- 1 How to connect a three-phase motor 220 to the network
- 1.0.1 The principles of operation of three-phase asynchronous motors
- 18.104.22.168 induction motor apparatus
- 22.214.171.124 What is a three-phase current
- 126.96.36.199 How does a three-phase induction motor
- 188.8.131.52 Connection methods of induction motors the windings
- 184.108.40.206 Video: Great movie about three-phase synchronous motors, which have not yet had time to paint
- 1.0.2 How to connect a three-phase motor 220 to the network
- 220.127.116.11 The phase shift using capacitors
- 18.104.22.168 Sequential and parallel connection of capacitors
- 22.214.171.124 The use of electrolytic capacitors as launchers
- 126.96.36.199 Required tools and accessories
- 188.8.131.52 Connection of a three-phase motor in a single-phase network 220
- 1.0.3 conclusion
- 1.0.4 Video: How to connect the motor to the 220
- 1.0.1 The principles of operation of three-phase asynchronous motors
How to connect a three-phase motor 220 to the network
Three-phase asynchronous motors are completely deserved the most widespread in the world, because they are very reliable, require minimal maintenance, easy to manufacture and do not require you connect any complicated and expensive devices, unless you want to adjust the speed. Most of the machines in the world is driven by three-phase asynchronous motors, they also drive the pumps, actuators of various useful and necessary arrangements.
But what about those who are in the personal home ownership is not a three-phase power supply, and in most cases it is. What if I want to put in a home workshop stationary circular saw or lathe elektrofuganok? Want to please readers of our portal, that the way out of this predicament is, and simply implemented. In this article we are going to tell you how to connect the three-phase motor in a network of 220 V.
How to connect a three-phase motor 220 to the network
The principles of operation of three-phase asynchronous motors
Let us consider briefly the principle of operation of an induction motor in its "native" three-phase 380 V. This will help later to adapt the engine to work in other, "non native" conditions - single phase 220 V.
induction motor apparatus
Most produced in the world of three-phase motors - are asynchronous motors with squirrel-cage rotor (ADKZ), which have no electrical contact connection of the stator and rotor. This is their main advantage, because the brushes and collectors - the weakest point of any motor, they are subject to heavy wear, require maintenance and periodic replacement.
Consider ADKZ device. Engine sectional view shown in Fig.
The three-phase asynchronous motor with squirrel-cage rotor sectional
The molded body (7) is assembled the whole mechanism of the motor, comprising two main parts - a fixed stator and a movable rotor. The stator has a core (3) which is assembled from sheets of special electrical steel (alloy of iron and silicon), which has good magnetic properties. The core is assembled from sheets due to the fact that, in the alternating magnetic field in the conductors can occur eddy eddy currents, which in the stator, we absolutely do not need. Further, each core sheet has coated on both sides with special lacquer to generally negate leakage currents. We only need the core of the magnetic properties, not properties of the conductor of electric current.
The stacked core winding slots (2) made of enameled copper wire. To be precise, the windings in a three phase induction motor at least three - one for each phase. Wherein the winding is stacked in the grooves of the core with a certain order - each disposed so that the angular distance is at 120 ° to the other. The ends of windings withdrawn into the terminal box (in the figure it is located in the lower part of the engine).
A rotor placed inside the stator core and rotates freely on the shaft (1). The gap between the stator and the rotor are trying to improve efficiency to make the minimum - from 3 mm up to half a millimeter. The rotor core (5) is also recruited from electrical steel, and it also has slots, but they are not intended for the winding of the wire, and for short-conductors, which are arranged in space in such a way that they resemble squirrel cage (4), for which he received his name.
Proteins can be proud that their honor was named one of the main parts of the engine
Squirrel cage consists of longitudinal conductors which are connected mechanically and electrically to the end rings Typically squirrel cage is manufactured by pouring molten aluminum into the slots of the core, and along another molded monolith and the ring and the fan impeller (6). In ADKZ high power conductors as the cells are used copper rods welded with copper end rings.
What is a three-phase current
In order to understand what forces cause the rotor to rotate ADKZ, it is necessary to consider what the three-phase power supply system, then everything will fall into place. We are all accustomed to the conventional single-phase system, when the outlet there are only two or three terminals, of which one phase (L), a second working zero (N), and the third protective zero (PE). RMS phase voltage in the single-phase system (the voltage between phase and neutral) is equal to 220 V. The voltage (and the connected load and current) in the single-phase networks vary sinusoidally.
Schedule a sinusoidal alternating voltage.
