Published On: Sun, Jun 19th, 2022

© Electrical machines through practical questions and answers – Part 2

Author: Radoje Jankovic.

II.BASIC KNOWLEDGE OF ELECTRICAL MENGINES, DEFINITIONS AND IMAGES

1.Make a comparison: alternator-transformer-asynchronous electric motor!

These are the three types of the most important electric machines that allow us to get rid of hard work, especially today in the modern technological environment. Power plant with alternators – generators is a source of electricity, ie. electricity, which is adjusted to economically justified transmissionby means of transformers for raising the voltage to the voltage level for energy transmission, most often to high voltage overhead power lines of different voltage levels, even up to 750 kV to certain areas and regions, ie. to end consumers, both individual and group, with many installed asynchronous electric motors from the lowest to the highest power, converting electric current into mechanical work to start a variety of devices, from the smallest to the largest.

An asynchronous electric motor is usually three-phase, and less often single-phase, while an asynchronous generator is used very rarely. Therefore, under the term asynchronous electric machine, we usually mean three-phase asynchronous electric motor.

2. Which electric machine is most used today? The asynchronous (induction) electric motor is mostly used. Asynchronous electric motors have many different constructions and shapes. There are also some modern modifications that are conditional on modern technology of electric motor drives.

The asynchronous electric motor is of simple construction, it is cheap, it is easy to start, and it is safe to drive.

Asynchronous electric motors are also called induction electric motors because the energy from the stator to the rotor is transmitted electromagnetically, thanks to Nikola Tesla, a three-phase rotating magnetic field is needed. In 1889, the Russian MO Dolivo-Dobrovolski constructed an asynchronous electric motor with a short-circuited cage on the rotor.


Slika 2.1. Nikola Tesla, pronalazač asinhronog elektromotora
Figure 2.1. Nikola Tesla, inventor of the asynchronous electric moto

3. Uporedite asinhroni elektromotor i transformator!

Asinhroni, odnosno indukcioni elektromotor sličan je transformatoru kod koga se

energija prenosi sa primara na sekundar pomoću elektromagnetne indukcije bez

galvanski provodljive veze.

Kod asinhronog elektromotora primarni namotaj nalazi se na statoru, a spaja se

na trofaznu električnu mrežu. Iz statora se energija prenosi elektromagntnom

indukcijom preko vazdušnog prostora u sekundarni deo odnosno rotor, na kome

se nalazi bilo normalan namotaj izveden na klizne prstenove (armature sa

prstenovima ili (bakarni) štapovi koji su međusobno spojeni čeonim kratkospojen

im prstenovima, te se naziva kavezni rotor. Rotor bi se obrtao i kada bi bop

izrađen samo od masivnog gvožđa ili drugog metala, ali takvo rešenje ne bi bilo

ekonomski opravdano. Setimo se aluminijumskog diska kod indukcionog

električnog brojila.

Kod transformatora bio on trofazni ili jednofazni oba namotaja su čvrsto

namotana na jzgru, pa se ne mogu javljati privlačne ili odbojne sile, odnosno

pomeraji između njih kod normalnog opterećenja. Kod motora mora se međutim,

jedan deo obrtati. Zbog toga je gvozdeno jezgro motora podeljeno na nepomični

deo – stator i na pokretni deo – rotor. Između njih mora postojati vazdušni postor,

kako bi se rotor mogao slobodno okretati.

3. Compare an asynchronous electric motor and a transformer!

An asynchronous or induction electric motor is similar to a transformer in which energy is transferred from the primary to the secondary by means of electromagnetic induction without galvanically conductive connections.

In an asynchronous electric motor, the primary winding is located on the stator and is connected to a three-phase electrical network. From the stator, energy is transferred by electromagnetic induction through the air space to the secondary part, ie the rotor, on which there is a normal winding made of sliding rings (fittings withrings or (copper) rods which are interconnected by end-to-end short-circuited rings, and are called cage rotors. The rotor would rotate even if it were made only of solid iron or other metal, but such a solution would not be economically justified. We remember the aluminum disk in the induction electric meter.

In the case of transformers, whether three-phase or single-phase, both windings are tightly wound on the core, so there can be no attractive or repulsive forces, ie displacements between them at normal load. In thecase of motor engines, however, one part must rotate. Due to that, the iron core of the motor is divided into fixed ones part – stator and the moving part – rotor. There must be an air gap between them, so that the rotor can rotate freely.


Slika 3.1. Šematski presek trofaznog asinhronog elektromotora
Figure 3.1. Schematic cross section of a three-phase asynchronous electric motor

Šematski  presek trofaznog asinhronog elektromotora vidimo prikazan na slici 3.1.

sa trofaznim namotajom na statoru i sa kratkospojenim rotorom. Trofazna struja

u statoru proizvodi obrtno magnetno polje koje preseca provodnike u rotorskom

namotaju i u njima indukuje napon. Pošto je rotorski namotaj kratkospojen,

indukovani napon će u njemu izazvati struju. Na provodnike rotora kroz koje 

prolazi struja sada deluje obrtno magnetno polje mehaničkim silom I rotor počinje

da se obrće. Brzina obrtanja se povećava sve dok se ne ustali na određenu

vrednost koja zavisi od opterećenja. Rotor asinhronog elektromotora ne postiže

nikada onu brzinu kojom rotira obrtno magnetno polje  i to zato jer se u rotoru

kod te brzine (sinhrone) ne bi ništa indukovalo, ne bi tekla struja i ne bi bilo sile.

Zbog toga se ovaj elektromotor i  naziva asinhronim.

Schematic cross-section of a three-phase asynchronous electric motor is

shown in Figure 3.1. with three-phase winding on the stator and with

short-circuited rotor. The three-phase current in the stator produces a

rotating magnetic field that intersects the conductors in the rotor winding

and induces voltage in them. Since the rotor winding is short-circuited, the

induced voltage will cause current in it. A rotating magnetic field now acts on

the rotor conductors through which the current passes with a mechanical

force and the rotor begins to rotate. The speed of rotation is increased until

it reaches a certain value that depends on the load. The rotor of the

asynchronous electric motor does not reach never the speed at which the

rotating magnetic field rotates, and that is because nothing would be

induced in the rotor at that speed (synchronous), no current would flow and

there would be no force. That is why this electric motor is called

synchronous.

4. Opišite ukratko, šematski presek asinhronog elektromotora sa slike 3.1.

Provodnici u žlebovima statora U1, U2 pripadaju fazi L1, provodnici V1, V2 fazi L2, a W1, W2 fazi L3. Svaki namotaj na statoru stvara dva pola nepomičnog magnetnog polja, tako da na taj način zajedno stvaraju dovpolno obrtno magnetno polje. Maksimalna struja u smeru prema nama pomera se od provodnika 1, 1, 1 faze U na 3’, 3’, 3’ faze V i dalje faze W na 1’, 1’, 1’ itd. U rotoru se indukuje struja čije magnetno polje stvara reakciju obrtnom magnetnom polju statora i na taj se način privlače i rotor se okreće za magnetnim poljem statora. Tako pojednostavljeni indukcioni motor predstavlja neku vrstu transformatora sa vazdušnim rasporom.

4. Briefly describe the schematic section of the asynchronous electric motor from Figure 3.1.

Conductors in stator grooves U1, U2 belong to phase L1, conductors V1, B2 to phase L2, and W1, W2 to phase L3. Each winding on the stator creates two poles of a fixed magnetic field, so that together they create a fully rotating magnetic field. The maximum current in the direction towards us moves from conductors 1, 1, 1 of phase U to 3 ‘, 3’, 3 ‘of phase B and further of phase W to 1′, 1 ‘, 1’, etc. A current is induced in the rotor whose magnetic field reacts to the rotating magnetic field of the stator and is thus attracted and the rotor rotates behind the magnetic field of the stator.Such a simplified induction motor is a kind of transformer with an air gap.

