Husnen Rupani:
In this video, we will connect the Star Delta Starter Circuit for motor control. Let’s get started. Hi, I’m Hus. In this video, we will connect the Star Delta Starter Circuit using the Control Circuit Pracbox. First, we will look at the circuit diagram and then identify the components and then connect the circuit and test it. Let’s start with the circuit diagram. This is the circuit diagram that we’ll connect today. A quick disclaimer, as you might notice, I haven’t covered all the safety aspects of the circuit. I’ve just made it functional. Let’s identify all the components that we’re going to use in this circuit. Let’s look at the power circuit of this circuit diagram. We have our three-phase motor with six terminals. We have our K1 contactor contacts, which is coming from K1 coil. We have our K3, which is our delta. That’s here. And we have our K2, which is star, and that’s here.

We also have our “stop” button, “start” button and the on-delay timer. And the on-delay timer has two contacts normally closed and normally open contacts. Let’s understand how the circuit will work. When the start button is pressed, the current will go from L1 through “start” and “stop” push buttons to our on-delay timer, which will start the timer. At the same time, it will go through this branch here, which will then turn on K2 coil and close these contacts. As soon as the K2 coil is energized, this contact will close, which will allow the current to go through to our main contactor K1 and that will close our contacts here. This will then put our motor into star formation. So the motor will start turning at this point. While the motor is turning, the timer is counting down. While the timer is counting down, we have this branch turned on and since we have this contact as normally closed, we have that as our interlock.

As soon as this timer finishes counting, this contact will open. When this contact opens, the K2 will de-energize. When the K2 de-energizes, this contact closes. At the same time, this contact will close as well, which will allow the current to go through here and that will energize our delta coil and close these contacts here. Our K1 is already on through this branch, which will have these contacts closed, so now our motor has switched to delta. Let’s identify the components on the Control Circuit Pracbox that we’re going to use for this circuit. On the Control Circuit Pracbox, we will use this motor. We have six terminals for this three-phase motor. We will use this start and stop station here. We’ll use this timer for our on-delay timer. It’s already programmed for three seconds.

This is going to be our K1, which is our main contactor, K2, which is going to be our star contactor and K3, which is going to be our delta contactor. We will use porta phase as our supply, so we’ll use this distribution box. We have L1, L2, L3, and neutral. Let’s connect the circuit. As I connect the circuit, I will also mark off the wires that are connected so I can keep a track of my circuit. Before we proceed to connecting the power circuit, let’s test if our control circuit works. So I’ve turned on the power. Let’s turn the start button on and let’s look at the status of these coils here. We can see that these two coils turn on, which is our K1 and K2, and as soon as the timer finishes, our K3 comes on. So we know that our control circuit works as expected. Let’s connect the power circuit and see if the whole circuit works as expected. Our circuit is now complete. Let’s test the whole operation.

So I’ll turn the power on and I’ll press start. We can see that these two contactors came on, the motor is turning and after three seconds, the delta contactor turns on. To prove that it is working as expected, we will also measure current on one of the lines to see how the line current changes when it goes from start to delta. Let’s stop it. We’ll use our clamp meter for this and we’ll measure the current in line one of the red. So right now we’ve got nothing. Turn that on, we have a current of about 68 milliamps. As it switches over, the current goes to 116.5 milliamps. So we can say that the operation is working as expected. I hope you enjoyed this video of Star Delta Starter Circuit. If you have any questions or feedback, please feel free to contact us. Thanks for watching.