Instruction

1

Single-phase asynchronous

**motor**is designed for a voltage of 220 V. It is enough to connect to the network. Remember, however, that the simplicity of the motor connection of this type turns into a major disadvantage — low efficiency.2

Two-phase motors, also called a condenser, require two parts: paper capacitor for a voltage of less than 500 (the capacity stated in the Handbook either directly on the engine), and in some cases step-down autotransformer, because most of these motors designed for a voltage of 110 V. On the windings, which is designed for direct connection, apply this voltage directly, while the rest is through connected in series with it a capacitor. Use any other capacitors in addition to paper, is not allowed.

3

Three phase motors to work as the condenser is not designed. Use them in this capacity only at very small load on the shaft, otherwise it will stop, and the windings will burn out from overload. At nominal load feed this engine only from real three-phase network.

4

To connect with universal motor (commutator serial excitement) sequentially connect the field winding and the collector-brush unit. Then, after having loaded the motor shaft the mechanism with which it will be used (this is mandatory), apply to this Daisy-chain supply voltage.

5

Brushed DC motors are usually low voltage. To enable this motor into a 220-volt network, use the appropriate parameters of the power supply, consisting of transformer and rectifier.

Note

Do not touch live parts under voltage. Beware of mechanical injuries. Use the engine, the voltage to which it was designed.

# Advice 2: How to calculate motor

If you decide to make the motor, you will need an accurate calculation of the characteristics of his work. After all, this will depend on whether he will be able to perform their functions or not.

Instruction

1

To get started please read the methodological literature on the subject. The most complete method of manufacture and calculation of motors of different models are reflected in the manual N. In.Vinogradova "How to calculate motor", 1974

2

Identify the main dimensions of the motor, that is, the length of the rotor and its diameter.

3

Then calculate perforated layer, that is, the size of teeth and grooves.

4

Determine the winding data, that is, how many turns present in the coil and what is the diameter of the wire. Calculate the magnetic fluxes and the main induction in the parts of the rotor and stator. If you plan to manufacture the collector machine, you will need to determine the size of reservoir, number and size of brushes.

5

Determine the power loss that will occur inside the motor. In devices of small capacity calculation is performed on the basis of the strength of the bearings, manifold and shaft.

6

If you produce a complete and accurate calculate, you will need to do so - it will need a shared notebook. However, you can do simplified calculations, which include determination of the size of the magnetic core and the receiving winding data. All other measurements and calculations can be avoided, since the solution of physical tasks do not need to strive for completely accurate data. For example, the engine will not be exposed to excessive heat, so no thermal calculations you can do. Thus, the manufacture of the motor is quite possible, provided that you have at least basic knowledge in physics and electrical engineering. Study in detail the issue, conduct the necessary calculations and try to collect his first engine.

# Advice 3: Why 220 Volts

Voltage 220V used in home power, is dangerous to life. Why not begin to organize in the homes of the 12-volt network and produce the corresponding electrical appliances? It turns out that such a decision would be very inefficient.

The power allocated to the load equal to the product of voltage on it and passing through it current. It follows that the same power can be obtained using an infinite number of combinations of currents and voltages - the main thing to work every time was the same. For example, the power output of 100 W can be obtained by 1 V and 100 A or 50 V and 2 A, or 200 V and 0.5 A, and so on. The main thing - to make a load with so much resistance that when the desired voltage is passed through it the required current (according to Ohm's law).

But the power stands out not only on load but also on the lead wires. This is detrimental because this power is lost useless. Now imagine that for the power load capacity of 100 watts uses conductors with a total resistance of 1 Ohm. If the load is supplied with voltage of 10 V, to obtain such capacity through it will have to pass a current of 10 A. that is, the load must have a resistance of 1 Ohm, comparable to the resistance of conductors. So, they will have lost exactly half of the supply voltage, and therefore power. So in this scheme, the power load developed at 100 watts, you will have to raise the voltage from 10 to 20, and in heating the conductors will be of no use to save even 10 V * 10 A = 100 watts.

If 100 watts are obtained when the combined voltage to 200 V and current 0.5 A, the conductor resistance of 1 Ohm will drop the voltage of only 0.5 V, and the capacity allocated to them, will be only 0.5 V * 0.5 A = 0.25 W. Agree, such a loss can be neglected.