5. Od kojih konstrukcionih delova se sastoji asinhroni electromotor?

5. What are the structural parts of an asynchronous electric motor?

According to the principle of operation of the asynchronous electric motor from Figure 3.1, it can be seen that

Shodno principu rada asinhronog elektromotora sa slike 3.1, se vidi da se

asinhroni elektromotor sastoji od statora i rotora na koje se umeću statorski i rotorski namotaj.

Na donjim slikama prikazali smo uzdužne preseke nekoliko tipova električnih rotacionih mašina, koje prikazuju osnovne konstruktivne i aktivne delove električnih mašina, njihov međusobni raspored i funkcionalnu povezanost.

Naravno, danas postoji mnogo konstruktivnih oblika električnih mašina, posebno kod mikro, minijaturnih, malih, srednjih i velikih mašina snage od više megavata, za male napone od nekoliko volti do desetinu volti, niske napone do 1000 V ivisoke napone od nekoliko desetina kilovolti.

5. What are the structural parts of an asynchronous electric motor?

According to the principle of operation of the asynchronous electric motor from Figure 3.1, it can be seen that  an asynchronous electric motor consists of a stator and a rotor on which a stator and rotor winding are inserted.

In the pictures below we have shown the longitudinal sections of several types of electric rotary machines, which show the basic structural and active parts electrical machines, their mutual arrangement and functional connection. Of course, today there are many  constructive forms of electric machines, especially for micro, miniature, small, medium and large machines of several megawatts, for low voltages from a few volts to ten volts, low voltages up to 1000 V and high voltages of several tens of kilovolts.


Slika 5.1. Tipičan pojednostavljen montažni crtež trofaznog asinhronog
elektromotora sa namotatin rotorom i kliznim prstenovima za 380 V,
mehanička zaštita IP 44, oblik IM B3, hlađenje IC 0141.
Figure 5.1. Typical simplified assembly drawing of a three-phase
asynchronous electric motor with winding rotor and sliding rings for 380 V,
mechanical protection IP 44, form IM B3, cooling IC 0141.

1-statorski paket limova

2-rotorski paket limova

3-kućište statora

4-valjkasti ležaj

5-spoljašnji poklopac ležaja

6-unutrašnji poklopac ležaja

7-štit ležaja

8-rotorski namotaj

9-statorski namotaj

10-karika sa navojem za podizanje motora

11-unutrašnji ventilator

12-kuglični ležaj

13-kapa ventilatora

14-spoljašnji ventilator

15-zavrtanj za držače četkica

16-klizni kolutovi-prstenovi

17-priključna kutija

18-poklopac priključne kutije

19-kablovski uvodnik statora

20-kablovski uvodnik rotora

1-stator sheet metal package

2-rotor sheet metal package

3-stator housing

4-roller bearing

5-outer bearing cover

6-inner bearing cover

7-bearing shield

8-rotor winding

9-stator winding

10-link with thread for lifting the motor

11-internal fan

12-ball bearing

13-fan cap

14-external fan

15-screw for brush holders

16-slip rings-rings

17-terminal box

18-terminal box cover

19-cable stator inlet

20-cable rotor inlet

Na slici 5.1.1, 5.1.2. Prikazano je nekoliko konstruktivnih rešenja kliznih prstenova trofaznog asinhronog elektromotra sa namotanim rotorom. 

Na slici 5.1.3. Prikazan je jedan sklop četvorostrukih klizni prstenova za posebne konstrukcije elektromotora.

In Figures 5.1.1, 5.1.2. Several constructive solutions of sliding rings of a three-phase asynchronous electric motor with a wound rotor are presented.

In Figure 5.1.3. One set of quadruple sliding rings for special constructions of electric motors is presented.


Slika 5.1.1. Izgled nekoliko konstruktivnih rešenja kliznih prstenova za kliznokolutne trofazne elektromotore
Figure 5.1.1. Appearance of several constructive solutions of sliding rings for sliding three-phase electric motors

Slika 5.1.2 Još različitih konstruktivnih rešenja kliznih prstenova za trofazne kliznokolutne elektromotore sa namotanim rotorom
Figure 5.1.2 More different design solutions of sliding rings for three-phase sliding-disc electric motors with wound rotor

Slika 5.1.3. Prikaz jednog sklopa četvorostrukih klizni prstenova za posebne konstrukcije elektromotora
Figure 5.1.3. Demonstration of one set of quadruple sliding rings for special constructions of electric motors

Slika 5.2. Tipičan pojednostavljen montažni crtež trofaznog asinhronog
elektromotora sa kratkospojenim-kaveznim rotorom 380 V, mehaničke zaštite IP
44, oblik IM B3, hlađenje IC 0141.
Figure 5.2. Typical simplified assembly drawing of a three-phase
asynchronous electric motor with short-circuited-cage rotor 380 V,
mechanical protection IP 44, form IM B3, cooling IC 0141.

1-statorski paket limova

2-rotorski paket limova

3-kućište statora

4-valjkasti ležaj

5-spoljašnji poklopac ležaja

6-unutrašnji poklopac ležaja

7-štit ležaja, pogonska strana motora

8-rotorski namotaj

9-statorski namotaj

10-karika za podizanje motora

11-kapa ventilatora

12-spoljašnji ventilator

13-štit ležaja, suprotna strana motora

14-priključna kutija motora

15-poklopac priključne kutije

16-uvodnik za kabl 

1-stator sheet metal package

2-rotor sheet metal package

3-stator housing

4-roller bearing

5-outer bearing cover

6-inner bearing cover

7-bearing shield, motor drive side

8-rotor winding

9-stator winding

10-motor lifting link

11-fan cap

12-external fan

13-bearing shield, opposite side of the motor

14-terminal motor box

15-terminal box cover

16-cable entry


Slika 5.3. Tipičan pojednostavljen montažni crtež trofaznog asinhronog
elektromotora u protiveksplozionoj zaštiti “neprodorni oklop”,  6000 V,
mehaničke zaštite IP 44 (priključna kutija IP54), oblik IM B3, hlađenje IC
0151.
Figure 5.3. Typical simplified assembly drawing of a three-phase
asynchronous electric motor in explosion protection “impenetrable armor”,
6000 V, mechanical protection IP 44 (terminal box IP54), form IM B3, cooling
IC 0151.

1-statorski paket limova

2-rotorski paket liova

3-kućište statora

4-valjkasti ležaj

5-odvodna ploča

6-spoljašnji poklopac ležaja

7-unutrašnji poklopac ležaja

8-unutrašnji ventilator

9-štit ležaja, pogonska strana motora

10-rotorski namotaj

11-statorski namotaj

12-zaslon

13-uređaj za podmazivanje ležaja

14-poklopac ventilatora

15-spoljašnji ventilator

16-štit ležaja, suprotna stana motora

17-zavrtanj za pričvršćivanje ventilatora

18-kuglični ležaj

19-priključna kutija motora

20-kablovski zaglavak

1-stator sheet metal package

2-rotor sheet metal package

3-stator housing

4-roller bearing

5-drain plate

6-outer bearing cover

7-inner bearing cover

8-inner fan

9-bearing shield, drive side

10-rotor winding

11-stator winding

12-screen

13-bearing lubrication device

14-fan cover

15-external fan

16-bearing shield, opposite motor housing

17-screw for fixing the fan

18-ball bearing

19-terminal motor box

20-cable header


Slika 5.4. Tipičan pojednostavljen montažni crtež elektromotora jednosmerne
struje  380 V, mehaničke zaštite IP 23, oblik IM B3, hlađenje IC 01.
Figure 5.4. Typical simplified assembly drawing of 380 V DC electric motor,
mechanical protection IP 23, shape IM B3, cooling IC 01.

