Husnen Rupani:
Let me show you how the students will measure voltages and currents at different points on this board.

We’ll start off with our multimeter setting up to DC volts, and we’ll start from the output of the solar panel. So as you can see, we have various test points here. We PV array output and then we have the output from the isolator, and then we have some test points here. Then we have test point here, and finally we have one over here. So that’s where we’re going to measure voltages. We’ll start off with DC. We’ll start off with the PV array output. So here we go.

So here we’re seeing about 27.62. This is before the isolator. And then if we go after the isolator, since the isolator is on, we should see about the same voltage. So from the solar panel to the isolator, we have 27.62. After the isolator, since it’s on, we still have 27.62. That is then going to the PV input of the solar charge controller, so let’s measure the voltage there. And we’re seeing about 27.5. So we have a little bit of voltage drop somewhere.

Let’s see how much voltage our charge controller is providing. So if I go to the battery side, we’re getting about 14 volts. So the solar panel is giving 27.5 volts to the charge controller, and the charge controller is giving 14 volts to our system.

Let’s see how the rest of the voltages work. Battery terminals here. Let’s see if we can measure the voltage of the battery. So our battery is showing 13.69. Let’s see the voltage that is going to the inverter. So this is where the battery connects to the inverter, and we’re going to connect our multimeter there. And I’m getting about 13.39 volts.

Now, after the inverter we have one more test point, but that’s AC. So let’s change our setting to AC and let’s see what voltage we get here. So we’re getting about 23.5.

So as I mentioned, during the startup phase, the output of the inverter is 230 volts, but we have a transformer at the back that converts it or drops the voltage down to 23, which is what we’ve measured here. And that is the voltage that is going to this installation. That lamp is a 24 volt lamp, so this whole installation is working on ELV.

Let’s measure the voltage on the power circuit. So let’s turn the power circuit on and connect our multimeter. Still in AC setting. Turn that on. And we’re getting 23.45 volts.

Now that we’ve measured all the voltages, let’s look at the current flow. We’ll measure the currents with my clamp meter. I’ll set this up to 60 amps DC, and we’ll start from the input of the solar charge controller, which is the current that the solar panels or the simulator solar panels are supplying to our system.

So I’ll hook it up here, and I can see that the solar panels are providing 4.15 amps. Now the solar charge controller is converting that 27.5 into 14, which is then charging the battery, sending it to the inverter, and so on.

So let’s see how much current our solar charge controller is providing to our system.

So here we’re seeing 8.2 amps. So the solar charge controller is taking 27.5 volts at 4 amps or 4.15 amps and giving us 14 volts and 8.18, 8.2 amps. Let’s see how much of that is going to the battery.

So if I connect that here, I’m seeing 4.92. Now, the way I can tell that if this current is going to the battery or not is because my solar charge controller is in bulk mode, which means it’s sending out, the current is charging the battery at this stage. So 4.92 is going in here. Total of 8.2 was coming out, out of that 4.92 is going here. Let’s see where the rest of the current is going.

So we know that the inverter is also drawing some current. Let’s look at the current that is going into the inverter. And we’re seeing 3.16 amps here. So 8.2 coming out of there, about 4.9 going to the battery and about 3.16 which is going there, which roughly adds up to whatever our solar charge controller is supplying.

And that’s how the students will measure the voltages and the currents. Thanks for watching.