AC Contactor Interlock Control Positive and Negative Rotation Operation
The following are the practical steps of the AC contactors 'interlocked control: ** I. Preparing Work ** 1. Required electrical components: - Two AC contactors (KM1 and KM2). Choose the appropriate specifications according to the motor power. - Heat relay (KH), used for overload protection. - Circuit Breaker (QF), controls the switching of the circuit and provides short-circuit protection. - Start button (Forward Rotation SSB2, Reverse Rotation SSB3) and Stop button (SSB1). - Fuse (FO), for short-circuit protection. 2. Checking the electrical components: - Make sure that the contacts of the AC contactors are flexible and free from stagnation. - The setting value of the thermal relay was adjusted according to the rated current of the motor. - The normally open and normally closed contacts of the button were normal. ** 2. Circuit Connection (Main Circuit)** 1. Power connection: - The circuit breaker QF is connected from the three-phase power supply (L1, L2, L3). - When KM1 is working (forward rotation), the main circuit is connected in the order of L1 - L2 - L3, that is, the power supply supplies power to the motor M through QF, KM1 main contact and thermal relay KH, and the motor runs in the forward direction. - When the KM2 was working (reversing), the connection sequence became L1 - L3 - L2, and the order of L2 and L3 was exchanged through the KM2 to realize the motor reversal. 2. Connection to the motor: - The three-phase winding of the motor was connected to the output end of the thermal relay KH. ** 3. Circuit Connection (Control Circuit Part-Electric Interlock)** 1. First, connect to the public part: - Connecting a neutral wire to the thermal relay's normally closed terminal 95, then connecting a wire from the terminal 96 to the forward (km1) AC Contactor's terminal A2, and then connecting a wire from this terminal to the reverse (km2) AC Contactor's terminal A2. - From the live wire end, connect a wire to the fuse, and then connect a wire from the fuse to the stop button terminal 11 (normally closed for the STB3). 2. Forward Rotation Control Circuit Connection: - When the start button for forward rotation is pressed, the current passes through the thermal relay auxiliary contact KH1 - 2, 3, 4, 5 - 6, and reaches the KM1 coil to complete the start. KM1 pulled in, and at the same time, KM1 - 1 auxiliary contact closed to replace the pressing action of the SSB2 button, completing the self-locking. Moreover, the normally closed auxiliary contact of KM2 should be connected in series with the coil circuit of KM1. In this way, when KM2 is working (reversing), its normally closed contact will be disconnected to prevent KM1 from being accidentally energized. 3. Reverse Control Circuit Connection: - When the reverse start button SSB3 is pressed, the current passes through 1, 2, 3, 4, 9, and 10 to the KM2 coil to complete the reverse start. At the same time, the KM2 - 1 normally open contact is closed to achieve self-locking. At the same time, the normally closed auxiliary contact of KM1 is connected in series with the coil circuit of KM2. When KM1 is working (when it is rotating forward), its normally closed contact is disconnected to prevent KM2 from being powered up by mistake. ** 4. Inspection and Testing ** 1. Line inspection: - Check whether all the connecting wires are firm, loose or short-circuit. - Confirm that the electrical interlocked connection is correct, that is, the normally closed auxiliary contact of KM1 is connected in series in the coil circuit of KM2, and the normally closed auxiliary contact of KM2 is connected in series in the coil circuit of KM1. 2. No-load test: - Close the circuit breaker QF, press the forward start button SSB2, and observe whether the AC Contactor KM1 is pulled in and whether the motor is rotating forward. - Press the stop button, and the motor should stop rotating. - Press the reverse start button SSB3 and observe whether the AC Contactor KM2 is pulled in and whether the motor is reversed. 3. Load-testing (after ensuring that the no-load test is normal): - Connecting the motor load, repeating forward, reverse and stop operations, checking the operation of the motor under load, and paying attention to whether the thermal relay is working normally to prevent the motor from overloading. Read more exciting novels for free
Diagram of Positive and Negative Rotation Circuit for Electrician Operation
