The contents
In each setting which requires running the motor in forward and reverse direction is always present magnetic starter the reversing circuit. The connection of such a component is not as difficult a task as it seems at first glance. In addition, the relevance of such problems appears quite often. For example, in drilling machines, cutting plants or elevators if it’s not domestic use.
The principal difference of this scheme from single is the presence of an additional control circuit and a slightly modified power section. For the implementation of such a switching installation is equipped with a button (SB3 in the figure). Such a system is usually protected from short circuit. To do this before the coils in the power circuit is provided having two normally closed contact (KM1.2 and KM2.2) derived from the contact of the consoles placed in the position of the magnetic contactors (KM1 and KM2).
In order for the scheme were readable, images of chain on it and the power contacts have a different color scheme. To simplify, here is not specified with a pair of power contacts, which are normally alphanumeric abbreviations. However, these issues can be found in articles dedicated to connecting standard magnetic launch systems.
A description of the stages of inclusion ↑
In the case of circuit-breaker QF1, at the same time all three phases adjacent to the power contacts of the contactor (KM1 and KM2) are in the same situation. In this first phase, which is the washing for the control circuit through the automatic protection of all control circuits SF1 and the power switch SB1 energizes the contact group under the third number, which refers to the buttons SB2, SB3. In this case
existing contactors (KM1 and KM2) to the contact under the acronym 13BUT acquires the meaning of duty. Therefore, the system is fully ready to work.
Excellent diagram, which clearly shows the mechanism of mounting elements shown in the photo below.
Switching system the reverse rotation of the motor ↑
Using the SB2 button, we will send a voltage of the first phase coil, which belongs to the magnetic starter KM1. After that there is the activation of normally open contacts and disconnecting normally closed. Thus closing contact KM1 is the effect of squatting starter. In this case all the three phases arrive at the appropriate motor winding, which in turn begins to create rotational movement.
Created scheme involves the presence of only one working starter. For example, can only work KM1 or KM2. In the above illustration you can see a diagram in which the engine is operating in a normal direction. The specified chain has real elements.
The change in rotational motion ↑
Now to give the opposite direction, you need to change the position of the power phases, it is convenient to do using the switch KM2.
All is due to the opening of the first phase. In this case, all contacts return to their original position de-energized the motor windings. This phase is a waiting mode.
The operation of the SB3 button actuates the magnetic contactor with the acronym KM2, which, in turn, changes the position of the second and third phase. This action causes the motor to rotate in the opposite direction. Now is the leading KM2 and until his open KM1 will not be involved.
Power circuits ↑
The picture below clearly describes the power circuits. In this position, the motor is normal rotation.
Now we see what happened transfer phase voltage and since the second and third phase difference, the engine acquired a reverse rotation.
In the pictures, where are the real elements you can see the connection scheme where the first phase marked in white, the second red and third blue color.
How is the protection of power circuits against short circuits ↑
As mentioned earlier, before performing the process of change of stage motion, stop the rotation of the engine. To do this, the system provides normally closed contacts. Because in their absence, inattention of the operator sooner or later would lead to the interface circuit, which would have occurred in the motor winding second and third phase. The proposed scheme is optimal, as it allows only one magnetic starter.
Conclusion ↑
The information provided may at first sight seem daunting. However, the provided diagrams and photos are a good example of solving such problems. Their study is guaranteed to ensure the success of the created system. Often in the beginning an example is the video course.
Since the information presented in the motion, has a much larger content and structural value.
Also, no harm will be familiar with the information, concerning the protection of the entire circuit of the electric motor, which will allow to create reliable systems.
