Hi. I promised I'd do a follow-up video showing an unusual issue I had with my new solar power system. I had uh installed the Nph system and also to do with my old Solar Analytics system as well. Because I've got essentially two separate systems installed, I've got my original three kilowatt Uh solar array installed hooked up to my existing Sunnyboy Sma string inverter which is uh, monitored by a Solar analytics system and I've done videos on all these things I'll have to link them in if you haven't seen them.

so that's a complete monitoring solution. We just moved that three kilowatt system from one side of the roof to the other, so then we can have room for the more optimized new five kilowatt end phase system which has the 14 end phase micro inverters going into the end phase uh Envoy monitoring system which we have here. So these two systems are totally independent and they're running side by side. So I've got two different generation sources, two different Uh inverter systems, and two different measurement systems.

So yep, I've got two different systems here and I can access the analysis, data analysis, and graph uh pages for both them. So the Solar Analytics: This is my old three kilowatt system thing. This is back on now the 29th of March, so basically installed at the start of the month. First of March.

So this was just before I started. You can see the yellow is the production curve. I.e you know energy coming from the power coming from the panels. It's not energy until it's over time power coming from the panels.

and so at each moment in time, that's the peak power there. So 2.3 kilowatts produced, etc. etc. And the purple one.

Here is how much I'm actually, uh, consuming during the day, you can see during the night, I've got our two fridges. We're running two fridges, so that's apart from any like Phantom Power devices. You know, standby power. That's pretty much all we're running, so only like, you know, 150 200 watts or whatever during, uh, the night for the two fridges.

and then we, you know, nobody's home during the day. Then we come home, we use some appliances and we switch them on and all that sort of stuff. Everything's hunky-dory We've got energy produced and energy consumed. And then something interesting happened after we did the installation.

That's the day we installed it, so don't worry about that. and then the next day. This is what I started getting on the exact same solar analytics system. All we did was move the panels from one side of the roof to the other side of the roof.

What's going on here? You'll notice that the purple graph now goes negative negative. Four kilowatts consumed. How do you get a negative consumption? That's a bit weird. and then you know at like 6 p.m it goes positive again.

And what's going on here? Well, it turns out that this is actually a very common issue when you have two systems installed independently, side by side. like this and they're not. Well, I'm not going to say not install correctly, but they're not set up correctly and they don't know that each other exists and a lot of people who don't monitor their data just ignore like you would just never notice this sort of stuff or you care about it is is your net metering. That's all they care about is how much electricity they pay.

But you know nerds like me who follow the data. It's like what it's gone negative. So it turns out this is actually a relatively common problem when you have two different systems installed like this. Doesn't happen if you just have one system installed, and there's actually a fairly simple and clever solution to fix this.

So let's go through it. Just a quick check though of the end phase one. This problem not only happened on my old three kilowatt system here, it also happened on my end phase one. This is where like it was installed here, but I don't know.

They didn't switch the data monitoring on until there and look 200 watts consumed and then during the day the this one's the yellow one is the uh, actual consumption. In this particular case, it's going negative minus 880 watts consumed and then mysteriously. um, at night the consumption goes positive. What the Now When I posted this on Twitter, quite a few people said oh, your current clamps must be installed backwards and that you know, seems a legit uh thing because well, after the installation, we're now getting negative current consumption right on on both of these uh systems.

Here it turns out, no, the current clamps weren't on backwards, so if you aren't aware, it's uh, current clamps like these ones that they install on these monitoring systems to allow you to measure the current not only from your solar panel. So you can measure the production power coming from your panels, but you can also measure the consumption of your house. And you can measure the current going out to the grid as well. And you can see maybe you can see just on the top of there there's a little arrow and you have to install these the right way.

And sure enough, if you install it back to front and the current goes in the other direction, then well, it's going to give you a negative output. And yeah, that's a real thing, you've got to install them the right way. But that's not what's going on here though. So anyway, let's go back to this graph here.

Now you might notice the shape of the production curve. I.e the sun right? So the sun is producing this yellow curve. It just so look. It dips here.

and then the purple is the consumption. The purple also dips. When the sun dips, it's look. It's almost like they're a mirror image of each other.

Hmm, what's going on? So it turns out this kind of mirror image thing is not a coincidence. There's a reason that the consumption matches what the sun is doing and why. When the sun goes down like you know, it's all gone like five or six pm, our consumption suddenly goes positive again. Can you pick it yet? Stop this video and try and figure out what could possibly be wrong with two systems on your roof and two different measuring systems giving the same negative power during the day.

And once again, if you zoom into this, you'll find that the envelopes once again, they match here. So the orange one consumed goes up when it. uh, when the value drops and look. And even during the day? look, it actually went positive like this during the day when that was up.

So see if you can figure it out before I give you the answer. Because it's it's rather a subtle thing and you've got to put your thinking cap on to figure out what's going on here. So the best way to explain what the problem is here and how it's solved is to go over to the whiteboard. So let's take a look at the potential problem you have when you have two separate solar generating units like this and two separate monitoring solutions like this connected to the one house.