From the above graph amplitude-time characteristics it can be seen that the voltage amplitude value is not 220, and 310 V. The authors consider it their duty to inform the readers did not have any "neponyatok" and doubt that 220 - it's not the peak value and the rms or acting. He still U = Umax / √2 = 310 / 1,414≈220 Q. Why is this done? Only for the convenience of calculation. For reference take a DC voltage to produce some work according to his ability. We can say that a sinusoidal voltage with a peak value at 310 V for a certain period of time will produce the same work, which would make the constant voltage 220 during the same time interval.
We must say at once that almost all generated three-phase electrical energy in the world. Just with a single-phase power is easier to manage in everyday life, the majority of consumers of electricity and enough for one phase of the work, and the single-phase wiring is much cheaper. Therefore, from the three-phase system "pulled out" one phase and the neutral conductor and sent to the consumers - flats or houses. This is clearly seen in the access panels, which illustrates a single phase is carried out in one flat on the other to the second, the third in the third. It is also clearly visible in the pillars on which lines go to private households.
Three-phase power supply, as opposed to a single phase, has not one phase wire, and three: phase A, phase B and phase C. The phases may still be denoted L1, L2, L3. Furthermore phase conductors, of course, there is still common for all phases working zero (N) and the protective zero (PE). Consider the amplitude-time profile of the three-phase voltage.
The amplitude and temporal characteristics of the three-phase current vector diagram
The graphs show that the three-phase voltage - a set of three-phase, with an amplitude of 310 V and RMS phase (phase working zero) voltage to 220 V, and phase shifted relative to each other with an angular distance of 2 * π / 3 or 120 ° . The potential difference between two phases is called the line voltage and is equal to 380, since the vector sum of the two voltages will Ul = 2 *Uf *sin (60 °) = 2 * 220 *√3 / 2 = 220 *√3 = 220 * 1.73 = 380.6 in, Where Ul - the line voltage between two phases, and Uf - phase voltage between phase and neutral.
Three-phase current is easy to generate a transmit to a destination in the future be converted into any desired form of energy. Including into mechanical energy of rotation ADKZ.
How does a three-phase induction motor
If you submit a three-phase alternating voltage on the stator, then through them currents begin to flow. They, in turn, will cause the magnetic fluxes, also varies sinusoidally and also phase-shifted by 2 * π / 3 = 120 °. Given that the stator winding disposed in the space at the same angular distance - 120 °, the rotating magnetic field is formed inside the stator core.
Changing the phase-shifted by 120 degrees currents of the stator windings create a rotating magnetic field,
This constantly varying field crosses the "squirrel cage" rotor and causes it EMF (electromotive force), which will also be proportional to the rate of change of magnetic flux, which in mathematical language means the derivative of the magnetic flux with respect to time. Since the magnetic flux varies sinusoidally, then the EMF will vary according to the cosine law, because (sinx) '=cosx. From school mathematics it is known that the cosine "ahead" sine on π / 2 = 90 °, i.e., reaches a maximum when the cosine, sinus through it reaches π / 2 &# 8212; a quarter of the period.
Under the influence of EMF in the rotor, or rather, any high currents in squirrel cage, given that the conductors are short-circuited and have low electrical resistance. These currents constitute its magnetic field, which extends around the rotor core and begins to interact with the stator field. Opposite poles, as we know, are attracted and repelled by the same name from each other. Emerging forces create a moment causing the rotor to rotate.
The magnetic field of the stator is rotated with a certain frequency, which depends on the mains and the number of pairs of poles of the windings. Calculated frequency using the following formula:
n1 =f1 * 60 /p, Where
- f1 - frequency alternating current.
- p - number of pole pairs of the stator windings.
With frequency AC is clear - it is in our networks supply is 50 Hz. The number of pole pairs reflects how many pairs of poles available on the coil or coils belonging to one phase. If each phase is connected to one winding spaced at 120 ° from the other, the number of pole pairs is equal to one. If one connected to one phase of the two coils, then the number of pole pairs is equal to two and so on. Accordingly, it is changing the angular distance between the windings. For example, when the number of pole pairs of two, located in the stator phase winding A, which occupies the sector is not 120 °, and 60 °. Then, it is followed by the phase winding B, which occupies the same sector, and then phase C. Next alternation is repeated. With an increase of pole pairs of the windings sector are reduced accordingly. These measures allow to reduce the frequency of rotation of the magnetic field of the stator and rotor respectively.