1-glavni polovi

2-pomoćni polovi

3-armatura tj. rotor

4-kućište statora

5-valjkasti ležaj

6-spoljašnji poklopac ležaja

7-unutrašnji poklopac ležaja

6-štit ležaja

9-unutrašnji ventilator

10-namotaj rotora tj. armature

11-namotaj glavnih polova

12-karika za rukovanje elektromotorom

13-uvodnik za kabl

14-namtaj pomoćnih polova

15-priključna kutija motora

16-poklopac priključne kutije

17-četkice

18-kolektor (komutator)

19-držač četkica

20-priključni zavrtnjevi

21-nosač držača četkica

22-kuglični ležaj

23-poklopac (žaluzine) ulaznog i izlaznog otvora rashladnog vazduha

1-main poles

2-auxiliary poles

3-fittings, ie. rotor

4-stator housing

5-roller bearing

6-outer bearing cover

7-inner bearing cover

6-bearing shield

9-inner fan

10-rotor winding, ie. armature

11-coil main poles

12-link electric motor

13-cable entry

14-pin auxiliary poles

15-terminal motor box

16-cover terminal box

17-brush

18-collector (switch)

19-brush holder

20-connection screws

 21-brush holder bracket

22-ball bearing

23-cover (blinds) cooling air inlet and outlet openings


Slika 5.5. Tipičan pojednostavljen montažni crtež sinhronog samopobudnog
generator (motora) 400 V, mehaničke zaštite IP 21, oblik IM B3, hlađenje IC 01.
Figure 5.5. Typical simplified assembly drawing of a synchronous self-
excitation generator (motor) 400 V, mechanical protection IP 21, shape IM
B3, cooling IC 01.

 1-statorski polovi

2-rotorski paket limova

3-kućište statora

4-poklopac izlaznog otvora rashladnog vazduha

5-valjkasti ležaj

6-spoljašnji poklopac ležaja

7-unutrašnji poklopac ležaja

8-ležajni štit

9-unutrašnji ventilator

10-rotorski namotaj

11-namotaj statorskih polova

12-zavrtanjska karika za rukovanje generatorom

13-zavrtnjevi za učvršćenje statorskih polovađ

14-uvodnici za kablove

15-priključna kutija

16-poklopac priključne kutije

17-priključni bolcnovi (svornjaci)

18-pobudni sklop

19-balansni prsten

20-kuglični ležaj

21-klizni prstenovi (koluti)

22-poklopac ulaznog otvora rashladnog vazduha

23-zavrtanj za uzemljenje.

1-stator poles

2-rotor sheet package

3-stator housing

4-cover cooling air outlet cover

5-roller bearing

6-outer bearing cover

7-inner bearing cover

8-bearing shield 9-internal fan

10-rotor winding

11-stator pole winding

12-screw generator control link

13-bolts for fixing stator halves

14-cable glands

15-terminal box

16-terminal box cover

17-bolt connection bolts)

18-actuator assembly

19-balance ring

20-ball bearing

21-slip rings

22-coolant air inlet cover

23-earthing screw.


Slika 5.6. Identifikujte sve delove ovog trofaznog asinhronog elektromotora i
napišite njihove nazive.
Figure 5.6. Identify all parts of this three-phase asynchronous electric motor
and write their names.

Slika 5.7. Izgled jednog tipičnog viskonaponskog dizel električnog agregata velike
snage
Figure 5.7. Appearance of a typical high-power high-voltage diesel electric
generator

6. Kućište statora i zaštitnici (štitovi)!

Kućište statora i spoljašnji zaštni poklopci ležajeva su konstrkcioni delovi

električnih mašina svih tipova i konstrukcionih  oblika. Na gore prikazanih nekoliko ilustracija prikazano je samo nekoliko ovih konstruktivnih delova. Inače, kod električnih mašina koje se danas proizvode (kao i kod starijih električnih mašina koje su i danas u upotrebi)  postoji mnoštvo različitih izvedbi kućišta statora i ležajnih štitova, u zavisnosti od vrste i veličine električne mašine njenoj mehaničkoj zaštiti i od načina hlađenja iste. 

Kućište statora

je konstruktivni deo električne mašine mašine koje služi za učvršćivanje jednog ili više statorskih jezgara (paket limova ili masivni polovi.

Krajni ili štit ležaja (ležajni štit)

je puni ili šuplji konstruktivni deo pričvršćen za kućište statora, koji služi za zaštitu namotaja i u koji može biti ugrađen ležaj.

Slika 6.1. prikazuje dva oblika kućišta asinhronih elektromotora malih snaga. Ova kućišta su izrađena postupkom livenja aluminijumske legure (silumin) u odgovarajućim alatima. Kućišta statora srednjih električnih mašina izrađuju se od livenog gvoža (sivi liv). Kućišta velikih električnih mašina se rade od čeličnih limova i profila sa uzdužnim i poprečnim rebrima i mogu biti veoma komplikovane konstrukcije, što ćete videti u ovoj seriji napisa o električnim rotacionim mašinama.

6. Stator housing and protectors (shields)!

The stator housing and the outer protective covers of the bearings are structural parts of electrical machines of all types and construction shapes. In the few illustrations shown above, only a few of these constructive parts are shown. By the way, with electric machines that are produced today (as well as with older electric machines that are still in use today), there are many different designs of stator housings and bearing shields, depending on the type and size of the electric machine and its mechanical protection.

Stator housing

is a structural part of an electrical machine that serves to secure one or

multiple stator cores (sheet metal package or solid poles.

End or bearing shield (bearing shield)

is a solid or hollow structural part attached to the stator housing, which serves to protect the windings and in which the bearing can be installed.

Figure 6.1. shows two forms of low-power asynchronous electric motor housings. These housings are made by casting aluminum alloy (silumin) in appropriate tools. The stator housings of medium electric machines are made of cast iron (gray cast iron). The housings of large electric machines are made of steel sheets and profiles with longitudinal and transverse ribs and can be very complicated constructions, which you will see in this series of articles about electric rotary machines.


Slika 6.1. Slika prikazuje dva oblika kućišta statora niskonaponskih asinhronih
Elektromotora sa površinskim hlađenjem. (a) za oblik motora IM B3; (b) za oblik
motora IM B5.
Figure 6.1. The figure shows two shapes of the stator housing of low-voltage
asynchronous electric motors with surface cooling. (a) for motor design IM
B3; (b) for motor shape IM B5.

Slika 6.2. Izgled jednog livenog kućišta statora trofaznog elektromotora
Figure 6.2. Appearance of one cast stator housing of a three-phase electric
motor

Slika 6.3. Liveno kućište trofaznog asinhronog elektromotora od aluminijumske 
legure sa rebrima za spoljašnje hlađenje elektromotra.
Figure 6.3. Cast aluminum three-phase asynchronous electric motor housing
with fins for external cooling

Slika 6.4. Izgled još jednog livenog kućišta trofaznog asinhronog elektromotora od
aluminijumske  legure sa rebrima za spoljašnje hlađenje elektromotra.
Figure 6.4. Appearance of another cast housing of a three-phase
asynchronous electric motor made of aluminum alloy with fins for external
cooling of the electric motor.


Slika 6.5. Ležajni štitovi ili kako se u praksi još zovu, prednji i zadnji poklopci
asinhronih elektromotora koji potpuno zatvaraju stator motora. (a) za oblik
motora IM B3; (b) za oblik motora IM B5.
Figure 6.5. Bearing shields or as they are called in practice, front and rear
covers of asynchronous electric motors that completely close the stator of
the motor. (a) for motor design IM B3; (b) for motor shape IM B5.

Slika 6.6. Izgled livenih ležajnih štitova (poklopaca) jednog asinhronog
elektromotora
Figure 6.6. Appearance of cast bearing shields (covers) of an asynchronous
electric motor

Slika 6.7. Čišćenje ležišta ležaja u ležajnim štitovima asinhronog elektromotora
Figure 6.7. Cleaning the bearing housing in the bearing shields of an
asynchronous electric motor

7. Hlađenje električnih rotacionih mašina!

Hlađenje rotacionih električnih mašina definisano je IEC standardima koji

obuhvataju različite načine strujanja rashladnog sredstva i dovođenja energije za

strujanje rashladnog sredstva. 

Neke IEC definicije osnovnih elemenata ventilacionih sistema kod električnih

mašina su:

Ventilator

je konstrukcioni element koji tera rashladno stredstvo.

