motor terminals |
See 2.2 |
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4. Motor runs hot |
1. Over1oad |
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See 1.6 |
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2. Shor1ed armature coils or pole Repair or replace defective coils |
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coils |
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З. Short circuil belween field windEliminate short circuit |
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ing coils of commutating poles |
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4. Clogged ventilation channels |
Blow trough ventilation channels with |
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dry compressed air |
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5. Тight bearings |
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Loosen bearing seal ring |
5. Motor is noisy in 1. Wom bearings |
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Replace with spare |
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operation |
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2. High or tow bars |
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Tum commulalor |
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З. Rough commulalor |
See 5.2 |
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VOCABULARY
motor fails to run with its armature supplied Ьу rated voltage
open fuse
open starting rheostat open armature circuit shorted coil disconnection discontinued section
remove bad pieces of soldering remove overload
incorrect connection factory wiring diagram
partially shunted parallel winding
frame
motor nominally loaded runs slowly
brushes set off-neutral
factory mark
in direction of motor rotation in direction reversing
motor idle or loaded runs fast
differential connection field controller
series motor runs loaded with 15-18% of its rated power
insufficient loading motor runs hot shorted armature
coils or pole coils
двигатель не вращается, хотя к его якорю подведено номинальное напряжение
перегорание предохранителя обрыв в пусковом реостаrе обрыв в обмотке якоря короткое замыкание в катушке обрыв секция с обрывом
устранить плохие пайки
снять перегрузку
неправильное включение заводская схема частичное шунтирование
параллельной обмотки возбуждения корпус при работе двигателя с номинальной
нагрузкой частота вращения ниже номинальной
смещение щеток с геометрической нейтрали
заводская метка по направлению вращения двигателя
против направления частота вращения двигателя выше
номинальной как в режиме холостого хода, так и при нагрузке
встречное включение регулятор возбуждения двигатель последовательного
возбуждения нагружен до 15-18% его номинальной мощности
нагружение ниже допустимого предела перегрев двигателя короткое замыкание в якорных
катушках или в катушках полюсов
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clogged ventilation channels |
засорение веmиляционных пуrей |
Ыowtrough |
продуть |
dry compressed air |
сухой сжагый воздух |
tight bearings |
чрезмерная нагянуrость уплотнительного |
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кольца подшипника |
loosen bearing seal ring · |
ослабить загяжку уплотнительного |
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кольца подшипника |
wom bearing |
износ подшипника |
high or low bars |
выступ или западание коллекторных пластин |
tum |
обточить |
rough commutator |
плохое состояние котактной |
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поверхности коллектора |
QUESТIONS
1.What are the main faults emerging in d.c. motors?
2.Сап you name the reasons owing to which а 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 а starting rheostat?
8.Why does partial shunting of а parallel winding occur?
9.What causes а d.c. motor nominally Ioaded to run slowly?
1О. What should you do if the brushes are set off-neutral?
11. What should you do ifthe voltage at the motor terminals is either low or high?
12.ln what way is it necessary to interconnect the shunt and the series windings in а compound motor?
13.Should you increase or decrease the resistance on the field controller
if it is large?
14.What are the reasons why а d.c. motor may run hot?
15.What causes а d.c. motor to Ье noisy in operation?
16.What should you do if the ventilation channels are clogged?
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17.What should you do if the bearings are tight?
18.What should you do if the bearings are wom?
19.What motor element should Ье put under repair if the bars are either high or low?
20.What should you do if the commutator is rough?
З. TROUBLESHOOTING OF THREE-PHASE MOTORS
FAULT
1.Мotorfails to start
1
CAUSE |
TEST AND REMEDY |
1. Openfuse |
Replace defectivefuse with spare after |
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testing оп multimeter |
2. Defectivedn:uit-breaker |
Repair |
3. One phasewinding is open v.hen |
Check voltage at the temiinals ofstator |
statorwinding is star-<:0nnected |
winding. lf one phase winding is open, |
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eliminate discontinuity. Mind statorwind- |
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ing. lt may Ье open as well |
4.0ver1oad |
Decrease motor loading |
5. Wom Ьearings |
Replace with spare |
6. Twoorthreerotorphasewindings |
Check for discontinuity or bad contact |
are open (or make poor rontact) |
and repair where neoessary |
7. Rotor one-sidedly attracted to |
Check gaps Ьetween rotor and stator as |
statoг, rotor is caught in stator |
well as rondition of Ьearing shells. Also |
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check ifend brackels are set correctly |
2. Мotor nominally loaded runs skmfy (its rotational speed is low)
1
1
1. |
Low voltage at temiinals ofstalncrease voltage up to rated опе or de- |
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torwinding |
crease motor loading |
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2. |
Stator winding is star-connect- |
Reronnect to delta |
ed |
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3. |
Large resistance оп phase roCheck ifthe rontact is good as well as |
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tordrcuit |
wires oonnecting rotor to rheostat are not |
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long or small-sectioned. Мind rheostat lt |
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may Ье faulty |
4. lnrorтect interronnection ofstaCheck oonnection diagram. Reronnect to tor phase windings (reversed star or delta in aorordancewith diagram phase v.indings)
з. Моюr Ьeromes |
1.0ver1oad |
See 1.4 |
exc:essively hot |
2. Wom Ьearings |
See 1.5 |
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3. Clogged ventilation channels |
Blow through ventilation channels |
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with dry compressed air |
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4. Clogged airfilters |
Renюve dirt from air filters |
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5. Clogged water-cooled air oooler, |
Clean air oooler, reduce motor loading |
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cooling water temperature increase |
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6. lncorтect rotation сА rotor equipped |
Re-arrange fan v.ings or change diredion |
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with fan having indinedwings |
ofrotation |
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