Here is an example. Suppose the three-phase motor has one pair of poles and connected to three-phase mains frequency of 50 Hz. Then the magnetic field of the stator will rotate at a frequency n1 = 50 * 60/1 = 3000 rev / min. If you increase the number of pole pairs - the same factor decreased speed. In order to raise the engine speed, it is necessary to increase the frequency of the alternating current supplying the coil. To change the direction of rotation, it is necessary to change two phases to the windings
It should be noted that the rotor speed is always lags the rotation frequency of the magnetic field of the stator, so called asynchronous motor. Why is this happening? Imagine that the rotor rotates at the same speed as the magnetic field of the stator. Then the squirrel cage is not "penetrate" the alternating magnetic field, and it will be a constant for the rotor. Accordingly, no induced EMF will cease to flow and current will not flow and the interaction of the magnetic moment disappears, resulting in movement of the rotor. That is why the rotor is "an ongoing effort" to catch up with the stator, but never catch up, since the energy disappears, forcing the rotating motor shaft.
A difference of magnetic field rotational frequencies of the stator and the rotor shaft is called the slip frequency, and is calculated by the formula:
Δn =n1-n2, Where
- n1 - the rotation frequency of the magnetic field of the stator.
- n2 - rotor speed.
Slip ratio called slip frequency to the frequency of rotation of the stator magnetic field, it is calculated by the formula: S = Δn /n1 = (n1&# 8212;n2) / n1.
Connection methods of induction motors the windings
Most ADKZ has three windings, each corresponding to its phase and has a beginning and an end. System notation windings can be different. In modern motors accepted notation windings U, V and W, and their findings indicate numeral 1 start winding and numeral 2 - its end, i.e. the winding U has two outputs U1 and U2, the winding V-V1 and V2, and the winding W - W1 and W2.
However, it is still in operation are asynchronous motors, made in Soviet times and having the old labeling system. They start windings are designated C1, C2, C3, on the ends of the C4, C5, C6. Hence, the first coil has terminals C4 and C1, second C2, and C5, and third C3 and C6. Compliance with the old and new systems of symbols shown in the figure.
Old and new designations of the motor windings
Consider how the windings may be connected in ADKZ.
With this connection, all the ends of the windings are combined to one point and are connected to their beginnings phase. On the concept of a method of connecting really looks like a star, for which he was named.
Connecting the windings of the induction motor star
When star connection to each winding separately applied phase voltage is 220 V, and the two windings connected in series line voltage of 380 V. The main advantage of this method of connection - a small current start, since the line voltage is applied to the two windings, and not to one. This allows the engine to "soft" start, but its capacity will be limited as the flowing currents in the windings will be less than with other connection methods.
When connected windings are combined into a triangle, when the beginning of the winding is connected to one end of the track - and so the circle. If the line voltage three-phase 380 V, through the winding currents will flow much larger quantities than in star connection. Therefore, the electric power will be higher.
Connecting the induction motor winding triangle
The delta connection at startup ADKZ consumes large inrush currents that can be 7-8 times higher than nominal and can cause network congestion, so in practice, the engineers have found a compromise - starting the engine and its unwinding to nominal speed is done on the wye, then occurs automatically switch to a triangle.
How to determine under what scheme the motor windings are connected?
Before connecting the three-phase motor to a single phase 220 V, it is necessary to find out at what circuit connected winding and at which an operating voltage can work ADKZ. For this it is necessary to examine the plate with the specifications - "label", which should be on each engine.
On a plate &# 8212; &# 171; nameplate&# 187 ;, you can learn a lot of useful information
On the label has all the necessary information to help you connect the drive to a single-phase network. In the illustrated label it is seen that the motor has a power of 0.25 kW and the number of revolutions 1370 rev / min, which indicates the presence of two pairs of windings of the poles. Icon Δ / Y means that winding can be connected as a triangle, and star, and the next index 220/380 indicates that the delta connection mains voltage must be 220 V, and in star connection - 380 V. If this The motor is connected to the network 380 in a triangle, its winding will burn.
For the connection of the engine to the network 220 is better not to take
The following rating plate can be seen that such an engine can only connect the star and only network of 380 V. Most likely in the terminal box in such ADKZ is only three pins. Experienced electricians will be able to connect and this engine to 220 V, but it will have to open the back cover to get to the main winding, and then find the beginning and end of each winding and make the necessary switching. The task is much more complicated, so the authors do not recommend connecting such motors to the network 220, as the majority of modern ADKZ can be connected in different ways.
Each engine has a terminal box located on top more often. This box has inputs for feeder cables, and on top of it is covered with a lid, which must be removed with a screwdriver.
As they say electricians and pathologist: &# 171; The autopsy shows&# 187;
Under the lid you can see the six terminals, each of which corresponds to, or top, or the end of the winding. In addition, the terminals are connected to the webs, and their location can be determined by a circuit connected winding.
Opening of the terminal box showed that &# 171; patient&# 187; clear &# 171; star fever&# 187;
In the photo to "open" box shows that the wires leading to the windings signed and bridges are connected at one point the ends of all windings - V2, U2, W2. This indicates that there is a star connection. At first glance it may seem that the ends of the windings are arranged in logical order V2, U2, W2, and the beginning of the "reversed» - W1, V1, U1. However, this is done with a purpose. For this, consider the terminal box ADKZ with connected windings of a delta.