Ventilatorska kapa

je konstruktvni element koji okružuje ventilator i stvara stvara spoljašnju granicu

gasa (vazduha) koji tera ventilator.

Ventilacioni kanali u paketu limova

su prostori između deonih paketa limova ili u njima predviđeni za prolaz radijalne

ili aksijalne struje rashladnog gasa.

Vazdušni kanal

je kanal u donjem delu mašine ili u temlju za dovod hladnog ili odvod zagrejanog

vazduha mašine.

Ventilacioni kanal

je kanal za vođenje rashladnog vazduha.

Ventilacioni sklop površinski hlađenih električnih mašina sastoji se od ventilatora I

ventilatorske kape, kako je prikazano na slici 7.1.

Ventilatori malih motora i ventilatorske kape, vidi sliku 7.2. izrađuju se od

plastičnog materijala. Za temperature okoline iznad 60⁰ C kao i za motore s

otpornim karakteristikama treba koristiti metalne ventilatore i ventilatorske od

čeličnog lima ili silumina.

Na slici 7.4 prikazani su izgled i dimenzije jednog malog plastičnog ventilatora sa dvanaest radijalnih krilaca.

7. Cooling of electric rotary machines!

Cooling of rotary electrical machines is defined by IEC standards that include different ways of refrigerant flow and supply of energy for refrigerant flow.

Some IEC definitions of the basic elements of ventilation systems in electrical machines are:

-Fan

is a structural element that forces the coolant.

-Fan cap

is a structural element that surrounds the fan and creates an external boundary of gas (air) that drives the fan.

-Ventilation ducts in the sheet metal package

are the spaces between the partial packs of sheets or in them provided for the passage of radial or axial current of the cooling gas.

-Air duct

is a channel in the lower part of the machine or in the base for the supply of cold or exhaust of heated air of the machine.

-Ventilation duct

is a channel for conducting cooling air.

The ventilation assembly of surface-cooled electrical machines consists of a fan and a fan cap, as shown in Figure 7.1.

Small motor fans and fan caps, see Figure 7.2. they are made of plastic material. For ambient temperatures above 60⁰ C as well as for motors with resistant characteristics, metal fans and fans made of sheet steel or silumin should be used.

Figure 7.4 shows the appearance and dimensions of a small plastic fan with twelve radial blades.


Slika 7.1. Principijeni prikaz ventilacionog sklopa površinski hlađenih električnih
mašina
Figure 7.1. Principal representation of the ventilation assembly of surface-
cooled electrical machines

Slika 7.2. izgled jednog plastičnog ventilatora koji se primenjuje kod malih
asinhronih elektromotora
Figure 7.2. the appearance of a single plastic fan used in small asynchronous
electric motors

Slika 7.3. Ventilator kapastog tipa (kapa ventilator) koji se primenjuje kod
niskonaponskih asinhronih elektromotora, npr. kaveznog tipa.
Figure 7.3. Cap-type fan (fan cap) used in low-voltage asynchronous electric
motors, e.g. cage type.

Slika 7.4. Izgled ventilator i kape ventilatora jednot trofaznog asinhrohronog
motora koji je bio pogonu dugo bez adekvatnog održavanja
Figure 7.4. Appearance of the fan and fan caps of one three-phase
asynchronous motor that has been in operation for a long time without
adequate maintenance 

Slika 7.5. Izgled jednog trofaznog asinhronog elektromotora posle pravilnog
servisisranja sa očišćenim i ponovo ofarbanim ventilatorskim poklopcem
Figure 7.5. Appearance of a three-phase asynchronous electric motor after
proper servicing with cleaned and repainted fan cover
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Slika 7.6. Jedan mali jednofazni kolektorski motor za ugradnju u električne aparate
sa plastičnim ventilatorom za hlađenje
Figure 7.6. One small single-phase collector motor for installation in electrical
appliances with a plastic cooling fan

Slika 7.7. Još jedan tip malog univerzalnog jednofaznog elektromotora za ugradnju
u električne uređaje i aparate sa ventilatorom za hlađenje
Figure 7.7. Another type of small universal single-phase electric motor for
installation in electrical appliances and devices with a cooling fan

Slika 7.8. Kućište statora trofaznog asinhronog elektromotora snage 315 kW, 6000
V, 50 Hz sa cevastim kanalima za hlađenje spoljašnjim vazduhom.
Figure 7.8. Stator housing for three-phase asynchronous electric motor
power 315 kW, 6000 V, 50 Hz with tubular ducts for outdoor air cooling.
Figure 7.9a.

Slika 7.9a. i 7.9b. Izgled i dimenzije jednog malog plastičnog ventilatora sa dvanaest radijalnih krilaca
Figure 7.9a. and 7.9b. Appearance and dimensions of a small plastic fan with twelve radial wings

Slika 7.10. Izgled jednog plastičnog ventilatora za hlađenje elektromotora sa 9 krilaca
Figure 7.10. Appearance of one plastic fan for cooling an electric motor with 9 blades

Slika 7.11. Plastični ventilator za hlađenje elektromotora, ugrađen na zadnji kraj motora prikazanog na slici
Figure 7.11. Plastic fan for cooling the electric motor, installed at the rear end of the motor shown in the figure
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Slika 7.12. Mali elektromotor sa Hal senzorom sa ventilatorom za hlađenje.
Figure 7.12. Small electric motor with Hall sensor and with cooling fan.

Slika 7.13. Elektromotor veće snage sa posebno montiranim ventilatorom za
hlađenje elektromotora
Figure 7.13. Higher power electric motor with specially mounted electric
motor cooling fan

Slika 7.14. Elektromotor velike snage sa sistemom sa prinudnom cirkulacijom
rashladnog sredstva, montiranog na gornjoj strain elektromotora
Figure 7.14. High power electric motor with forced circulation system of the
refrigerant, mounted on the upper side of the electric motor

Slika 7.15. Veliki visokonaponski elektromotor sa posebnim ventilacionim
sistemom u sklopu same konstrukcije elektromotora
Figure 7.15. Large high-voltage electric motor with a special ventilation
system within the construction of the electric motor

Slika 7.16. Još jedan visokonaponski elektromotor sa prigrađenim sistemom za
prinudno hlađenje. Sa slike vidimo da je sistem za hlađenje ovog elektromotora
po dimenzijama veći od samog motora
Figure 7.16. Another high-voltage electric motor with a built-in forced
cooling system. From the picture we can see that the cooling system of this
electric motor dimensionally is almost larger than the motor itself

-Načini strujanja rashladnog sredstva (prvi broj u oznaci)

0-Mašine sa slobodnim ulazom i izlazom vazduha

1-Mašine sa cevnim priključkom, ulazni kanal

2-Mašine sa cevnim priključkom, izlazni kanal

3-Mašine sa cevnim priključkom, ulazni i izlazni kanal

4-Površinski hlađene mašine, rashladno sredstvo je okolni vazduh

5-Mašine sa ugrađenim izmenjivačem toplote, (npr. cevni izmenjivač) rashladno

sredstvo je okolni vazduh

6-Mašine sa prigrađenim izmenjivačem toplote, rashladno sredstvo je okoloni

vazduh

7-Mašine sa ugrađenim izmenjivačem toplote, rashladno sredstvo nije okolni vazduh

8-Mašine sa prigrađenim izmenjivačem toplote, rashladno sredstvo nije okolni vazduh

9-Mašine sa odvojeno postavljenim izmenjivačem toplote

-Načini dovođenja energije za strujanje rashladnog sredstva (drugi broj u oznaci)

0-Prirodno (samo) hlađenje

1-Sopstveno hlađenje

2-Sopstveno hlađenje pomoću uređaja za ventilaciju koji nije postavljen na osovinu mašne

3-Strano hlađenje pomoću uređaja za ventilaciju ugrađenog u mašini, rad zavisaan od rada mašine

5-Strano hlađenje pomoću uređaja za ventilaciju ugrađenog na mašinu, rad nezavisan  od rada mašine

