The principle of single-phase motor reversing is as follows: single-phase motor has a main winding (working winding or running winding) and a secondary winding (starting winding). There is a starting capacity between the secondary winding and the main winding. For some small load single-phase motor, if the two winding are exactly the same, they can be exchanged with each other; but most single-phase motor with a larger load (such as agricultural motor), the secondary winding coil is thin, the number of turns is large, and the resistance is large. In this case, as long as the head and tail connection of one of the two winding can be reversed, the exchange of power supply L/N is invalid. For the operation of the positive and negative transfer wire of the 4 Kilowatt single-phase motor: First of all, the main and auxiliary winding of the motor must be judged by measuring the resistance value. Usually, the wire diameter of the main winding is larger, the resistance value is smaller, and the number of turns is smaller. If it is a three-terminal connection, 1/3 is the common terminal of the two winding, connected to the L of the AC power supply, and the 2/4 terminal is connected with the starting capacity. If the N terminal of the AC power supply is connected to the terminal 2, then the N terminal is connected to the terminal 4. If it is an agricultural single-phase motor with four terminal (1/2 as the main winding and 3/4 as the auxiliary winding), it should rotate in the opposite direction in the case of forward rotation. The correct way is to exchange the end and tail connection of a winding. In terms of the choice of the capacity, generally, each 100-Watt motor used a capacity of about 2 - 3 microfarads, and the capacity of the 4-Watt motor could be selected accordingly. However, it should be noted that in actual operation, if you are not familiar with the principle and connection of the motor, it is recommended to operate it by a professional technician to avoid damage to the motor or safety accidents. Read more exciting novels for free
For the single-phase motor single-capacity reversing switch connection, it must first be clear that the single-phase motor has a main winding and a secondary winding, and there is a starting capacity between the secondary winding and the main winding. Generally speaking, the resistance value between the three wires of the single-phase motor was measured with a Multimeter. The two wires with the largest resistance were connected in parallel with the other wire (the common end) connected to the power supply. Then, the resistance between the common terminal and the wire connected to both ends of the voltage was measured with the electric block of the Multimeter. The end with a slightly larger resistance was connected to the other end of the power supply, so that the positive rotation could be achieved. To reverse the connection, the power cable connected to one end of the voltage could be changed to the other end. In terms of the reversing switch connection, the reversing switch had different terminal posts. Taking the common connection method as an example, some of the terminal posts of the reversing switch were connected to the power supply, and some of the terminal posts were connected to the motor winding. The terminal in the middle could be connected to the power supply, and the terminal connected to the main winding and the secondary winding of the motor could change the connection mode through the internal structure of the reversing switch during forward and reverse rotation, thus changing the direction of the current to achieve forward and reverse rotation. For example, during forward rotation, the circuit was connected according to a phase sequence, so that the current flowed through each winding of the motor in turn to achieve forward rotation; when it was reversed, the connection inside the reverse switch changed, changing the current phase sequence in the winding, and then realizing reverse rotation. However, there may be differences in the connection of different models of reversing switch, and the actual operation should be carefully judged. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Single-phase 6-wire single-capacity motor, in which 6 wires contain 3 coil, can connect one end of the 3 coil together, the remaining 3 wires, one is connected to the live wire, one is connected to the capacity, and one is connected to the neutral wire. Of the six leads, two were for the main coil, two were for the auxiliary coil, and two were for the centrifugal switch. The three parts, namely, the transformer, the centrifugal switch, and the starting coil, had to be connected in series to form a circuit, which was connected in parallel with the main coil to supply power. If the direction was wrong, the two ends of the main coil could be reversed. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Take the yl100l- 4 single-phase high-horsepower double-value capacity motor used in the concrete cement mortar mixing machine as an example. Its technical parameters are: rated power 4KW, rated voltage 220V, rated current 18A, rotating speed 1440r/min, frequency 50HZ, made of high-quality copper wire. There was also a motor of the same type, with a rated power of 4,000,000, a rated voltage of 200,000, a rated current of 18,000, a rated speed of 1,440,000,000, a rated torgue of 10,000,000, and a frequency of 50HZ. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
For the inspection of the single-phase motor ground (insulation to ground), you can disassemble all the connection terminal of the generator's generator's stators and rotators, and then use a universal meter to measure the insulation of the winding to ground. If the insulation to the ground could reach more than 0.5 megohm, it was normal. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