This jumper tells that the winding connected triangle. Instead of one jumper applied pink pigtail
The figure shows that the position of the jumper is changed - joined the beginnings and ends of the windings, the terminals are arranged so that the same jumper used for rewiring. Then it becomes clear why the "mixed up" terminals - so it's easier to throw the jumper. The photograph shows that the terminals U1 and W2 are connected to pigtail, but the basic configuration of the new engines are always present just three jumpers.
If the "opening" of the terminal box found such a picture, as in the photo, it means that the engine is designed for the star and three-phase 380 V.
Such an engine is best to return to his &# 171; native element&# 187; &# 8212; a three-phase AC circuit
Video: Great movie about three-phase synchronous motors, which have not yet had time to paint
How to connect a three-phase motor 220 to the network
Connect the three-phase motor in single phase 220 V can be, but we must be prepared to sacrifice a significant reduction of its capacity - in the best case, it will be 70% of the rating, but for most purposes it is quite acceptable.
The main problem of the connection is to create a rotating magnetic field, which induces voltage in a short-circuited rotor. The three-phase networks to implement it easy. When generating a three-phase electric power in the stator windings is induced emf due to the fact that the core rotates within the magnetized rotor which is driven by the energy of falling water on HPS or steam turbine for hydro and nuclear. It creates a rotating magnetic field. In engines there is an inverse transform - a varying magnetic field causes the rotor to rotate.
The single-phase networks to obtain a rotating magnetic field is difficult - it is necessary to resort to some "tricks". For this purpose it is necessary to shift the phase windings with respect to each other. Ideally, you need to make sure that the phases are shifted relative to each other by 120 °, but in practice it is difficult to implement, since these devices have complex schemes, are quite expensive and their manufacture and setup require specific qualifications. Therefore, in most cases, use simple scheme, with several sacrificing power.
The phase shift using capacitors
Electric capacitor is known for its unique property not to pass DC, but AC skip. The dependence of the currents flowing through the capacitor, the applied voltage is shown on the graph.
Calculated capacitance is better not to increase, since it may lead to overheating of the motor windings. After the engine is started under designed load, it is possible to measure and adjust operating current capacity by calculating it by its dependence on the voltage and current. Most likely, it will be lower. In the motor power less than 500 W starting capacitor may not be necessary, it depends on whether the mechanical load on the rotor shaft. For example, startup of the circular saw, elektrofuganka, emery, - there is no load, a submersible pump - once under load.
When choosing a capacitor, please note that at the time of the launch they may affect a higher voltage than the nominal. Therefore, if the engine will run on the network 220, the capacitor must be rated voltage of not less than 1.5 * 220 = 360 V, and preferably 400-450 V. It is also necessary to take into account the fact that the run capacitor is involved at all times operation of the engine and starter - only during startup. What is the difference and similarities start and run capacitors shown in the following table.
|application||The electrical circuits of asynchronous motors||The electrical circuits of asynchronous motors|
|How to connect||In series with one of the three-phase motor winding or auxiliary winding with a single-phase motor||Parallel to the run capacitor|
|Used as||Element shifts the phase windings in a three-phase motor connected to the single-phase network||Element shifts the phase of a three-phase motor winding|
|appointment||Preparation of the rotating magnetic field necessary to rotate the motor rotor||Preparation of the rotating magnetic field producing increased torque needed to start the motor rotor|
|At what time is connected||At all times of the motor||At the time of the start and set the nominal speed|
Run capacitor is usually in the tens or even hundreds of microfarads. Naturally, the more capacity and higher operating voltage, the more volume will be a capacitor. Consider the following table which capacitors can be used as working and launchers.
|Manufacturing technology||Application of metallized film capacitor paper, which is an insulator||Application of thin metallized films on polypropylene tape||Aluminum foil and an electrolyte. The dielectric used aluminum dioxide|
|Operating voltage,||160, 200, 300, 400, 600, 1000||450, 630 V||In 220-450|
|Range of capacities, uF||0.1-20 mF||1-150 uF||50-1500 uF|
|The material and shape of the housing||Metal Rectangular sealed housing||Plastic cylindrical body in a cylindrical metal CBB65 explosion proof housing||Cylindrical metal flameproof enclosure coated with a film of heat-resistant polyvinyl chloride|
|where to apply||As working capacitor induction motors||As working and starting capacitor induction motors||As a starting capacitor.|
|dignity||a small price||Small, light scatter characteristics, durability||High capacity at small dimensions|
|disadvantages||Large size, high loss, the rapid aging at elevated temperatures||The price is higher than the metallized capacitor||Not recommended for use as working capacitors|
Sequential and parallel connection of capacitors
There is such a need when the hand is not the capacity to the desired nominal value. Most often it is not enough and, "as luck would" have a scattering of other capacitor capacitance. Out of this situation is very simple - if you connect capacitors in parallel, the resulting capacity will be equal to the sum of all of the capacitors. It should be noted that when such a compound is desirable to use all capacitors with a single operating voltage, since the voltage to their electrodes will be identical. For example, it is necessary to collect 50 uF capacitor bank with a voltage of 400 V. For this purpose, you can pick up 5 capacitors 10 uF type MGBO and they should all have the same voltage. If at least one of the capacitors will have a lower voltage, for example 160 V, it is a short time fail.