6-Strano hlađenje pomoću uređaja za ventilaciju prigrađenog na mašinu, rad nezavisan od rada mašine

7-Strano hlađenje pomoću odvojeno postavljenog uređaja za ventilaciju ili pomoću vazduha pod pritiskom iz mreže za snabdevanje

8-Hlađenje usled relativnog pokretanja (pomicanja) (npr. strujanjem vazduha pri vožnji)

-Ways of refrigerant flow (first number in the label)

0-Machines with free inlet and outlet air

1-Machines with pipe connection, inlet channel

2-Machines with pipe connection, outlet channel

3-Outside cooling by means of a ventilation device installed in the machine, operation dependent on the operation of the machine

4-Surface cooled machines, the refrigerant is ambient air

5-Machines with built-in heat exchanger, (eg tube exchanger) refrigerant is ambient air

6-Outside cooling by means of a ventilation device mounted on the machine, operation independent of the operation of the machine

7-Side cooling by means of a separate ventilation device or by means of compressed air from the supply network

8-Cooling due to relative starting (moving) (eg driving air flow)

-Methods of energy supply for refrigerant flow (second number in the label)

0-Natural (self) cooling

1-Self cooling

2-Self-cooling by means of a ventilation device not mounted on the shaft of the bow

3-Side cooling by means of a ventilation device installed in the machine, operation dependent on the operation of the machine

5-Side cooling by means of a ventilation device installed on the machine, operation independent of the operation of the machine

6-Side cooling by means of a ventilation device mounted on the machine, operation independent of the operation of the machine

7-Side cooling by means of a separate ventilation device or by means of compressed air from the supply network8-Cooling due to relative starting (moving) (eg driving air flow)

8. Priključci i priključni elementi električnih mašina!

Priklljučci i priključni elementi su veoma važni kod električnih mašina.  Pri proizvodnji i premotavanju rotacionih električnih mašina posebna se pažnja posvećuje pravilnoj izradi izvoda sa namotaja i piključnih stezaljki jer se na taj način znatno doprinosi kvalitetu elektromotornog pogona i sigurnosti osoblja.

Veća oštećenja električnih mašina često počinju preskakanjem električne iskre ili dovoda zbog slabo ili loše dimenzionisanih priključnih stezaljki. Izvodi električnih mašina međusobno se znatno azlikuju zavisno o vrsti i veličini električne mašine.

Prema IEC standardima, definicije osnovnih elemenata i priključaka električne mašine bi bile sledeće:

 Stezaljka

je provodni deo namotaja namenjen za spajanje sa spoljnom električnom mrežom.

Priključni sklop

je sklop predviđen za stvaranje spoja između stezaljki električne mašine i spoljašnje mreže iz koje se ista napaja, niski ili visoki napon.

Priključni svornjaci (bolcnovi sa navojom)

su vrsta priključka pri kojem stezaljke imaju oblik svornjaka trajno pričvršćenih na kućište ili sklop električne mašine.

Priključna letvica ili pločica

je vrsta priključka pri kojem su stezaljke letvice trajno pričvršćene na kućište ili sklop električne mašine.  

Stezaljka za uzemljenje

je stezaljka pričvršćena na dostupnim metalnim delovima mašine, koji u slučaju kvara mogu biti napajani strujom, i predviđena za spajanje sa provodnikom za uzemljenje. 

Slobodni krajevi namotaja

su vrsta priključka, pri kojem su stezaljke neučvršćeni provodnici (kablovi).

Priključna kutija

je vrsta priključnog sklopa u kojem su stezaljke spojene s vodovima za napajanje unutar kutije koja zatvara spojeve pri čemu su zadržane minimalne potrebne dimenzije za odgovarajući pristup i preglednost kao i za puzne staze. Kutija ima pomični poklopac da bi se pristupilo spojevima u njoj.

8. Connections and connecting elements of electrical machines!

Connectors and connecting elements are very important in electrical machines. During the production and rewinding of rotary electric machines, special attention is paid to the proper production of windings and turnbuckles, because in this way it significantly contributes to the quality of electric motor drive and staff safety.

Major damage to electrical machines often begins by skipping an electric spark or supply due to poorly or poorly dimensioned connection terminals.

The leads of electric machines differ significantly depending on the type and size of the electric machine. According to IEC standards, the definitions of the basic elements and connections of an electrical machine would be as follows:

-Terminal

is a conductive part of the winding intended for connection to the external electrical network.

-Connection assembly

is an assembly designed to create a connection between the terminals of an electrical machine and the external network from which it is supplied, low or high voltage.

-Connection bolts (bolted bolts)

are a type of connection in which the clamps have the shape of bolts permanently attached to the housing or assembly of an electrical machine.

-Connecting strip or plate

is a type of connection in which the batten clamps are permanently attached to the housing or assembly of an electrical machine.

-Earthing terminal or clamp

is a clamp attached to accessible metal parts of the machine, which in the event of a fault can be supplied with electricity, and provided for connection to a grounding conductor.

-Free ends of windings

are a type of connection, in which the terminals are unsecured conductors (cables).

-Terminal box

is a type of terminal assembly in which the terminals are connected to the supply lines inside the box which closes the joints while retaining the minimum necessary dimensions for proper access and visibility as well as for creep paths. The box has a sliding lid to access the joints in it.







Figure 8.1. Appearance of the connection ends from the stator windings,
which are to be connected to the terminals mounted on the terminal board
of the electric motor in the terminal box                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

Slika 8.1. Izgled priključnih krajeva sa namotaja statora, koje treba povezati na stezaljke koje su montirane na priključnoj pločici elektromotora u priključnoj kutiji.               

Figure 8.1. Appearance of the connection ends from the stator windings, which are to be connected to the terminals mounted on the terminal board of the electric motor in the terminal box  


Slika 8.2. Stezaljka (zavrtanj) za uzemljenje na stopi elektromotora (označen
crvenom bojom spojen žutozelinm zaštitnim provodnikom (provodnikom za
uzemljenje) sa metalnom konstrukcijom na kojoj je motniran electromotor.
Zavrtanj na čeličnoj konstrukciji je elektrolučno zavaren za konstrukciju zbog
boljeg spoja sa velikom čeličnom konstrukcijom.
Figure 8.2. Clamp (screw) for grounding at the foot of the electric motor (marked in red) connected by a yellow-green protective conductor (grounding conductor) to the metal structure on which the electric motor is mounted. The screw on the steel structure is arc welded to the structure due to better connection with main metal structure.

Slika 8.2a. Postolje, nosač trofaznog elektromotora je poseban mašinski deo koji
je za veliku čeličnu konstrukciju pričvršćen pomoću visokokvalitetnih čeličnih
zavrtnjeva, što se vidi na slici (ovde se radi o jednoj od više gusenica za transport 
velikog bagera. Stezaljka (zavrtanj) za uzemljenje na stopi elektromotora (desno
gore) spojena je žutozelinm zaštitnim provodnikom (provodnikom za uzemljenje)
sa metalnim postoljem elektromotora pomoću čeličnog zavrtnja koji je zavaren na
postolje (detalj se jasno vidi u sredini slike). Drugi žutozeleni provodnik za
uzemljenje spojen je sa glavnom čeličnom kontrukcijom u ovom slučaju velikog
guseničnog transporta jednog bagera  konstrukcijom na kojoj je motniran
electromotor.
Zavrtanj na čeličnoj konstrukciji je elektrolučno zavaren za konstrukciju zbog
boljeg spoja sa velikom čeličnom konstrukcijom.
 
Figure 8.2a. The base, the support of the three-phase electric motor is a
special machine part that is attached to a large steel structure with high-
quality steel screws, as shown in the picture (top right) is connected by a
yellow-green protective conductor (earthing conductor) with a metal base of
the electric motor by means of a steel screw welded to the base (the detail is
clearly visible in the middle of the picture). The second yellow-green earthing
conductor is connected to the main steel structure in this case a large
caterpillar transport of one excavator by a structure on which the electric
motor is mounted.
The screw on the steel structure is arc welded to the structure due to better
connection with main metal structure.
 