Now we've got our grid up here. Here it is, and we've got our line coming in now. of course, the power can either be coming in from the grid like this, or it can be going out depending on whether or not you're using consuming all of the power from the panels. If you're producing more power in your combined solar arrays than you're using inside your house, you're going to be exporting out to the grid.

But if you're consuming more in your house down here, then your poor panels can provide, or it's nighttime or whatever, then you're going to be pulling power from the grids so current can both flow in from the grid and out to the grid like this. Now, in this particular case, we're going to look at my exact example. We've got the five kilowatt Uh system, the new one with the end phase micro inverters, and then we've got the existing three kilowatt system with the Solar Analytics monitoring system. Doesn't matter that uses a Sunny Boy string inverter.

We're just looking at. The Solar Analytics is the monitoring system that we're using, and the end phase Envoy is the monitoring system we're using for this. The inverters don't matter. So both of these systems, indeed, any solar monitoring system is going to be measuring the uh production.

what's called the production I.e the power. The current flowing out of the panels like this. so they'll have that little current clamp transformer around physically the one wire coming from the end phase inverters. And remember, this is after the inverter.

So this is after it's generated. The 240 volts are required and put it onto the main. So as I said, doesn't matter whether it's a micro inverters up here or a string inverter, this has nothing to do with the it's not actually measuring the Dc, it's after the inverter. So measuring the production from the panels is easy and simple.

You can't goof it up, you just put a current clamp on there and it goes into the input to the either the end phase envoy monitor or the Solar Analytics monitor. So each system has its own current clamp measuring that and as we saw, that wasn't the problem. Although as I said, you can actually put the transformer on back to front if you goof it up and will. You'll get negative.

But that's not what's going on here. What's going on here is we have a problem measuring the consumption. the load. Why is it going negative And why does that pattern follow the production from the panels? I.e why does it follow the sun? It's negative during the day and it's positive during the night.

What's going on? Well, this is where it gets a little bit tricky. Now, of course, the obvious solution is to simply have a current clamp on here that measures the load like that. And of course you'd have a second one here and that would go up into there like that. So each system knows about the load and consumption and once again, you can't really goof that up unless you put the current clamp on backwards, but then it'll always read backwards.

It wouldn't go negative during the day and then positive during other times. So what's actually going on here? Well, it has to do with the switchbox and the sort of limitations in there for being able to put these load measurement clamps right. So let's have a look at our switch box here. We'll expand that out and we've got like a 60 amp breaker here.

This is like the main one for the house. Just like go with these numbers. they're different for different uh scenarios, but then, uh, like inside the switch box. We've also got the five kilowatt solar arrays wired inside here as well.

the three kilowatt solar array so it's pumping that in and then you've got uh, these. this wiring. Once again, it's all in parallel like this. like goes through to separate breakers for like each powerpoint circuit might be 20 amps.

for example, light circuits might be eight amps you might have like oven, stove, or hot water. Uh, you know, different uh. fuses. Uh, like this for different parts of your circuits.

But the problem is, all of this stuff in here is like all higgledy-piggledy It's all kind of like wired together into points and all. It's a real rat's nest of a thing. That's how it is in my particular fuse box. So unless you had a fuse box that had like one wire coming off here like this and then going out into all these ones like this, you would have to like break this off like this instead of separate wise, you'd have to have one wire there, which then just went to all the other breakers like this so that then you could put your current clamp into there and you could take that reading off there.

But because your power board is like it's got one thing coming in here and then it's You know, like because the power can come back in here and it's all run on the same wires and it might flow out like that, but it might flow back in. it's it's all a mess. You want to measure just your isolated load for your house down here. So the physical construction of your fuse box and the fact that you have all these different fuses for all these different circuits and it's all wired in there all together and they're effectively like, all just in parallel, then it makes it quite difficult.

Not not impossible, but difficult on lots of fuse boxes to be able to put one simple current clamp in there. And so that's why it's actually common practice to put the clamp outside of here and put it up here like this. So the current clamp for the consumption actually goes on the grid side like this. so that goes in there like that and you would have another one, a second one like this that then goes down into there like that.

So just from a physical wiring access point of view, it makes sense to do that. But now you can probably see the problem. What you've got now is a situation where each of these monitoring systems does not know about the other one. So if you've got your current clamps outside of here, the easiest way to understand it is just to put some numbers in.

Let's say that here, where measure. Our house is taking one amp. Okay, and our solar systems here are generating two amps each. right? The sun's out.

They're both generating two amps. Okay, so we're drawing one amp into the house and we want to read that as a positive number. We want to read. This solar analytics system wants to read one amp.

But what it's actually going to read is the total production from the two different systems, one of which it doesn't know about. Uh, two amps plus two amps. So there's going to be four amps pushing in This way, like this one amps going down here. What's going to happen? Well, you're going to get 3 amps flowing out like that.

So during the day because your current clamps there, you're going to actually get a a consumption reading of minus 3 amps because the current's flowing out not in like you're trying to read and then magically night falls. This drops to 0. This drops to zero and you're drawing. You're still drawing your one amp load instantly.

