Hi, I’m Hus. I am the CEO of Infinispark. I have more than 12 years of experience in the electrotechnology training industry. So I understand the concerns of compliance, learner attrition and the increasing demands on trainers time. Welcome to the AC Pracbox video. In this video, I will show you how the AC Pracbox will simplify maintaining compliance, how it will increase your learners engagement by bridging the gap between theory and prac, how it will empower your trainers to explain complex concepts very quickly. Towards the end of the video, I will show you the AC Pracbox in action and use it to demonstrate the difference between Star and Delta connections using the lamps. Please stay tuned for that.

The AC Pracbox is designed for G102, which is now replaced by L20 in the new training package. This is one of the core units of certificate three of electrotechnology. All the components in this equipment are chosen from the range statement or range of conditions of the unit of competency. The AC Pracbox covers 99% of the practical activities required in the performance criteria and the performance evidence of this unit. Since the practical training is aligned with the training package, it will avoid the risk of being noncompliant. Overall, it covers 92% of this unit where there is 1% performance gap and 7% knowledge gap. AC theory is perhaps the most difficult subject in the cert three of electrotechnology, mainly because of the number of calculations and theory it has.

The biggest problem is the gap between theory and practical because of the lack of appropriate equipment and time, the result is disengaged learners. The AC Pracbox has the relevant components required to close that gap. Almost every concept they learn in theory can be demonstrated and assessed with the AC Pracbox. In my experience, we were able to increase the prac hours by at least 200% with room to grow. The students loved how after every theory class they saw the practical application model. We also offer 30 practical exercises, including marking guides as an add-on to enhance your students’ learning experience. By providing the relevant equipment, you will empower the trainers to explain complex theories more easily and quickly. Let me show you the components they will have access to in the AC Pracbox.

In the AC Pracbox, we have various power resistors. So on this side we have power resistors going from five ohms, 10 ohms, and 20 ohms, and they’re all 50 watts. And on this side we’ve got 100 watt power resistors that you can use for Star and Delta Connection with three-phase. They’re all the same values. So you can have balanced circuit and if you can combine one of these resistors with these, you can have an imbalance in the circuit as well. On this side, we’ve got contactor coils that we’ve connected as inductors. So if you notice this inductor here, the core is connected to the other, that means there is no air gap. But in this bottom one and the top one there is a slight gap between the core and that is causing the inductors to change. So that’s how we’ve made these contactor coils as inductors.

On this side we’ve got capacitors. So we’ve got three paper film capacitors. One electrolytic non-polarized capacitor and a motor start capacitor and a power factor correction capacitor. All different values, 22 microfarads, 220, microfarads, 53 microfarads, and 80 microfarads. On this side, we’ve got three button holders where you can connect these lamps. Now these are 42-volt lamps, so they’re not your standard 32 or 24-volt lamps that you will see in the training, but 42 volts. The benefit of that, you will be able to connect these lamps in Star and Delta without worrying about damaging them. And right here in the middle we’ve got some toggle switches, which you can use for controlling the lines that are coming in. So if you’ve got three lines in a neutral, you’ve got four toggle switches for that. And the highlight of this box is this meter here.

This meter measures power, voltage, current, power factor, frequency and energy all in one place so you don’t have to get a separate meter that will do power factor or a separate multimeter that will do voltage and current and so on. All can be done just from here. So very powerful. Innovations like the real inductors used here make it extremely easy to explain power factor and power factor correction concepts. The meter used here is so versatile that it shows all required measurements in one place in a small package, and just the ability to visually experience the difference between Star and Delta connections will take the student’s learning experience to the next level. Let me show you some of these complex theories in action.

I’m going to show you a demo of power factor of various components. But before we start, AC Pracbox doesn’t have its own power supply, so you will have to provide AC power for it. In our case, we’re using Portaphase, which is a single to three-phase extra low voltage power supply, which sends the power from the main unit to the distro box and then from here, we have an option of having either a variable single-phase output or a fixed three-phase output. Let’s start with the variable single phase and do our first demo. So now I’ve connected the distro box to the AC supply. Let me turn this on. So I’ve turned the Portaphase on, and when I turn the single phase on, I can see the voltage here. So at this stage, we’re getting 15 volts AC coming from the distro box.

So I’m going to start by powering up one of the resistive components. So we’ll start with the 20 ohm resistor. So the output of the meter is connected to 20 ohm resistor, and we can see that we’ve got power of 6.2 watts and the power factor is one, which means it’s a resistive component. So all resistive components have a power factor of one, so we can see that clearly here. Let’s change that component to a capacitive component and we’ll use this 80 microfarad capacitor here. And when I do that, if you notice the power factor is showing zero. Power, P is also zero watts or 0.1 watt, but if you notice, it’s still drawing current, which means that it is drawing power, but it’s not any useful power, it’s the reactive power.

Let’s go to an inductive component now. So if I connect 18 ohm 92-millihenry inductor, I can see that I’ve got a power factor of 0.54. I’m drawing a little bit of current, I’m using the power as well, 2.7 watts of power. So that shows that a resistive component has a power factor of one, capacitive component close to zero, an inductive component that has part of resistive component. We have a power factor somewhere between zero and one. So this gives a good idea to students how various components react to AC power.