9. Priključne kutije rotacionih električnih mašina!

Kao što znamo priklljučna kutija je deo električne mašine u kojoj su na posebnoj

priključnoj pločici izvedeni krajevi sa statorskih i rotorskih namotaja. S napretkom

tehnologije izrade električnih rotacionih mašina tekao je razvoj i usavršavanje

priključnih kutija. Neke konstrukcije priključnih kutija iz prakse prikazane su na

donjim slikama.

U praksi se koriste dve vrste priključnih kutija:

  1. Priključne kutije za niskonaponske elektromotore i
  2. Priključne kutije za visokonaponske elektromotore.

9. Connecting boxes of rotary electric machines!

As we know, the terminal box is a part of an electrical machine in which the ends of the stator and rotor windings are made on a special terminal board. With the advancement of the technology of making electric rotary machines, the development and improvement of junction boxes took place. Some constructions of junction boxes from practice are shown in the figures below.

In practice, two types of junction boxes are used:

A) Terminal boxes for low voltage electric motors and

B) Terminal boxes for high voltage electric motors.

  1. PRIKLJUČNE KUTIJE ZA NISKONAPONSKE ELEKTROMOTORE

Za niskonaponske elektromotore priključne kutije su standardizovane, mada ih u praksi ima i nestandardizovani, koje se rade po posebnim zahtevima.

Kod većine niskonaponskih elektromotora priključna kutija smeštena je na desnoj strani motora, gledano s pogonske strane. Priključnu kutiju moguće je skoro uvek smestiti i na levu stranu motora, ali je to potrebno prilikom naručivanja elektromotora zahtevati od proizvođača. Kod mnogih elektromotora može se priključna kutija premestiti na suprotnu staanu zakretanjem kućišta motora. Takođe je moguće zakretanje priključne kutije za 90⁰ i 180⁰ od njenog normalnog položaja. Razmaci i puzne staze u priključnoj kutiji dobro su dimenzionisani korišćenjem prostornog rasporeda i upotrebom normalnih delova.

Izgledi priključnih kutija različitih konstrukcija prikazani su na slikama 9.1., 9.2., 9.3., 9.4., 9.4a. i 9.5. sa kućištima motora.

A. CONNECTION BOXES FOR LOW VOLTAGE ELECTRIC MOTORS

For low-voltage electric motors, junction boxes are standardized, although in practice there are also non-standard ones, which are made according to special requirements. For most low-voltage electric motors, the terminal box is located on the right side of the motor, viewed from the drive side. The terminal box can almost always be placed on the left side of the motor, but this is necessary when ordering electric motor required from the manufacturer. With many electric motors, the terminal box can be moved to the opposite position by turning the motor housing. It is also possible to rotate the terminal box 90 and 180 from its normal position. The distances and creep paths in the terminal box are well dimensioned using the spatial layout and the use of normal parts.

Layouts of junction boxes of different constructions are shown in Figures 9.1., 9.2., 9.3., 9.4., 9.4a. and 9.5. with motor housings.


Slika 9.1. Priključna kutija trofaznog elektromotora izlivena zajedno sa kućištem
Figure 9.1. Terminal box of three-phase electric motor cast together with housing

Slika 9.2. Skoro kvadratna priključna kutija elektromotora izrađena zajedno sa
livenjem kućišta statora.
Figure 9.2. Almost square terminal box of the electric motor made together
with the casting of the stator housing

Slika 9.3. Pravougaona priključna kutija elektromotora izrađena zajedno sa
livenjem kućišta statora, otvorima za kablovske uvodnike na dužim stranama.
Figure 9.3. Rectangular terminal box for electric motors made together with
stator housing casting, openings for cable glands on longer sides

Slika 9.4. Liveno kućište statora elektromotora zajedno sa priključnom kutijom. Sa
leve strane se vidi poklopac kutije a sa gornje strane zaštitni poklopci motora.
Figure 9.4. Cast stator housing for electric motor together with terminal box. The cover of the box can be seen on the left side and the protective covers of the motor on the upper side.

Slika 9.4a. Pogled na priključnu kutiju elektromotora koja je izlivena zajedno sa
kućištem statora iz jednog dela. Na dve rupe sa navojem pričvršćuje se priključna
pločica motora, u donjem levom uglu je otvor za zavrtanj za priključak zaštitnog
provodnika-uzemljenja, na levoj stranici kutije vidi se otvor za kablovski uvodnik i
ispred njega na dnu pravougaoni otvor za prolaz faznih krajeva sa statorskih
namotaja koji se učvršćuju na stezaljke priključne pločice.
 
Figure 9.4a. View of the terminal box of the electric motor which is cast
together with the stator housing from one part. The motor connection plate
is attached to two threaded holes, in the lower left corner there is a screw
hole for the protective conductor-earthing connection, on the left side of the
box you can see the cable entry hole and in front of it at the bottom a
rectangular hole for static windings which are fastened to the terminal screws
on the terminal board

Slika 9.5. Na ovoj slici se vidi sklapanje motora sa statorom s prethodne dve slike.
Figure 9.5. This picture shows the assembly of the stator motor from the previous two pictures.  

Na slikama 9.6, 9.7., 9.8. i 9.9. prikazani su izgledi priključnih kutija sa priključnom pločicom.

In Figures 9.6, 9.7., 9.8. and 9.9. the layout of the terminal boxes with the terminal board is shown.


Slika 9.6. Pravougaona priključna pločica trofaznog asinhronog elektromotora. Na
slici vidimo da je namotaj motora spojen u trougao
Figure 9.6. Rectangular connection plate for three-phase asynchronous
electric motor. In the picture we see that the motor winding is connected in a
triangle

Slika 9.7. Priključna kutija sa priključnom pločicom jedno jednofaznog
elektromotora
Figure 9.7. Terminal box with single-phase electric motor connection plate

Slika 9.8. Priključna kutija sa tri kablovska uvodnika od kojih su dva iskorišćena.
Figure 9.8. Terminal box with three cable glands, two of which are used.

Slika 9.9. Levi stator elektromotora je bez priključne kutije, desni stator je sa priključnom kutijamom u kojoj si izvedeni krajvi faznih namotaja motora
Figure 9.9. The left stator of the electric motor is without a terminal box, the right stator is with a terminal box in which the ends of the phase windings of the motor are made.

Slika 9.9a. Visokonaponski  kliznokolutni elektromotor, 6 kV, 315 kW  sa tri priključne kutije; levo za senzore u namotajima, u sredini priklučak na visoki napon a desno za priključak rotorskih otpornika.
Figure 9.9a. High voltage slip-ring electric motor, 6 kV, 315 kW with three terminal boxes; left for sensors in windings, high voltage connection in the middle and right for connection of rotor resistors

Slika 9.9b. Niskonaponski asinhroni elektromotora sa priklučnom kutijom na gornjoj strani motora.
Figure 9.9b. Low voltage asynchronous electric motor with terminal box on the top of the motor.