There were different types of single-phase motor, and the method of connecting the voltage to the voltage was also different: 1. ** General Judgment Method **: - The single-phase motor had a main coil and a secondary coil. The resistance of the main coil was smaller than that of the secondary coil. Usually, the connection method can be determined by measuring the resistance between the motor leads. The two wires with the highest resistance were connected to the power source. 2. ** Connection under different starting modes ** - ** Split-phase start type **: suitable for electric fans, air-conditioner fan motor, washing machine and other motor. The auxiliary starting winding is used to assist the starting. The starting moment is not large, and the running speed is roughly maintained at a fixed value. - ** Starting method with centrifugal switch (two conditions)**: - In the first case, when the motor is still, the centrifugal switch is connected. After the power is supplied, the starting capacity will participate in the starting work. When the speed of the motor reaches 70% - 80% of the rated value, the centrifugal switch will automatically trip, and the starting capacity will be disconnected. The starting winding will not participate in the operation work, and the motor will continue to operate with the running winding coil. - In the second case, when the motor is still, the centrifugal switch is connected, and the starting capacity is involved in the starting work after the power is supplied. When the speed of the motor reaches 70% - 80% of the rated value, the centrifugal switch will automatically trip, and the starting capacity will complete the task and be disconnected. The running capacity is connected to the starting winding in series to participate in the operation work. This kind of connection was generally used in places with large and unstable loads such as air condensers, cutting machines, and woodworking machines. 3. ** Connection of the motor with different number of lead wires ** - ** 3 wires of AC 220V induced draft fan (motor as an example)**: First measure the values between the wires of the motor, such as red and blue resistance 381, red and yellow resistance 828, yellow and blue resistance 447. Since red and blue 381+ yellow and blue 447 = red and yellow 828, it can be judged that the starting winding has a high resistance (red and yellow wire) and the running winding has a low resistance (red and blue wire). Then connect the red and yellow wire to the capacity and the red and blue wire to the power supply. - ** Four wires of AC 220V motor (connection method)**: measure the value between each two wires respectively. For example, the resistance value of green and black is 0, the resistance value of red and black is 2.57, the resistance value of red and yellow is 0, and the resistance value of yellow and green is 2.65. The resistance value between green and black and red and yellow is infinite, which means that it is impossible. There are clear values between red and black and yellow and green, which means that there are two separate sets of winding and they are not connected. The yellow and black wires could be connected together as the common end, and the capacity could be connected to both ends of the red and green wires. The common end wire and any of the red and green wires could be connected to the power supply, and the motor with positive and negative rotation could be obtained. - ** AC 220V single-phase double-cap motor **: Pay attention to the selection of starting and running caps. The larger capacity was the starting capacity, and the smaller capacity was the running capacity. After the motor starts, the centrifugal switch disconnects the starting capacity from the circuit. If there is a lack of starting capacity, the motor will be difficult to start or unable to start (often manifested as normal no-load start, but unable to start after loading); if there is a lack of running capacity, the motor can start, but the output power will be reduced (often manifested as reduced load capacity). Generally, the starting capacity was connected in series to the starting winding of the single-phase motor and in parallel with the working winding. In addition, if the motor needs to be reversed, for the above-mentioned connection method, it is only necessary to swap the wires of the corresponding winding. In some cases, the 1 - 2 wire swap or the 3 - 4 wire swap can complete the reversal. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The method to detect the power of a single-phase motor is as follows: 1. ** Calculating power by measuring current and voltage: - An ammeter and a voltage meter were required. The ammeter and the voltage meter were connected to the input of the motor to obtain the correct current and voltage values. Then, the power was calculated using the formula: Power (W)= Current (A) x voltage (V) x power factor. 2. ** Using a power meter to measure **: - Put the power plug of the power meter into the socket, and put the power plug of the single-phase motor into the power socket of the power meter. - The load plug of the power meter was inserted into the load jack, and then the load plug of the single-phase motor was inserted into the load jack of the power meter. - Turn on the power supply of the single-phase motor, start the motor, observe the display screen of the power meter, and record the power value of the single-phase motor. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