The circuit diagram of the motor consists of two parts: the main circuit and the control circuit. Principle of the main circuit: After the three-phase power supply passes through the fuse, it is divided into two paths to the main contacts of the two contactors. The phase sequence of the main contacts of the contactors corresponds to the power supply. The main contacts of the two contactors were connected in parallel after being swapped, then connected to the thermal relay, and finally connected to the motor. For example, when the KM1 main contact is connected, the power supplies L1, L2, and L3 flow to the first phase, the second phase, and the third phase of the three-phase motor respectively, and the motor is rotated in the forward direction; when the KM2 main contact is connected, the power supplies L1, L2, and L3 flow to the third phase, the second phase, and the first phase of the three-phase motor respectively, and the motor is rotated in the reverse direction. By controlling the main contacts of the contactors 1 and 2 to turn on and off, the forward and reverse rotation of the motor can be realized, and to control the main contacts of the contactors, the coil needs to be controlled. Also, it should be noted that the main contacts of contactors 1 and 2 cannot be closed at the same time, otherwise the power supply will be short-circuited. Control circuit principle: 380V single-phase voltage is converted into 36V safety voltage through a transformer to supply power to the control circuit. The 36V power supply first passed through the thermal relay and the stop switch, then reached the forward button, reverse button, and the normally open KM1 and KM2 respectively. If the forward rotation button SSB1 is pressed, the current will reach the KM1 coil through the normally closed SSB1 and KM2. At this time, the KM1 coil will be energized, and the KM1 main contact will be connected to the motor for forward rotation. At the same time, the KM1 is normally open to connect both ends of SSB1 to realize self-locking, and the KM1 is normally closed to prevent the reverse button SSB2 from being short-circuited by mistakenly pressing it. When the stop button SSB3 is pressed, the KM1 coil is cut off, the KM1 main contact is disconnected, and the motor stops running. The KM1 is normally open and loses its self-locking. If the reverse rotation button SSB2 is pressed, the current will reach the KM2 coil through the SSB2 and the KM1 normally closed. At this time, the KM2 coil will be energized, and the KM2 main contact will be connected to the motor to rotate in reverse. At the same time, the KM2 will be normally open to connect both ends of SSB2 to realize self-locking, and the KM2 normally closed and disconnected will prevent the forward rotation button SSB1 from being pressed by mistake to short circuit. When the stop button SSB3 is pressed, the KM2 coil is cut off, the KM2 main contact is disconnected, and the motor stops running. The KM2 is normally open and loses its self-locking. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Using r instruction to program the control of the positive and negative rotation of the motor
The following is the general idea of programming the motor reverse rotation control based on the S (set) and R (reset) commands: ##I. I/O allocation 1. ** Entering Device ** - A stop button (such as I0.0) is required to stop the operation of the motor. - Forward rotation button (for example, I0.1). When this button is pressed, the motor will start in the forward direction. - Reverse button (e.g. I0.2), press this button to start the motor in reverse. 2. ** Outputting Device ** - Forward Contactor (e.g. Q0.1), used to control the opening and closing of the forward circuit of the motor. - Reverse Contactor (such as Q0.2), which controls the connection and interruption of the motor reverse circuit. ##2. Program logic 1. ** Forward Rotation Control Logics ** - When the Forward Rotation button (I0.1) is pressed, use the S command to set the Forward Rotation Contactor (Q0.1), and the motor starts to rotate forward. At the same time, in order to prevent the forward and reverse rotation from running at the same time, it was necessary to use interlocked logic. That is, when Q0.1 is set, the logic of the normally closed contact Q0.1 is inverted and then connected in series with the reversal control logic to ensure that the reversal contactors (Q0.2) cannot be energized. - When the stop button (I0.0) is pressed, use the R command to reset the forward rotating contactors (Q0.1), and the motor stops rotating forward. 2. ** Reverse control logic ** - When the reverse button (I0.2) is pressed, use the S command to set the reversing contactors (Q0.2), and the motor will reverse. Similarly, when Q0.2 is set, the logic of the normally closed contact Q0.2 is inverted and connected in series with the forward rotation control logic to prevent the forward rotation contactors (Q0.1) from being energized. - When the stop button (I0.0) is pressed, the reversing contactors (Q0.2) are reset through the R command, and the motor stops reversing. The following is a simple ladder diagram example (described in a programming style similar to the ladder diagram of a PC): ###(I) Forward Rotation |--I0.1 (Forward Turn button)--|S|--Q0.1 (Forward Contactor)--| |--Q0.1 (normally closed)--||--I0.2 (Reverse button)--|(Interlocking logic) |--I0.0 (stop button)--|R|--Q0.1 (Forward Contactor)--| ###(2) Reverse Part |--I0.2 (Reverse button)--|S|--Q0.2 (Reverse Contactor)--| |--Q0.2 (normally closed)--||--I0.1 (Forward Turn button)--|(Interlocking logic) |--I0.0 (stop button)--|R|--Q0.2 (Reverse Contactor)--| In this way, the positive and negative rotation control programming of the motor could be realized through the S and R instructions and the interlocked logic. In actual programming, it was also necessary to consider the protection mechanism of the motor, such as overload protection, and make appropriate adjustments according to the specific model of the PC and the programming environment. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Positive and negative rotation and centrifugal drying