It would seem that when 12 volt power is also possible to reduce losses by using thicker conductors have less resistance. But they will be very expensive. Therefore, low-voltage power is used only where the conductors are very short, and so they can afford to make thick. For example, in computers such conductors located between the power supply and the motherboard, in vehicles - between the battery and the electrical system.

What if, on the contrary, to apply in home electrical lot of tension? Because then the conductors can be made very thin. It turns out that this solution is also unsuitable for practical use. High voltage can penetrate the insulation. In this case it would be dangerous to touch not only exposed wires but also isolated. Why do only the high-voltage transmission lines, which saves a huge amount of metal. Before serving in the house this voltage is lowered to 220 V via transformers.

A voltage of 240 V, as a compromise (one side, not piercing the insulation, and on the other, allowing to use for household wiring is relatively thin wires), proposed the use of Nikola Tesla. But in the US, where he lived and worked, this proposal was not heeded. There are still applied voltage 110V - too dangerous, but to a lesser degree. In Western Europe the voltage is 240 V, that is, as much as Tesla suggested. In the USSR there are primarily two voltage: 220V in rural areas and 127 in the cities, it was then decided to transfer to the first of these stresses and the city. It is now widely used in Russia and the CIS. The most low is the Japanese grid. The voltage it is only 100 V.

# Advice 4: How to run three phase motor from 220 volts

The main application of three phase motors is considered to be industrial production. But sometimes you need to use this engine in the farm. You need to make simple calculations and perform simple wiring.

Instruction

1

As a rule, for connection of three phase motor uses three wires and a supply voltage of 380 volts. The network is 220 volts with only two wires, so the engine has started, the third wire also need to apply tension. For this purpose, the condenser, which is called a condenser.

2

The capacitance of the capacitor depends on the power of the engine and is calculated by the formula:

C=66*P, where C is the capacitance of the capacitor, UF, P – electric motor power, kW.

That is, for every 100 watts of power the engine needs to pick up about 7 µf of capacitance. Thus, for the engine power of 500 watt need a capacitor with a capacitance of 35 µf.

The required capacity can be assembled from several smaller capacitors by connecting them in parallel. Then the total capacity is counted by formula:

Sobsch = C1+C2+C3+.....+Cn

It is important to remember that the working voltage of a capacitor should be 1.5 times the motor power. Consequently, when the supply voltage is 220 volts, the capacitor must be 400 volts. Capacitors you can use the following type of KBG, MBGC, OSH.

C=66*P, where C is the capacitance of the capacitor, UF, P – electric motor power, kW.

That is, for every 100 watts of power the engine needs to pick up about 7 µf of capacitance. Thus, for the engine power of 500 watt need a capacitor with a capacitance of 35 µf.

The required capacity can be assembled from several smaller capacitors by connecting them in parallel. Then the total capacity is counted by formula:

Sobsch = C1+C2+C3+.....+Cn

It is important to remember that the working voltage of a capacitor should be 1.5 times the motor power. Consequently, when the supply voltage is 220 volts, the capacitor must be 400 volts. Capacitors you can use the following type of KBG, MBGC, OSH.

3

For motor connection use two connection schemes is the "triangle" and "star".

4

If the three-phase motor has been connected according to the scheme "triangle", then to single-phase network connected on the same circuit with addition of capacitor.

5

Motor connection star performed according to the following scheme.

6

For the operation of the motors power up to 1.5 kW is sufficient capacitance of the operating capacitor. If you connect the engine more power, this engine will be very slow to accelerate. It is therefore necessary to use a starting capacitor. It is connected in parallel with the working capacitor and is used only during acceleration of the engine. Then the capacitor is disconnected. The capacitance of the capacitor to run the motor needs to be 2-3 times more than the capacity of the worker.

7

After starting the engine, determine the direction of rotation. It is usually necessary that the motor rotate clockwise. If the rotation is in the right direction to do nothing. To change direction, you must do the rewiring of the engine. Disconnect any two wires, swap them and reconnect. The direction of rotation will reverse.

8

When performing electrical work observe safety regulations and use the individual means of protection against electric shock.