Husnen Rupani:
In this video, we will look at three direct online circuits for motor control with slight variations. Let’s get started.

Hi, I’m Hus. In this video, we will look at three direct online circuits. First one will be the standard DOL. Second one will be the DOL plus Jog. Third one will be DOL plus job operating two motors. For each of these, we will look at the circuit diagram first. We’ll identify the components and then connect and test the circuits. Let’s start with the first one.

Here’s our first circuit, which is the standard DOL. Here’s our three-phase motor. This is the contacts of our contactor, K1. This is our hold-in contact from K-1. Stop and start. So, the way this circuit will work, when the start push button is pressed, the current will go from L1 through stop through start to K1. And then K1.4 contact will close at the same time, giving us a hold-in contact. So, the current direction or current path will be through the hold-in contact and back to neutral. This will then keep this contact closed and our motor operating. Let’s connect the circuit.

For our DOL circuit, we will use this three-phase motor. We’ll use this contactor and this stop-start buttons. We’ll use this distro box for our power, which is connected to Portaphase so we can get three-phase extra-low voltage. Let’s start connecting the circuit.

Now that we have our control circuit connected, let’s test it before we connect the power. We can see that the contactor pulled in, so it’s energized and it stayed on. And now it’s turned off when I press the stop push button. Let’s connect the power wires and operate the motor.

Our first circuit is now complete. Let’s turn the power on and test the operation of the circuit and see how the motor operates.

We can see that the contactor pulls in and the motor turns. And when we press stop, eventually the motor stops. Let’s introduce Jog control into the circuit. Here’s our circuit number two with DOL and Jog control. Let’s identify all the components first. We still have our three-phase motor. We have our contacts from the contactor coil. We have our hold-in contact, stop button, start button. But we have something else here now and we’re going to use the selector switch to change the mode of operation from Jog and run.

Let’s see how the circuit will work. There are two modes of operation in the circuit. One of them is when this selector switch is in on mode or when it’s turned on. In which case we will basically have a holding circuit like this, so that will work like a normal DOL circuit. So, that will be our run mode.

So in that case, when the start button is pressed, the current will go from L1 through stop, through start to K2. K2 contact will close. Since this is already closed, we will have the complete hold-in circuit, which means the current flow will go through the hold-in, through the coil and then back, which will maintain these contacts and maintain the motor.

When this is turned off or in Jog mode, what’ll happen is every time we press the start button, the current will go from L1 through stop, through start, through K2, and then back, which will close these contacts. But since this is disconnected, the hold-in will not maintain, which means the motor will only operate while we press the start button, which is going to be our Jog button in this case.

Let’s connect the circuit. Rather than making the circuit from scratch, I’m going to introduce this selector switch in this mix. So, I already have a stop-start. I already have the contactor and the motor, everything wired. I’m just going to turn off the power. And I’m going to introduce this selector switch based on my circuit.

Let’s test the operation of this circuit, but we’ll start with just testing the control circuit and then we’ll turn on the power circuit after we’ve confirmed that it operates as expected.

As we can see, the start button is now working like a Jog circuit because the selector switch is in the Jog mode. If I turn it into run mode, we can see that now the contactor is holding in. So, we know that this circuit works. Let’s turn the power on. And turn it back [inaudible 00:05:22]. Contactor holds in, the motor is spinning. Stop it, turn to Jog, press the Jog button, let it go. Motor turns on momentarily and it stops. And that’s our DOL plus Jog circuit.

Let’s introduce a second motor into the mix and control two motors with this circuit.

This is the circuit will connect now. As you can see, this is still a DOL with Jog, but all we’ve added is another contactor and another motor and another coil that will control these contacts.

Let’s connect this circuit. Since I only have one motor in this box, I will introduce another box, which will be the motor starter Pracbox, which is designed to work with control circuit Pracbox so we can have two motors at the same time. Here’s the motor starter Pracbox and we have our second motor here. Now, unlike the motor in control circuit Pracbox, we have six terminals. This one only has three, so it’s already in Delta. So, all we’re going to do is introduce a second contactor and connect it to this motor and then test the operation.

All right, our circuit is ready. So, our DOL plus Jog was still there. We just added another contactor and the motor. Let’s turn the power on, and switch our mode to run mode and turn that on. We can see that motor is turning and this motor is turning as well.

If we flick to Jog mode, we can see both motors turn off. And if I then use the start button, which is now our Jog button, we can see that the motors turn on for a very short time. And that’s our DOL plus Jog with two motors.

I hope you enjoyed this video of direct online circuits for motor control. If you have any questions or feedback, please feel free to contact us. Thanks for watching.