Positive and negative rotation and centrifugal drying were functional concepts involved in some household appliances, such as washing machines and washing machines. In terms of drying, centrifugal drying was a method of drying at room temperature by rotating the brush. For example, in the centrifugal drying of the washing machine, the rolling brush used the centrifugal force to throw out the water during the rotation process to achieve the purpose of drying. It was relatively energy-efficient, and it was not easy to dry the stains on the roller brush. However, due to the room temperature environment and the narrow space between the roller brush and the base, the drying effect might not be ideal. After a long time, there might be a problem of moisture and odor. The reversing function was also used in washing and drying equipment. For example, when washing and drying clothes, the reversing function of the roller brush or the inner cylinder could make the washing or drying more uniform and sufficient. In the aspect of drying clothes, it can allow all parts of the clothes to get better hot air circulation or dehydration treatment during the drying process, which helps to improve the drying efficiency and drying quality, reduce the wrinkles of the clothes, and help to better remove stains during the cleaning process. In the cleaning of the roller brush of the washing machine, the positive and negative rotation technology helps to prevent hair entanglement, and it can make all parts of the roller brush have a better cleaning effect during self-cleaning. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Illustration of the positive and negative rotation of the generator
The following is some information about the positive and negative rotation of the generator: ** 1. Three-phase AC motor (related to the principle of the generator), positive and negative rotation principle ** 1. ** Relationship between phase order and rotating magnetic field ** - The order in which the three-phase AC power supply reaches its maximum value is called phase sequence. The rotating magnetic field of the three-phase AC motor depends on the phase sequence of the three-phase AC power supply connected to the motor's winding. The phase sequence determines the direction of the rotating magnetic field of the motor's winding, and thus determines the direction of the motor's rotation. - For a three-phase alternating current motor (the principle of a generator is similar), as long as the phase sequence of two of the power sources is arbitrarily reversed, the direction of the rotating magnetic field will be reversed. For example, in the classic relay control circuit of the contactors, two contactors could be connected, one in positive sequence and the other in negative sequence, to achieve positive and negative rotation of the motor (similar to the generator). 2. ** 220V miniature household generator positive and negative transfer line diagram (take reverse switch control as an example)** - ** Diagram composition ** - It included a motor body, two ports for the incoming and outgoing lines, and a control switch. The control switch had three contacts: C (normally closed contact), O (normally open contact), and L (coil contact). In the stopped state, the C and L contacts were connected, and the O and L contacts were disconnected. - ** Principle of Forward and Reverse Rotation ** - When the switch was turned to one side, it connected the C and L contacts, and the current flowed through the motor, making it run forward. When the switch was turned to the other side, it connected the O and L contacts, and the motor would run in reverse. During operation, the incoming and outgoing wires needed to be correctly connected to the corresponding positions in the junction box, and the coil interface of the motor was connected to the L contact of the junction box. At the same time, the C, O, and L contacts of the control switch were connected to the corresponding interface in the junction box. 3. ** Positive and negative rotation control using the cement production line motor control principle diagram as an example (similar to the generator control principle)** - There are two AC contactors. For example, when QC1 is energized, the motor will rotate forward, and when QC2 is energized, the motor will rotate backward. This was achieved by changing the phase sequence of the two wires. Two buttons in the control circuit are connected by dotted lines to form a button interlocked circuit, and two auxiliary normally closed contacts of the AC contactors form an interlocked circuit of the AC contactors. In addition, there is a limit switch used to automatically cut off the power supply when the motor reaches the limit. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Positive and negative rotation of the membrane measuring pump