For the choice of 15kW-single-phase motor, the first thing to do was to determine the type of the motor. Generally, the choice could be an Electrolyte or Metal Film Condenser, which was suitable for high-power single-phase motor. Then, through the formula,(C = I / (2 Pi f Delta V)/), where/(C/) represents the size of the capacity.(Unit is Farad [F]),[I] represents the current when the motor is running (Unit is Ampere [A]). According to experience, 1,000,000 volts is about 6A, and 15,000,000 volts is about [15×6 = 90A].[F] represents the frequency of the power supply (Unit is Hertz [Hertz]), and [Delta V] represents the difference between the rated voltage of the voltage and the power supply voltage (Unit is Volts [V]). At the same time, for the 1. 5kW-single-phase motor, the operating capacity should be 45 - 60uF, and the starting capacity should be 100 - 250uF times of the operating capacity. According to experience, the operating capacity of the 1kW-single-phase motor should be 30 - 40uF, and the starting capacity should be 2 - 4 times of the operating capacity. It can be used as a reference for the selection of the 15kW-single-phase motor. In addition, the voltage endurance value of the capacity is greater than or equal to 1.5 times the power supply voltage. Generally, 400V/450V is selected. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
There are several formulas for the matching of single-phase motor with the following: 1. Calculating the working capacity according to the power: \(GC = 1950I/U\cos_\)(microfarad),\(I_) is the motor current,\(U_) is the single-phase power supply voltage, and\(\cos_\) is the power factor (take\(0.75_)). If the single-phase power is taken as\(220Vdm_), then\(GC = 1950P/(U ^2)\cos_= 1950*P/(220*220)*0.75 = 0.03*P(uF), and\(P_) is the motor power. After calculating the working capacity, the starting capacity shall be taken as 1 - 4 times of the working capacity. 2. <<C = 2 <fL>/<^2>>, where <C> is the capacity of the transformer,<f> is the frequency of the power supply,<L> is the induction of the motor, and <<^2>> is the power factor. 3. When the transformer is damaged and the labeled parameters are unknown, it can be selected according to the calculation of C = 8fs (uF), where C is the matching capacity (unit is microfarad); J is the current density of the motor starting winding (generally choose 5 - 7A/square); s is the cross-section area of the starting winding wire (square). <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
For the measurement of the single-phase pump motor resistance, the following methods can be used: cut off the connection UA, and use a 1-ohm-block Multimeter to measure the starting winding U1 and U2. The resistance should be about 5 to 10 ohm-blocks. If the resistance value is greater than 1k, the winding will be burned out. Then, measure the main winding V1V2, and its resistance value is dozens of Ohms. Then measure the main and auxiliary winding U1V1, which should be infinite normally. If there is a resistance value, it means that the main and auxiliary winding has a short circuit phenomenon. After that, you need to check whether the charging and discharge of the capacity is normal. In addition, the normal resistance range of a single-phase motor is usually between 5 - 50 Ohms, and the specific range needs to be determined according to the motor model and power. You can use a Multimeter to adjust the resistance gear. The two leads of the motor can be connected to the two test pins of the Multimeter for testing. If the resistance of the motor is within the normal range, the reading of the Multimeter should be between 5 - 50 Ohms. If the resistance is abnormal, you should check whether the motor's transformer and starting circuit are normal. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The following methods can be used to measure the coil resistance of a single-phase motor: 1. ** Preparing Work ** - First of all, the single-phase motor's power supply was disconnected, and the voltage of the electric current was discharged to ensure safe operation. - Choose a suitable ohmmeter (Multimeter ohmmeter) and select the range according to the actual situation of the motor. 2. ** Measuring Operation ** - A single-phase motor usually leads out three wires, which can be marked as 1, 2, 3. Use the ohmmeter (when the power is low, the ohmmeter can be appropriately increased) to measure the three wires in pairs, namely, measure the three sets of resistance values of the wires. Under normal circumstances, the measured resistance was 1 large and 2 small. - You can also connect the two poles of the ohmmeter to the two winding terminal of the single-phase motor and record the measured resistance value. When measuring, the starting winding resistance of the single-phase motor should be measured first, and then the working winding resistance should be measured. When measuring the resistance of the starting winding, the working winding should be disconnected from the reactor. 3. ** Judgement of results and precautions ** - When the two sets of small resistance values are equal to the largest resistance value, it proves that the motor coil winding is normal; when the two sets of small resistance values are not equal to the largest resistance value, it proves that the motor is damaged. If the measured resistance is infinitely large, it proves that the motor winding is broken and damaged. - During the measurement, pay attention to the connection of the ohmmeter's poles to ensure that they are correct. At the same time, pay attention to the measurement accuracy to avoid excessive errors. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>