Slika 9.9c.  Viskonaponski aisnhroni elektromotora sa priključnom kutijom na gornjoj strani motora
Figure 9.9c. High voltage asynchronous electric motor with terminal box on the top of the motor

Slika 9.9d. Visokonaponski elektromotora sa vertikalno montiranom priključnom kutijom sa desne strane
Figure 9.9d. High voltage electric motor with vertically mounted terminal box on the right side
Slika 9.9e. Visokonaponski trofazni kratkospojeni elektromotora za transport nafte (shipping oil motor)
Figure 9.9e. High voltage three-phase short-circuited rotor shipping oil motor

Slika 9.9f. Niskonaponski elektromotor sa priključnom kutijom na gornjoj strani elektromotora a uvodnik za kablove pod uglom
Figure 9.9f. Low voltage electric motor with terminal box on the upper side of the electric motor and cable gland at an angle

Slika 9.9g. Priključna kutija na gornjoj strani jednog visokonaponskog elektromotora sa uvodnikom za kablove pod uglom
Figure 9.9g. Terminal box on the top of a high-voltage electric motor with angled cable gland

Slika 9.9h. Priključna kutija motora levo, desno kutija za zaštitne elemente montirane na gornjoj strani motora
Figure 9.9h. Motor terminal box on the left, box on the right for the safety elements mounted on the top of the motor

Slika 9.9i. Priključne kutije jednog niskonaponskog asinhronog elektromotora sa strane pod nagibnim uglom
Figure 9.9i. Terminal boxes of one low-voltage asynchronous electric motor on the side at an inclined angle

Slika 9.9j. Dvodelna priključna kutija na gornjoj strani jednog asinhronog elektromotora
Figure 9.9j. Two-part junction box on the top of one asynchronous electric motor

Slika 9.9k. Priključna kutija na gornjoj strani elektromotora na strani do pogonske osovine
Figure 9.9k. Terminal box on the top of the electric motor on the side next to the drive shaft

Slika 9.9l. High voltage 4160 VAC, 60 Hz cage asynhronous electric motor fo oil shipping

Pravougaone prikljućne pločice sa 6 priključnih svornjaka (navojnih bolcnova) su standardizovane, a izrađuju se od visokokvalitetnog izolacionog materijala. Polnopreklopivi elektromotori imaju 6, 9 ili 12 stezaljki. Normalne priključne kutije su potpuno zatvorene, mehanička zaštita je IP 44 ili IP 54, a imaju jedan, dva, tri ili više otvora sa uvodnicima za priključak, što se vidi na donjim slikama.

Ponekada se električni priključci sa statorskih namotaja izvode samo sa jednožilnim kablovima kao slobodni, bez posebnih priključnih svornjaka (bolcnova sa navojem), npr. motori za ventilacione kanale, dubinske pumpe, vučni motori – trakcijski motori i za slične namene što se vidi na slici 9.5.    Mali i ugradni elektromotori takođe se najčešće proizvode bez priključne pločice i kutije, samo sa izvedenim krajevima sa jednožilnim provodnicima, kako bi se štedeo prostor aparata u koji se isti ugrađuju. Primeri takvih elektromotora prikazani su na Slika 9.10a., 9.10b., 9.10c., 9.10d., 9.10e., 9.10f.,9.10g. i 9.10h.

Jednofazni elektromotori za opštu namenu opremljeni su najčešće sa kablom koji na kraju ima šuko utičnicu ili kombinaciju utikač-prekidač.

Rectangular connection plates with 6 connection bolts (threaded bolts) are standardized and are made of high quality insulating material. Pole

changeable electric motors have 6, 9 or 12 terminals. Normal terminal boxes are completely closed, the mechanical protection is IP 44 or IP 54, and they have one, two, three or more openings with connection glands, as seen in the pictures below.

Sometimes electrical connections from stator windings are made only with single-core cables as free, without special connection bolts (threaded bolts), e.g. motors for ventilation ducts, submersible pumps, traction motors and for similar purposes as shown in Figure 9.5.

Small and built-in electric motors are also usually produced without a connection plate and boxes, only with derived ends with single-core conductors, in order to save space of the apparatus in which they are installed. Examples of such electric motors are shown in Figure 9.10a., 9.10b., 9.10c., 9.10d., 9.10e., 9.10f., 9.10g. and 9.10h. Single-phase electric motors for general purpose are usually equipped with a cable that eventually has a shucko socket or a plug-switch combination.


Slika 9.10a. Neki proizvođači na svoje elektromotore ne ugrađuju priključne kutije,
već izvodne provodnike sa faznih namotaja statora izvode ka slobodne sa
kablovskim stopicama na provodnicima.
Figure 9.10a. Some manufacturers do not install terminal boxes on their
electric motors, but run the output conductors from the stator phase
windings to the free ones with cable lugs on the conductors.

Slika 9.10b. Izgled još jednog eleketromotora bez priključne kutije, već samo sa
slobodno izvedenim izolovanih priključnih finožičanih provodnika.
 Figure 9.10b. The appearance of another electric motor without a terminal
box, but only with freely made insulated connecting fine-wire conductors.

Slika 9.10c. Mali motor sa izvodima od izolovanih finožičanih provodnika različite boje
Figure 9.10c. Small motor with leads made of insulated fine wire conductors of different colors

Slika 9. 10d. Minijaturni motor sa finožičanim provodnicima kao izvodima za
priključak na napon.
Figure 9. 10d. Miniature motor with fine-wire conductors as terminals for
voltage connection.

Slika 9.10e. Mikro motor sa izolovanim provodnicima za priključenje na napon.
Figure 9.10e. Micro motor with insulated conductors for voltage connection.

Slika 9.10f. Mali jednofazni motor za ugradnju u aparate sa izvodima od
finožičanih izolovanih provodnika
Figure 9.10f. Small single-phase motor for installation in appliances with
terminals made of fine-wire insulated conductors
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Slika 9.10g. Jedan mali elektromotor bez priključne kutije za ugradnju u električne
aparate
Figure 9.10g. One small electric motor without terminal box for mounting into
electrical appliances

Slika 9.10h. Jedan mali elektromotor sa ventilatorom za hlađenje, bez priključne
kutije za ugradnju u električne aparate
Figure 9.10h. One small electric motor with cooling fan, without terminal box
for installation in electrical appliances

Slika 9.11. Priključna kutija elektromotora horizontalno montirana na gornjoj strani
kućišta i sa dva kablovksa uvodnika za energetske kablove kojima se motor
priključuje na mrežu i jednim uvodnikom za zaštitne elemente statorskih
namotaja
Figure 9.11. Electric motor terminal box mounted horizontally on the upper
side of the housing and with two cable glands for power cables that connect
the motor to the mains and one cable gland for the protective elements of
the stator windings
Sika 9.12. Izgled jedne priključne kutije trofaznog kratkospojenog elektromotora
američke proizvodnje u toku priključivanja od strane autora Radoja Jankovica iz
mladih dana kada radio kao elektro monter i na održavanju eletro instalacija svih
vrsta.
Sika 9.12. Appearance of a connection box of a three-phase short-circuited
electric motor of American production during the connection by the author
Radoje Jankovic from his young days when he worked as an electrician and
in the maintenance of electrical installations of all kinds.

Slika 9.13. Elektromotor sa horizontalno-koso montiranom priključnom kutijom.
Figure 9.13. Electric motor with horizontally-mounted junction box.

Slika 9.14. Elektromotor sa tri kablovska uvodnika i priključnom kutijom
montiranom pod uglom sa strane. Takođe se ispod kutije vidi stezaljka na stopi
kućišta  sa žutozelenim provodnikom za uzemljenje kojim je motor spojen na
metalnu konstrukciju
Figure 9.14. Electric motor with three cable glands and terminal box mounted
at an angle to the side. Also under the box is a terminal on the housing foot
with a yellow-green ground wire that connects the motor to the metal
structure
>
Slika 9.15. Elektromotor sa horizontalno montiranom priključnom  kutijom na
gornjoj strani motora
Figure 9.15. Electric motor with horizontally mounted terminal box on the top
of the motor

Slika 9.16. Trofazni elektromotor sa vertikalno montiranom priključnom kutijom,
približno na sredini dužine elektromotora
Figure 9.16. Three-phase electric motor with vertically mounted terminal box,
approximately in the middle of the length of the electric motor.