Sequential and parallel connection of capacitors
Parallel connection make most often. Before, when they were not available metallopolipropilenovye metallized capacitors used, which are connected in parallel and placed in special boxes. On powerful machines such batteries were quite impressive size. Modern capacitors eliminate the need for bulky boxes and can be placed directly on the motor housing.
When connecting the resulting capacitance will not be the sum of, and is calculated by the formula: C =C1 *C2 / (C1 +C2), Where C1, C2 - capacitors connected in series. It is obvious that the resulting capacity will always be smaller than the smallest of all connected in series, because if we multiply both sides of expression 1 / C = 1 / C1 + 1 / C2 + ... + 1 / Ci on C1, we get the C1 /C = 1 +C1 /C2 + ...C1 /Ci, which clearly demonstrates that the ratio of any of the containers to the general will always be greater than one. In the language of mathematics, this means that any of the resulting capacity is more.
At first glance it may seem that the series connection of capacitors is nothing inherently does not, because every microfarads capacitance is worth the money and in the best case, if you connect the two tanks at 40 uF, the resultant will be only a 20 uF. But, as can be seen from the above scheme, the applied voltage is distributed to the capacitors, so if, for example, to connect each of them with an operating voltage of 250 V, then they can be safely put 500 V. The higher the nominal operating voltage of the capacitor, the more expensive it is worth . Therefore, the series connection of capacitors sometimes may also be of practical use.
For convenience, we offer readers of our portal to use a calculator, which calculates the capacity of the two series-connected capacitors.
Calculator: Calculate the resultant capacitance of two series-connected capacitors
The use of electrolytic capacitors as launchers
electrolytic capacitors are widely used in electrical and electronic engineering, which experts call "electrolytes". Their main feature is that as one of the electrodes used electrolyte (acid or alkali), which is impregnated with special paper. The other electrode is an aluminum foil on which a thin layer of Al2O3 is aluminum dioxide. Due to this capacitance electrolytic capacitors is much higher at similar sizes than others.
The flip side of the electrolytic capacitors is to ensure that the conditions of their polarity connections in DC or pulsating current circuits. When the appearance of incorrect wiring or the electrode of the electrolytic capacitor AC voltage begins the accelerated degradation, increased leakage currents, which leads to strong heating. As a result, the pressure inside the capacitor increases, and this may cause an explosion. No wonder there are special notches at the top of the electrolyte body - the so-called valve which is under strong pressure rises just broken, but it will be a controlled explosion.
Since those electrolytic capacitors, which do not comply with the polarity and this can happen
Described earlier in Table actuating CD60 capacitors are electrolytic, but nonpolar which can operate in alternating current circuits. This is achieved in that they use two electrodes of aluminum foil covered with an oxide film, and the paper with the electrolyte is in the middle between them. Naturally, the size (and price) of these capacitors is 1.5-2 times higher than that of conventional electrolytes, but they can be included in the AC circuit.
CD60 start capacitor
The non-polar electrolytic capacitor can be obtained from the two polar, but they must be successively oppositely and interconnect the positive electrodes and negative connect to the network. Then, the resulting capacity will be calculated by the calculator. For example, to obtain a non-polar electrolyte capacity 100 uF and 500 V, it is necessary to connect two oppositely 200 uF capacitor and a voltage of 250 V. That is just a serial connection of capacitors can help.
In practice, often used to connect electrolytic capacitors across the diodes. Schematic diagram of the connection shown in Fig.
Diodes do not allow the capacitors to consume &# 171; forbidden fruit&# 187;
It is known that the diode passes the electrical current only in one direction - from the anode to the cathode. It turns out that the positive half cycle will be restricted solely to the positive side of the capacitor, and the only negative to negative. This will ensure that the work of the capacitor in the normal mode. To discharge the start capacitor is connected parallel to the resistors capacity not less than 2 watts. After start-up and acceleration of the engine starting capacitors are switched off and quickly discharged through the resistors. In this scheme, there is a significant drawback - if the "breaks" the diode, the capacitor begins to operate as a boiler electrolyte. Therefore it is recommended to remove the capacitors to a safe place or put in a box or container.
