You will need

- tester;
- - a set of wires;
- - current source with adjustable power;
- - frequency Converter.

Instruction

1

Connect the motor to a current source of variable EMF. Increase its value. Along with it will increase the voltage on the motor winding. Keep in mind that if we neglect losses in the supply conductors, which are very small, then the EMF source equal to the voltage on the windings. Calculate the magnification power of the motor. To do this, find how many times the increased tension, and lift this value into a square.

2

Example. The voltage on the windings of the motor was increased from 110 to 220 V. how many times has increased its power? The voltage increased to 220/110=2 times. Therefore, the engine power was more in 22=4 times.

3

Rewind the motor windings. The vast majority of cases, to the winding of the motor is used copper wire. Use wire of the same length, but with a greater section. The resistance of the winding will decrease and current and power of the engine at the same time increase. The voltage on the windings must remain constant.

4

Example. A motor with a winding cross-section 0.5 mm2 wound wire with a cross section of 0.75 mm2. How many times has increased its capacity if the voltage value constant? The cross section of the winding is increased 0,75/0,5=1,5 times. At the same time increased engine power.

5

When switching on three-phase asynchronous motor in single-phase domestic network, increase its useful capacity. To do this, disable one of its windings. Disappear the braking torque generated in all the windings, and the output power of the engine will increase.

6

Increase the capacity of asynchronous AC motor, increasing the frequency of the AC current flowing through the windings. To do this to the engine, attach the frequency Converter. Increasing the frequency of the applied current, increase the power of the motor. The value of the power capture by the tester operating in the mode of the power meter.

# Advice 2: How to determine motor power

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Instruction

1

AC motors are divided into two major classes: synchronous and asynchronous.

The principal difference from the first second is that in induction motors, you can change the speed of the output shaft end, which allows increase the life of equipment and reduce energy costs. One of the most important characteristics of any

The principal difference from the first second is that in induction motors, you can change the speed of the output shaft end, which allows increase the life of equipment and reduce energy costs. One of the most important characteristics of any

**motor**, be it synchronous or asynchronous, is its**power**. The power**of the motor**, normally indicated in its technical passport.2

If the document was lost or not given this important feature, then define

**the capacity**can be according to the stator core. The product of a constant depending on the dimensions of the machine, and its speed, square of the inner diameter of the stator, its length (including ventilation ducts), synchronous speed (determined by using the tachometer) to ten to the minus sixth degree is the required amount of power**to the motor**.3

Another way to determine

**capacity**is similar to a school science lab. Includes motor, measure it voltage and current of each phase with a voltmeter and ammeter, respectively (devices must be connected in series). Then calculate full**capacity**for a very simple formula. Found the voltage multiplied by the sum of currents in phases.4

You can also take the measurements

**of the motor**(length, shaft diameters) and define the directory to which series is your engine. Knowing the series, you will learn and**the power**that is given in this Handbook.# Advice 3: How to find out the motor power

In that case, if after a careful examination of the body of

**the motor**was not able to find the value of its capacity, calculate it yourself. To calculate the power consumption measure the current on the windings of the rotor and using the formula find the consumed electric**power**. You can determine the motor power, knowing its structure and dimensions. To calculate the net power of the motor, find the frequency of rotation of its shaft and the torque on it.You will need

- current source, an ammeter, a ruler, the table is based on a constant engine of the number of poles, the load on the stand.

Instruction

1

Definition of engine power by chocopotle the motor to a source of current and the known voltage. After that, including the circuit of each of the windings ammeter, measure operating current of the motor in amperes. Find the sum of all measured currents. The resulting number multiply by the voltage value, the result is power consumption of the electric motor in watts.

2

The definition of the motor power according to his habitualmente inner diameter of stator core and its length together with the air channels in centimeters. Find out the frequency of the alternating current network to which the connected motor and the synchronous speed of the shaft. To determine the constant of the pole dividing the product of the core diameter on the frequency of the synchronous shaft, multiply by 3.14 and divide successively on the network frequency and the number 120 (3,14•D•n/(120•f)). It will be a pole dividing machine. Find the number of poles and multiply by 60 the frequency of the current in the network and dividing the result by the frequency of rotation of the shaft. Multiply the result by 2. According to these data in the table to determine the dependence of the constant of a motor With the number of poles, find the value of the constant. This constant and multiply by the square of the core diameter, the length, and the synchronous rotational speed, and multiply the result by 10^(-6) (P = C•D2•l•n•10^(-6)). The power value will get kilowatts.