Most types of membrane type measuring pump do not have clear requirements for steering. Some types of pump may cause adverse effects on gears, turbine, and worm when reversing. There will also be noise and vibration during operation. It is recommended to confirm with the manufacturer whether there is a clear steering requirement. If there is no clear regulation, there is no need to consider the steering problem. However, there were also measuring pump's motor that could only rotate in the forward direction. If it was rotated in the reverse direction for a long time, it would damage the transmission mechanism. From the rear end of the motor, the rotation direction of the motor was clockwise. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
What is the reason for the alternating positive and negative rotation of the motor?
the practical application of that delay positive and negative rotation of the motor
The delayed positive and negative rotation of the motor had applications in many practical scenarios: 1. ** Large washing machine **: It can use a positive and negative automatic controller to control the motor to achieve the positive and reverse functions. The reversing automatic controller was a double-pulse delay relay, suitable for control circuits with an AC of 50HZ and a rated voltage of 380V and below. It controlled the motor to rotate forward, stop, and reverse according to the predetermined time. There were two common models with a fixed stop time for forward and reverse rotation (such as 25 seconds for forward rotation, 5 seconds for stop, and 25 seconds for reverse rotation), and an variable stop time for forward and reverse rotation (forward rotation, reverse rotation, and stop can be set within 1 - 15 minutes). 2. ** Mechanical Equipment Control **: The delayed switching of the forward and reverse rotation of the motor is often used to control mechanical equipment. It can use the motor forward and reverse control module, which is composed of a power supply module, a control module, and a motor drive module. After connecting the power supply, the motor, and the control module and setting the parameters of the control module, the automatic switching of the positive and negative rotation of the motor and the delay control could be realized. It was also possible to use a single-chip computer to control the forward and reverse rotation of the motor. First, the motor drive module was connected to the single-chip computer controller, and then the control program was written. This could achieve more flexible control, and the control program could be designed according to needs. When switching between the positive and negative rotation of the motor, the following techniques should be paid attention to: - ** Setting of delay time **: Set it according to the equipment requirements, usually 1 - 5 seconds, to ensure the stability and safety of the equipment. - ** Selection of the motor drive module **: Consider the parameters such as the motor power and voltage to ensure the accuracy and stability of the motor's forward and reverse rotation control. At the same time, pay attention to the quality and reliability of the motor drive module to ensure the long-term stable operation of the equipment. - ** Controller's reliability and stability **: The controller is the core part, and its reliability and stability affect the operation and safety of the equipment. The quality and reliability should be taken into consideration when choosing, and it should be fully tested and verified. 3. ** Control of specific actions in the motor control **: For example, when controlling the stepping motor, press the start switch to trigger the cylinder to push out and maintain for a certain time (such as 2s), and then the motor will rotate forward. When it touches the sensor, it will slow down and stop. When the motor stops, it will trigger the cylinder to retract and maintain for a certain time (such as 3s), and then the motor will rotate backward. When it touches the sensor, it will stop urgently. This involved the use of multiple instructions, including adding wait for input instructions, triggering output instructions, delaying wait instructions, and so on. 4. ** Three-phase motor positive and negative transfer wire control **: The positive and negative transfer wire of the three-phase motor can control the positive and negative rotation of the motor by pressing the forward or reverse button, using the buttons, coil, and normally closed contacts in different circuits. During this process, a certain delay can be set through the relevant control circuit. 5. ** In some conventional control scenarios of the motor, such as using a delay relay to realize the functions of the motor's timed start, stop, and forward and backward rotation control. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
How to connect the positive and negative rotation of the motor with a timer?