The authors recommend the use of electrolytic capacitors - both non-polar and polar only in the start-up circuit and acceleration of asynchronous motors. As working it is better not to apply.
Video: Non-polar electrolytic capacitors
Choice concept connection diagram
Some starting and operating capacitors Three-phase connection to the network 220 will not be enough. At first it is necessary to determine under what scheme will connect the engine, and which switching devices are needed for the proper starting and stopping.
Connectivity options of three-phase motors in the network 220, there are many, but in the Article is requested to consider only the two most frequently used and reliable. Schematic diagrams shown in Fig.
Such circuits are actually working
Concept, shown at right, shows the connection ADKZ wye. As previously mentioned, this type of connection suitable for use in single-phase networks 220 only for those engines which are intended for the operating voltage 127/220 V at Δ / Y schemes. The left diagram shows the connection of the induction motor on a delta. In this scheme, applied to C1 and C2 starting electrolytic capacitors connected together with the diodes VD1 and VD2. Explain the purpose of all circuit elements.
- And one and another circuit connected to the network 220 V through connectors XP1 and XP
- For protection from severe overcurrents or short-circuit currents in the circuits applied fuses FU1 and FU They may be replaced by a double-pole circuit breaker with a nominal value of 10 or 16 amperes, depending on the power ADKZ. Automatic is better to take a trip characteristic C or even D. powerful machines
- SA1 - a switch which is used to reverse the motor. Changing its position, you can change the direction of rotation. In some mechanisms, such as lifting, this may very well be useful. In engines power up to 1 kW can be applied toggle type switch 1-2 or the TV key for the current to 5 A.
- SB1, SB1.2, SB1.3 - it contacts the starter push button PNVS-10U2. This device has three pairs of contacts: SB1.1 and SB1.3 - contacts that when you press the "Start" button fixed in the closed position (they are in the starter housing on the left and right), and the contact SB1.2, located in the center only closes when you press the "Start" button. This is very useful when you start the engine and acceleration, keeping the button 1-3 seconds, the engine starts and is gaining momentum with the help of the start capacitor, and then the button is released, and the engine continues to run without them. For engines up to 0.6 kW is used PNVS actuators 10, and for more powerful PNVS-12.
- KM1 and KM in the diagram on the left - this is the current relay and its contacts respectively. It can also be used in the schemes ADKZ connection. When current increases to a value greater than nominal, triggers the relay KM and closes KM1.1 contacts that connect C1 and C2 starting capacitors. When the current to decrease the nominal value KM relay is turned off and opens the contacts KM1.1. operating current increase occurs most often when the mechanical load increases sharply at the rotor shaft ADKZ. As the current relay can be used modular RT-40U.
- In the left diagram the working capacitor C3, and C1 and C2 - launchers. On the right scheme C1 - start-up, and C2 - worker. Resistors R1 2W needed to discharge the start capacitor.
The proposed scheme is successfully working for more than a decade and proved its viability, and therefore recommended to readers of our portal to use.
Required tools and accessories
To connect the motor need not such a large set of electrical and installation tool.
|Set of insulated screwdrivers in various sizes and types of slots||For electrical and installation work.|
|Pliers of different sizes||For electrical work.|
|nippers||For cutting wires.|
|Stripper||To remove the insulation from the wires and cutting the wires or crimping terminals (stripper depends on the model).|
|Screwdriver indicator||To monitor the presence of a phase circuit.|
|multimeter||To measure the voltage, current, check the capacitors and resistors, integrity monitoring of the motor windings.|
|current Clamp||To measure the current in the working ADKZ. Assists in the selection of the worker and the starting capacitor. The use is optional, but desirable.|
|Set keys dielectric||For mounting the jumper wires and the motor terminal box.|
|Electric drill with a set of drill bits for wood and metal||For installation work|
|hammer metalwork||For installation work|
|punch||For punching holes for drilling.|
|Hand Riveter||For fastening of the workers and the starting capacitor to the housing ADKZ. Use optionally, as can be fastened on the bolts, but rivets are preferred because of the possibility samoraskruchivaniya screws when the engine vibration.|
|Soldering 60W||Soldering terminals on the capacitor.|
|Crimper manual||And crimping terminals.|
First of all, before the installation work is necessary to think about where the asynchronous motor is mounted. Depending on the tasks assigned base may be a metal, textolite, wood and others. Also on this basis will have to mount a push starter, operating and start-up capacity, if necessary, current relays and other devices switching control and protection.