3

Determination of power delivered elektrodvigatelei own speed of rotation of the motor shaft with a tachometer in revolutions per second. Then use a dynamometer, determine the tractive effort of the engine. To get the value of the output power in watts, multiply the speed by the number of 6.28, the value of the force and the radius of the shaft, which measure with a ruler or caliper.

# Advice 4: How to calculate motor power

**The power**

**of the motor**, usually specified in the technical documentation or in the type plate on the case. If so it is impossible to find, calculate it yourself. This can be done by measuring the current in the windings and the voltage source. You can also determine its capacity size. Useful power is calculated by the shaft speed.

You will need

- tester;
- - table of dependence of a constant of the motor the number of poles;
- - dynamometer.

Instruction

1

Turn the motor on by connecting it to a power source with nominal voltage for which it is designed. Connect the tester in series to each winding, setting it to measure current. Find the product of the current in each winding and the voltage. The results fold. This will be the rated power of the electric motor. Voltage is measure in volts, current in amps, then get the engine power in watts.

2

To determine the power

**of the motor**without attaching it to the electric network, follow these steps: 1. A caliper measure the inner diameter of the stator core and the length in millimeters. 2. Determine the frequency of the current in the network. 3. Determine the synchronous speed of the shaft. 4. The number 3,14 multiply the diameter of the core and the synchronous frequency of the shaft. Divide the result by the number 120 and the current frequency of the network. The resulting number of pole division of the scale. 5. Find the number of poles, by multiplying the frequency by 120 and dividing the frequency of rotation of the motor shaft. 6. In the specialized table, at the intersection of the values of the pole division and the number of poles of the permanent way**of the motor**. 7. Multiply by a constant core diameter squared, length, and synchronous speed. To obtain the power in kilowatts multiply the result by 10^(-6).3

To determine the useful power

**of the motor**using a tachometer measure the rpm of shaft in Hertz (revolutions per second). A dynamometer, determine the pulling force developed in it. For this operation it is best to use a special stand. To determine the value of the net power**of the motor**, multiply the number 3,14 on the measured power, frequency of rotation of the shaft and its diameter.# Advice 5: How to increase the frequency of the current

Due to increased migration along the chain of charges increases the frequency

**of the current**. In turn, the increase in the number migrated per unit of time charges amounted to an increase**of current**in the circuit and reduce its resistance, and this can be achieved by using a circuit with a capacitor.You will need

- - capacitor;
- generator;
- key;
- - wires.

Instruction

1

Assemble the circuit with the capacitor, in which a sinusoidal voltage creates a generator of alternating

**current**.2

At zero voltage in the time circuit key in the first quarter of the period the voltage at the generator terminals will increase, and the capacitor will start charging. In the assembled chain will appear current, but, despite the fact that the voltage on the plates of the generator is still quite small, the value of the

**current**in the circuit will be greatest (the value of its charge).3

Note that decreasing the discharge of the capacitor increased

**current**in the circuit is reduced, and the total discharge current is zero. The value of the voltage on the plates of the capacitor will continue to grow, and at the time of full discharge of the capacitor reaches the maximum value (i.e. the value will be completely opposite to the voltage on the plates of the generator). Thus, we can conclude: in the initial moment of time the current with the greatest power will flock to the uncharged capacitor, and the charging will start to decrease.Note

Remember that an increase in the frequency of the current decreases and the resistance of the capacitor alternating current (capacitive resistance of the capacitor). Thus, the resistance capacity is inversely proportional to the capacitance circuit and the frequency of the feeding current.

Useful advice

Capacitor – a unique item. When he discharged, it behaves like a short circuit – the current through it flows without restrictions, and its value tends to infinity. When he charged, at this point, the circuit is open and the circuit starts to continuously increase. It turns out an interesting relationship – there is voltage but no current, and Vice versa. Therefore, to increase the frequency of the current is possible only in case of a weak capacitor, which is in such a condition with a certain interval as many times as necessary. Use this information when creating a circuit.