Slika 9.17. Elektromotor potpino zatvorene konstrukcije sa ventilatorima za
hlađenje sa obe strane.
Figure 9.17. Electric motor of completely closed construction with cooling fans
on both sides

Slika 9.18. Vertikalno montirane tri priključne kutije na jednom visokonaponskom
elektromotoru velike snage sa sistemom za hlađenje motora montiranog na
gornjoj strain motora
Figure 9.18. Vertically mounted three junction boxes on one high-voltage
high-voltage electric motor with engine cooling system mounted on the
upper side of the motor

Slika 9.19. Vertikalno montirana priključna kutija na jednom trofaznom
elektromotoru sa reduktorom
Figure 9.19. Vertically mounted terminal box on a one three-phase electric
motor with geabox for reducing the numbers of rotations to lower number

Slika 9.20. Vertikalno montirana priključna kutija jednog visokonaponskog
elektromotora sa hladnjakom  na gornoj strani za hlađenje motora
Figure 9.20. Vertically mounted terminal box of a high-voltage electric motor
with a radiator on the upper side for motor cooling

Slika 9.21. Vertikalno postavljena priključna kutija jednog trofaznog asinhronog
elektromotora za pogon crpne pumpe u toku montiranja
Figure 9.21. Vertically mounted terminal box of a three-phase asynchronous electric motor for pump operation during mounting

Slika 9.22A…
Figure 9.22A…

….I slika 9.22B.
… and figure 9.22B.
Na ove dve ogromne rudarske mašine (ilustrativna slika 9.22A i 9.22B), rotacioni
bageri glodari, na svakoj od njih postoji preko 50-80  trofaznih niskonaponskih i
visokonaponski elektromotora od malih nekoliko kilovata snage do velikih od više
stotina kilovata a takođe i motora jednosmerne struje. Priključne kutije o kojima
govorimo ovde,  kod ovih elektromotora su razlitih konstrukcija.
On these two huge mining machines (illustrative figures 9.22A and 9.22B),
rotary excavators rodents, on each of them there are over 50-80 three-phase
low-voltage and high-voltage electric motors from a few kilowatts to
large hundreds of kilowatts and also DC motors. The junction boxes we are
talking about here, with these electric motors, are of different constructions.

Slika 9.23. Priključna kutija elektromotora u horizontalno-kosom položaju na
motoru u odnosu na vertikalu.
Figure 9.23. Connection box of the electric motor in the horizontal-oblique
position on the motor in relation to the vertical.

Slika 9.24. Priklljučna kutija postavljena pod malim uglom u odnosu na vertikalu,
levo sa tri kablovska uvodnika i priključna kutija desno takođe postavljena pod
uglom sa tri uvodnika za zaštitne elemente ugrađene u statoru elektromotora  
Figure 9.24. Terminal box placed at a small angle to the vertical, left with three
cable glands and terminal box on the right also positioned at an angle with
three glands for protective elements built into the stator of the electric motor
Slika 9.25. Trofazni elektromotor sa dve priključne kutije na motoru u
horizontalnom položaju a pomoćna kutija sa strane u kosom položaju.
Figure 9.25. Three-phase electric motor with two junction boxes on the motor
in horizontal position and the auxiliary box on the side in an oblique
position.

Slika 9.26. Trofazni elektromotor vertikalnog tipa sa priključnom kutijom takođe u
vertikalnom položaju
Figure 9.26. Three-phase electric motor of vertical type with terminal box also
in vertical position
Slika 9.27. Trofazni elektromotor sa velikom priključnom kutijom na gornjoj strani
kućišta motora. Vidimo da je priključna kutija ovog elektromotora dosta velika u
odnosu na gabarite samog motora
Figure 9.27. Three-phase electric motor with a large terminal box on the upper
side of the motor housing. We see that the terminal box of this electric
motor is quite large in relation to the dimensions of the motor itself

Slika 9.28. Trofazni elektromotor potpupno zatvorenog tipa. Kućište je gvozdeno
Izliveno od sivog liva iz jednog dela sa priključnom kutijom.
Figure 9.28. Three-phase electric motor of completely closed type. The housing is made of cast iron in one piece with a junction box.
  1. PRIKLJUČNE KUTIJE ZA VISOKONAPONSKE ELEKTROMOTORE

Priključne kutije za visokonaponske elektromotore su takođe standardizovane kod kojih se određuje međusobni položaj triju stezaljki, položaj prema stiku (dodirna površina između priključne kutije i njenog poklopca) i prema otvoru priključne kutije za uvod kablova, zatim veličinu tvora za uvod kablova u zavisnosti od nazivne struje kao i najmanje razmake ovojnih površina, kosi položaj stezaljki na motoru i položaj i dimenzije prirubnice za prigradnju priključne kutije što je prikazano na slikama 9.27 i 9.28.

Napominjemo da postoji mnogo različitih oblika priključnih kutija za visokonaponske elektromotore sa različitim položajima montiranja istih.

Za mrežne snage kratkog spoja preko 200 MVA treba primeniti najmanje priključne svornjake (bolcnove) sa navojem M16 mm. Redosled stezaljki U1, V1, W1, (U, V, W) odgovara redosledu faza pri desnom smeru obrtanja rotora.

Otvori priključnih kutija, po potrebi sa obe strane električne mašine, moraju za određene veličine mašine biti najmanje 300 mm ili već kako je definisano određenim propisima iznad površine naleganja mašine. Priključa kutija bi trebala biti postavljena aksijalno po mogućnosti na sredini između simetrala rupa u nogama za pričvršćivanje električne mašine. Kada nije drukčije ugovoreno, priključna kutija se nalazi na desnoj strani mašine, gledano s pogonske strane.

Ako je potrebna, priključna kutija zvezdišta postavlja se na suprotnoj strani. Na prethodnim slikama prikazano je nekolik različitih priključnih kutija visokonaponskih elektromotora.  

B.CONNECTION BOXES FOR HIGH VOLTAGE ELECTRIC MOTORS

Terminal boxes for high-voltage electric motors are also standardized, which determine the position of the three terminals, the position according to the contact (contact surface between the terminal box and its cover) and according to the opening of the terminal box for cable entry, then the size of cable entry depending on rated current as well as the smallest distances of the envelope surfaces, the oblique position of the terminals on the motor and the position and dimensions flanges for mounting the terminal box as shown in Figures 9.27 and 9.28.

Please note that there are many different types of junction boxes for high voltage electric motors with different mounting positions.For short-circuit mains over 200 MVA, the smallest M16 mm bolts should be used. The order of terminals U1, V1, W1, (U, V, W) corresponds to the order of phases in the right direction of rotation of the rotor.

The openings of the junction boxes, if necessary on both sides of the electric machine, must be at least 300 mm for certain machine sizes or already as defined by certain regulations above the bearing surface of the machine. Thejunction box should be placed axially, preferably in the middle between the bisectors of the holes in the legs for attaching the electrical machine. Unless otherwise agreed, the terminal box is located on the right side of themachine, viewed from the drive side.

If necessary, the star box is placed on the opposite side. The previous pictures show several different junction boxes of high voltage electric motors.


Slika 9.29. Primer jedne priključne kutije sa dimenzijama za električne mašine sa
nazivnim naponom 6 kV. Treba naglasiti da postoji mnogo različitih oblika
priključnih kutija za visokonaponske elektromotore.
Figure 9.29. Example of a terminal box with dimensions for electrical machines
with a nominal voltage of 6 kV. It should be emphasized that there are many
different forms of junction boxes for high voltage electric motors.

Slika 9.30. Ove dve slike prikazuju položaj montiranja priključne kutije kod
elektromotora sa nazivnim naponom 6 kV. Naravno, postoji čitan niz različitih
konstruktivnih rešenja sa položajima montiranja priključnih kutija
Figure 9.30. These two figures show the mounting position of the terminal box
for electric motors with a nominal voltage of 6 kV. Of course, there are a
number of different design solutions with mounting positions for junction
boxes

See us for a some time again.

About the Author

- Radoje - Rade Jankovic Electrician, Electrical Technician, Electrical Engineer, PhD, Ecologist, Environmentalist, Designer, Educator, Investigator... Today PROFESSIONAL TECHNICAL WRITER AND DOCUMENTATOR Massive practical experience in almost all fields of electrical engineering over 40 years. My International education group in Facebook: EEEW - ELECTRICAL & ELECTRONIC EDUCATION WORLD where published more than 8000 small or bigger articles, lessons, technical advice, projects, technical calculations, test questions with and without answers, illustrated test questions with and without answers; all my original works and few thousands of may original photos from practice, drawings, circuit diagrams, environmental lessons and examples from everyday practice etc., etc.

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