00:03This video will simulate a reversing function for a three-phase motor.
00:09Interlocking by auxiliary contact. This allows for interlocking at a specific moment when the user changes.
00:14His preference is for the directional rotation of a three-phase motor. For this, we have
00:18the power supply lines, lines 1, 2, 3, neutral and protection.
00:46The power circuit consists of a circuit breaker, two contacts, and a thermal relay.
00:57protection and a three-phase motor.
01:21We make the parallel connection of a three-phase contact to another that is normally open.
01:28This system, as its name indicates, reverses the rotation of a motor, and this effect is achieved
01:33by changing the magnetic field generated by the coils in the stator, so that the rotor
01:37It tends to follow it and turn in the opposite direction. To achieve this effect, simply reverse.
01:45Two phases, any of the three-phase lines that supply power to the motor. At an industrial level
01:50We found some elements that perform this task, using a single device, but
01:55Working with electromagnetic control. Now we change the names of the elements
02:09The triple contact will be named C1, and the triple contact 2 will be named C2.
02:20The thermal relay will be named F1.
02:25The control circuit consists of two contacts, a thermal relay, and a normally closed push button.
02:32two normally open pushbuttons, three indicator lights, for stop and start.
02:38It should be noted that the two contacts cannot be activated at the same time, because that would cause
02:44a short circuit between the phases, so both contacts must be interlocked, so that
02:48When one is activated, the other is deactivated, and vice versa.
02:55Three-phase asynchronous motors are used in a wide variety of industrial applications.
03:01To move part of a machine tool, to raise and lower a winch to lift or lower a
03:06Loading, or moving a bridge crane back and forth, are just some of the applications we can
03:11It is very important to take precautions when you are in the workplace.
03:18appropriate to prevent a short circuit, preventing both contacts from entering the same circuit.
03:23time. Therefore, we must interlock the contacts to prevent them from entering at the same time and make
03:29Use of dual-chamber pushbuttons as a safety measure. Dual-chamber pushbuttons
03:34They have two associated auxiliary contacts, one normally closed and one normally open.
03:45In case we need to stop the engine, in real life after it has been disconnected we can
03:50inject rectified direct current into the motor stator for the necessary time, thus
03:55This generates a magnetic field that slows the motor. The value of the current to be injected,
04:00As a guideline, it will be 1.3 times the nominal operating value.
04:22Now we will proceed to make the connection, which, as reiterated, the two contacts cannot
04:27activate at the same time because it would cause a short circuit between the phases, so
04:32Both contacts must be interlocked so that when one is activated, the other is deactivated.
04:36vice versa.
05:02Now we change the names of the elements, for the normally closed thermal relay contact,
05:07F1 will be the normally closed push button, S0 for the normally open push button
05:20It will be S1, the coil is named as C1, and the running light as H1, for the first interlock
05:41The direction of the motor, its open contact will be called C1.
05:54We also have another normally open push button, S2,
06:02C2, whose interlock will be named as C2, this in series to a closed contact C2,
06:10This activates a coil C2,
06:20to the parallel connection of another running light called H2.
06:30The thermal relay will always activate in the event of an overload, regardless of the direction of rotation at that moment.
06:37Its name will be F1.
06:43In the simulation, the operating cycle is, when S1 is pressed, coil C1 is energized,
06:49self-supporting, at the same time its closed auxiliary contact opens, blocking the C2 coil,
06:54so that if S2 were pressed it would not be possible to energize it.
06:58If S2 were pressed while coil C1 was energized, it would not be possible to energize coil C2.
07:05because its circuit has opened at DC1.
07:21That's all well and good. If you find it useful, don't forget to subscribe.
07:29Thank you!
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