Taking a three-phase motor as an example, a positive and negative rotation control circuit with a timer was as follows: First of all, there are contactors in the circuit. When the main contact of the KP contactors is closed, the motor will rotate forward. When the main contact of the KP contactors is closed, the motor will rotate in reverse. This is because changing the phase sequence of the three-phase motor will change the direction of the rotating magnetic field, which will cause the direction of the motor rotation to change. In this circuit, the timer played the role of controlling the forward and reverse switching time of the motor and the rest time. Take the power-on delay time relay as an example. Suppose you press the forward start button (such as sb2) first, kme will attract and self-lock to make the motor rotate forward. At this time, the timer kt1 will start to power-on and delay (for example, set five seconds). After five seconds, the contact of kt1 will move, open and close, making km2 attract (km1 release). The motor will switch to reverse direction. At the same time, km2 attracts and makes the kt2 coil receive electricity and start to delay (assuming it is also five seconds). After five seconds, the electric shock action of kt2 will be disconnected, km2 will release, and the motor will stop. Then, the timer kt1 was powered up again and delayed. After the time was up, km1 pulled the motor forward again, and so on. In the actual connection, attention should be paid to the connection order and interlocked relationship between the various components. For example, the positive and negative rotation interlocked to prevent the two contactors from short-circuit and other faults caused by the simultaneous attraction. At the same time, it was also necessary to consider the power transmission, self-locking, control logic and other factors of the circuit. However, this was only a basic principle of a motor with a timer. The actual application scenarios were different, and the circuit might be more complicated and required to follow electrical safety regulations for wire operation. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
Can a single-phase motor have positive and negative rotation?
Not all single-phase motor could achieve positive and negative rotation. For example, shaded pole motor, submerged pump motor, etc., due to their special use, although some of them had a capacity, they would be modified during use, such as adding one-way bearings, reversing sleeves, etc. These motor could not rotate forward and backward. In principle, double-capacity and single-capacity motor could achieve positive and negative rotation. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>
The Method of Analyzing the Cause of the Alternation of the Positive and Negative Rotation of the Electromotor
To analyze the reason for the alternating positive and negative rotation of the motor, the following methods can be used: 1. * * Check the internal parts of the motor ** - Check whether there is a short circuit or an open circuit in the motor's winding, which can be detected by the relevant electrical test instrument. If there was a fault in the winding, it could affect the magnetic field and the direction of the current, causing the motor to rotate in both positive and negative directions. - Check the degree of wear of the brush. If the brush is seriously worn, it may cause the working state of the motor to be unstable, thus affecting the direction of the motor. - It was necessary to measure whether the resistance of the motor was normal. An abnormal resistance of the motor could cause the motor to run abnormally, resulting in alternating positive and negative rotation. 2. * * Investigate external interference factors ** - Observe whether the power supply voltage is stable. Unstable power supply voltage may cause the motor to rotate in both positive and negative directions. A voltage meter can be used to monitor the power supply voltage. - Consider whether the motor and other equipment affect each other. If there is electromagnetic interference or electrical connection problems between the motor and other equipment, it may cause it to alternate forward and backward. 3. * * Observe the running state of the motor ** - Pay attention to whether there is any strange noise or vibration when the motor is working normally. These abnormalities may indicate that there is an internal fault in the motor or external interference, which is the potential cause of the alternating positive and negative rotation of the motor. <a href="/?from=ask_words" style="color:red" target="_blank">Read more exciting novels for free</a>