Let me show you a demo of power factor correction. So we’ll use this inductor 18-ohm, 92-millihenry inductor as our load. So our supply is still 15 volts connected to the distro box, that shows 15 volts there. I’m connecting the output of the meter to our inductor. Now remember, the inductor has some resistive component that’s 18 ohms and some inductive components that’s 92 millihenry. And because of that we get a power factor that’s between zero and one. In this case, we’re getting 0.54 or 0.55. The voltage dropped a little bit, so I’m going to crank it up back to 15 volts. Okay, so now we have 15 volts power that this component is using at the moment is 3.6 watts. It’s drawing 0.43 amps of current. Power factor is 0.55. Let’s try and improve the power factor of this component, starting from smaller improvement and leading towards bigger.

So I’m going to use a 22 microfarad capacitor to improve the power factor. Right now, power factor 0.55, including a 22 microfarad capacitor, the power factor went to 0.67. All right, so that is an obvious improvement there. If you notice the true power hasn’t changed and that’s what happened. So true power doesn’t get affected much by the capacitors because all the capacitor is doing is counteracting the inductive part of the load. If I increase my capacitance to 80 microfarad, let’s see what happens. So it went from 0.67 to 0.96. Right, so a massive increase, very close to one. That means that’s a very good power factor correction. But what would happen if I go beyond that? Now after 80 microfarad, we’ve got a 220 microfarad capacitor. Let’s connect that and see what happens.

So right now it’s showing 0.56, improving it with 220 microfarad. It’s showing 0.44. The current was about 400 milliamps. It’s now showing 700 milliamps or 740 milliamps. The reason for that is, we have over corrected it, which means we’re now in a leading power factor. Without the capacitors, we were in lagging power factor, and as we add capacitors, it was getting closer and closer to one. When we went overboard with our power factor correction, we’re now in the leading power factor so that’s counteracting everything we’re doing.

Let’s now look at the comparison between Star and Delta connection visually using the lamps. So I’m going to put these lamps. The AC Pracbox comes with 42-volt lamps. Okay, let’s connect the three-phase. Again, the three-phase is coming from the distro box, which is connected to the Portaphase. So we’re getting ELV power. L1, L2, L3, and neutral. So now we have the four wires coming from the distro box connected to these toggle switches. All the toggle switches are at the moment in on position and we’ll now connect them to the lamps. So we’ll go to the first lamp. So the red phase is going to lamp one, white phase going to lamp two, and the blue phase going to lamp three. Let me start by connecting this in a Star Connection first.

So for Star, I have to create a bridge on the other side of the load. So now I have a Star point here. I’m going to extend this Star point to the neutral, just so my neutral is connected. Now if I turn these on, we can see that the lamps are turning on. I can measure the voltage across these lamps as well. So let’s measure the voltage across these lamps to see what we’re getting. So I’ve set this up to voltmeter reading. Okay, changing it to AC. So we’re getting 25 volts across that phase. All right, this is the phase voltage. If I was to connect it to line, so instead of going from one side of the load to the other side, if I go from line to line, my line to line voltage is 43.7. So I can see that there is line voltage coming in, but in the Star formation across the load I have 25 volts, but across the line I have 43 volts.

Now let’s turn this to Delta and see the difference. So from U, we go to V. From V, we go to W, and from W we go to U. So now we have connected these lamps in a Delta formation. For Delta, we don’t need neutral, especially because this is a balanced load. All lamps are exactly the same. So let’s turn it on and see the difference. It’s visually, it’s huge difference there. The Star connection was dim lights and with the Delta connection we’ve got very bright lights. Let’s see the difference in the voltage reading as well. So if I go across the lamp like I did in the previous example, instead of 25, I’m getting 42 volts. And if I go between the lines like I did for the previous one, I still get 42 volts. So that’s the difference between Star and Delta. Measurement-wise, I can see that one it was 25 and then 43 in this one, both of them are 42. But I can see a huge difference visually with the lamps that with Star it was a dimmer and with Delta it’s a lot brighter.

TESTIMONIAL FROM MICHAEL CULLEN, 
FORMER HEAD OF DEPARTMENT, ELECTROTECHNOLOGY & ENGINEERING, HOLMESGLEN INSTITUTE
And at the time, we acknowledged that we needed a more practical-based delivery and we needed to move away from the heavy reliance on the knowledge component that a lot of time we seem to in the electrotechnology sector. And this has really brought this forward and it’s actually meant that the apprentices seem to be a lot happier after each session. And I suppose they’re actually building their underpinning knowledge and it seems to be that it’s then carrying on through so far into the next units that they go on to, such as magnetism.

Hus:
We offer ongoing phone and email support so you will always feel supported. Our aim at Infinispark is to work with you to maintain compliance, increase learner engagement, and give the trainers back some time. Please get in touch with us to see how we can work together. Thanks for watching.