Electrolytic capacitors must be removed in a separate box that, with the possible explosion of electrolyte spray does not hit the people. If the equipment is mounted on a table or workbench, you can "hide" capacitors, securing them to the bottom surface of the countertop.
One izsposobov hide capacitors &# 171; away from sin&# 187;
For the installation of an induction motor and connect it to the network 220 will need the following components:
|Plastic box for 4 persons exterior mounting||To accommodate the circuit breaker and the current ADKZ relay.|
|Metal punched tape mounting||For attaching equipment to the base|
|Screws for wood and metal||For fixing equipment|
|Rivets exhausting 3 * 3 * 6 or 8||For fixing the working capacitors to the motor housing|
|Circuit breaker C10 or C16||When power ADKZ to 2 kW is used for automatic 10A (C10). At a power of more than 2 kW - 16 A (C16).|
|Modular current relay RT-40U||To control the current in the phase-shifting motor winding. PT 40U has three current measuring range (A 0.1-1 0.5-5 A 3-30 A), adjustment threshold (10-100%), adjustable dwell time (with 0.2-20 ) and capable of switching power to a load 16 A, 250 V. Suitable optional.|
|The push-button switch (push-post) of the pressing action PNVS-10 or 12-PNVS||To enable the induction motor to the network and its failure, and also to ensure starting. For engines to 6 kW rated power applied PNVS-10, and for ADKZ with P = 0,6-2,2 kW - PNVS-12.|
|Switch tumbler-type TV or TV 1-1 1-2||To ensure the motor reverse. The rated current of the switch must correspond to power ADKZ.|
|The wire mounting PV-3 (PUgV) cross-sectional area of 1.5 or 2.5kb. mm||To connect the equipment. enough DI 1.5 to 3 mm, while for greater at a power of 2.2 kW to ADKZ - 2.5kb. mm.|
|Arrowheads isolated NSHVI pin sleeve for wires of 1.5 and 2.5kb. mm.||For terminating wire crimping mounting PV-3 when connected to the terminals of circuit breakers or current relays.|
|Pivoted ring lugs isolated VNKI||For crimping termination assembly or power cord when connected to the equipment terminals with screws or bolts. Depending on the diameter of the screws or pins selected VNKI 2.5-4, 2.5-5 VNKI, VNKI 2.5-6.|
|Pivoted flat connectors such as "mama" with PVC cuff UIR M||For termination of crimping the wire and cable by connecting job or start capacitor with the appropriate connectors such as "Dad". Tip UIR-M-2,5 Connections for provoda1,5 and 2.5kb. mm.|
|shrink tube||For the isolation capacitors terminals after connecting|
Connection of a three-phase motor in a single-phase network 220
After preparing all the necessary components you need to make sure that the work will be carried out only when de-energized. It should only be possible to connect the lighting and power tools. In the workplace, it is necessary to prepare all the instruments and prepare a box or bucket, which will be dumped garbage.
Milestones for connecting ADKZ represented in the form of a table:
|First of all it is necessary to check the integrity of the motor windings. For this terminal cover is removed, all jumpers are removed, the meter is placed on the measurement of resistance in ohms. Should prozvanivatsya only the beginning and ends of each winding separately. No electrical connections between different windings and between the windings and the motor housing should not be.|
|Multimeter checks the integrity of start-up and operating capacitor. Before testing is necessary to discharge the capacitor by shorting its conclusions. Multimeter for measuring capacitors is placed on the measurement megohms, which should not be less than 2 Mohm after some time until the capacitor is charged. If the device has a capacitance measurement function, the task is simplified.|
|Checks the integrity of diodes and resistors, if they are used in the schemes of the starting capacitor. The diodes must pass direct current only in one direction and in both resistors. Putting the desired limit, it is possible to measure the resistance of resistors.|
|The three-phase asynchronous motor is attached to the base. It will be appreciated that such motors have considerable weight and can vibrate during operation., So the substrate must be robust, massive and stable. The mount can be bolted or nuts with washers on the studs through the anti-vibration pads or rack.|
|Fixed in the intended field equipment switching and protection - box for circuit breaker and current relays, push-button starter PNVS PNVS-10 or-12, switch the motor reverse.|
|For fixing toggle reverse TV 1-2 is sometimes advisable to use the cover of the motor terminal box. To do this, you must first try switch in the box, so that he does not interfere with the connection terminals. Thereafter, a drill hole is drilled with a diameter of 12.1 mm and a tumbler secured to the cover nut.|
|Run capacitors can be mounted separately from the electric motor in boxes, boxes, boxes - all depends on the required capacity. But modern metallopropilenovye capacitors can be attached directly to the ribs ADKZ body with a metal mounting tape. To do this, wrap the capacitor tape and cut the right size, leaving the ears for mounting.|
|Then drilled (if necessary) the hole in the yoke of the metal strip. The main body of the induction motor can be mounting holes, but if they do not, they can be drilled, pre-performing PUNCHING.|
|Fastening of the metal strip of the capacitor to the motor housing is preferably made by rivets, given vibration during operation.|
|A good solution is to mount the working and starting capacitors in a safe location under a table, workbench. In this case, later still, it is desirable to cover the capacitors guard.|
|After fixing all the details begins switching, guided by the concept. Jumpers in the terminal box placed in the position of the star - for engines operating voltage 127/220 V.|
|For engines operating voltage of 380/220 V and circuitry Y / Δ connection jumper circuit for permuted triangle.|
|Workers and starting capacitors can have conclusions in the form of wires, terminals solder terminals, and flat "daddy" at the connectors. Metallized capacitors always have a solder connection, and non-polar electrolytic metallopolipropilenovye - in the form of flat wires or terminals. Most preferably choose capacitors with flat terminals "Dad" - it greatly facilitates the assembly and disassembly when replacing.|
|Measure out and cut off the desired lengths of cable in the light of their tracks together or a single gasket. The ends are cleaned from insulation stripper for a length of 10-11 mm.|
|To connect the wires to the terminal block of the engine and okotsovyvayutsya crimped ferrules VNKI appropriate size wire and a terminal by using Crimper.|
|All wires to the terminals ADKZ to terminate, and then put through the cable entry and snapped up the terminals. On the terminal stud snapped washers and nuts but do not tighten. None of the wires should not go into tension, and it shall be possible to re-okontsovki. If the cable entry gland is equipped with a clamp, it can clamp after pulling wires.|
|To connect the terminals of capacitors, wire ends to terminate the terminals UIR-M using Crimper.|
|After connecting the terminals UIR-M to a capacitor contact is isolated by a suitable diameter heat-shrinkable tube that is fitted on the wire before connecting. You can also use separate terminals.|
|By reversing tumbler TV 1-2 wires are soldered and insulated heat-shrinkable tubing. Similarly, the wires are soldered and metallized capacitors if they are used.|
|To connect PNVS PNVS 10 or 12 can be used either NSHVI lugs (NSHVI (2)) or NVI, it is very convenient to connect a screw connection without disassembly. The use of such terminals in the motor terminal box unacceptable.|
|To connect the modular automatic circuit breakers or current switch is most advisable to use NSHVI tips (NSHVI (2)), which also crimped Crimper.|
|By grounding screw on the motor is required to connect wire terminated with a tip protective VNKI zero (PE) of yellow-green color. This bolt can be located in the terminal box and the outside of the housing. It is marked with a special sign.|
|After checking all the connections and checking with the schematic circuit diagram of induction motor terminals tightened using dielectric key. Also screw clamps are tightened breaker, current relay and the starter PNVS PNVS-10 or-12. The input of the circuit breaker is connected to the conductive plug.|
|The input circuit is energized. With the help of the "Start" button on PNVS is the first trial to start the engine. When all the calculations are correct and the installation is done properly, the engine should start immediately.|
If the engine has started confidently, it - it does not mean that it will continue to work with confidence and, therefore, it should first check at idle, and then under load.
- Even if the idling engine starts to get hot, then you should try to reduce the working capacity of the condenser.
- If the engine by pressing the "Start" button hums but does not start, it is necessary to try to help him do it, krutanuv shaft. If this measure has helped to start the rotor to rotate, you can try to increase slightly the capacity of the starting capacitor.
- If a proposed standard load motor is stopped, the increase of the working capacity of the condenser or applied current relay, which connects the "assistance" starting capacitors. However, it should be remembered that the engine will not be able to give out more power than the passport.
The most correct way of selection of the starting capacitor is working under load current measurement and calculation of its dependence on the voltage and current. Earlier this formula was shown in the table. After the engine is fully configured, again tighten all terminals and close all the cover connection. Wires, if they are a group, can be laid together in a corrugated pipe or place them in a heat-shrinkable tube.
Summarizing the article, the authors once again remind readers that the three-phase motor connection to the network 220 is feasible, and on their own. And, although you have to sacrifice power loss, but the possibilities are endless using various useful mechanisms. Three-phase asynchronous motors offer exceptional reliability, still working "veterans", released in the 50-ies of XX century.
The authors recommend that the readers of the portal before the first start-up did not make the final cut of all components and assemble circuit on the stand. If the tests are successful, then we can already mount all as planned. And do not neglect those councils which were given in this article, because it takes into account years of experience and applied scientific approach.
Successful you run the motor and more useful mechanisms!