You're now not reading minus three amps because it's there's nothing flowing back out. You're drawing everything from the grid you're going to have flowing. that way. you're just going to have your one amp, so it's going to start reading correctly once the sun goes down.

Now, during the day, when you've got your production curve like this, of course, you've already got the clamp on your three kilowatt array here. so it knows how much this one's producing, right? So it can actually take that. the example that we had before during the day. Two amps here.

Okay, so let's add the axes here like 2 amps. Let's say, during the day, the 3 kilowatt systems generating 2 amps like this, It knows about that because it's measuring. but it doesn't know about this system up here. So the output that this clamp here is measuring is actually four amps.

It's not two amps because you've got the extra difference in here. the extra two amps caused by this array here, which it doesn't know about. So even though having the current clamp here is a perfectly fine solution, but only if this one doesn't exist, then it would know how much it's it's actually producing, and then it could subtract the consumption from that figure and give you the correct positive figure always. But it doesn't because this is pumping an extra two amps into this system inside here.

And likewise for this end phase system here. It's got no idea that this other system here is pumping out two amps here. All I can measure is its own production plus the consumption up here. So during the day it's going to show negative as well.

It's going to show that it's exporting energy when you're actually consuming it. So how do we solve this? Well, you can actually solve it simply by paralleling current transformers. Because what is a current transformer? It is simply a core like this ion core. and it has a bunch of turns on here like this.

and it's simply a transformer and your wire going through like this is one turn and you've got multiple turns here. So if you've got your one amp flowing through here like this, you might get one milliamp flowing out of your coil like this. So what you can do is actually wire a second current transformer in parallel with the first one onto your other coming from your other production line up here. So this input has two current transformers.

one to measure the production from here, another to measure the production from here. And in this case, if you've got say, one amp, uh, one amp production here and you've got two ounce production from the other panel, then you get one milliamp out of here. Let's assume it's you know, like a thousand to one uh turns ratio. then you've got two milliamps coming out of here because you've got two amps here.

So you'll get a total of three milliamps, which is the total of the production of these two systems. So bingo your both systems. The Solar Analytics and the End Phase will now know about the total production so that then you can have the load measurement, transformer, current transformer outside here like this because of the limitations of your switchbox. and then you're always going to get a positive value because it now has the correct value to subtract.

You got it clear as mud. I could probably make this easier, but you get the idea is that each system doesn't know about the production from the other one and the way to solve it is to put two current transformers in parallel on each one. Of course, if your system had like another input here for production and you were able to set it up in software and things like that, then you could do. You know you could do the same thing.

But even if your system only has the one input and it's not designed to measure multiple arrays, it doesn't matter. Just wire the current transformers in parallel so that your system knows about the total consumption. The only downside to this Uh configuration is that if you really wanted them to be separate and you wanted this, say the solar analytics to only measure the total production from here, then there's not really much you can do about it. You can't really accurately measure the production and the consumption at the same time from this isolated system.

With the current transformer up here, you would have to move the transformer down to here. You would physically have to have it down there like that. So anyway, as a lot of installations like my one, that's not really practical so that measurement load transformer has to be on the outside and it turns out that end phase do actually know about these sort of installation issues. And if you go over to the system over here we can actually look at our there's they've now added the photo on there by the way which is quite nice.

So this is now like a real photo of my roof with the actual panels installed in there. I can actually go and like look at individual data and graph of each particular one. Here's the temperature for example. like you can get the temperature like that's the temperature of each micro inverter, not the actual panel.

but it's interesting. But anyway, if we go over to devices over here okay and we take a look at our cons in phase integrated consumption meter right? which is part of the Envoy thing. Check it out. They've actually got the two configurations here and the one mine set up to is the load with solar production.

So the end phase system knows it's supposed to subtract the consumption from the production because they share the same current clamp and they're on the grid side, but you can actually change it to. If you happen to have a panel that allows you to install the current clamp on the load like this, then well the load data, which is the problem that we've been having with this thing. Whereas it was the load, the actual consumption data which was being goofed up and going negative, the production data always worked. It was the low one that was goofing up.

Then it knows that there's nothing else that has to compensate. doesn't have to compensate for the production of these two panels. But even though the end phase system has support for this, you saw how it goofed up right at the start because there's no way that the end phase system can know about the production from the other system installed. even if there was a like a field for an offset or something.

it it's a variable figure. So how does it know it doesn't? There's no way you can know you've got another solar production system panels over here actually pushing current back into the grid or into the load. All right. So let me show you what's happening on the switchboard here.

and uh, please forgive me. this is a bit difficult. You need like three hands to keep the switchboard open unfortunately and uh, like poke at things at the same time. Anyway, here's our main Uh 60 slash 80 amps.

I don't know what it actually is, but main breaker coming, main fuse coming into the property. So this is uh, the side that we want to actually put a current clamp on to measure both the incoming um and like a consumption coming in and also going back to the grid as well. So that needs a current clamp on it for both the uh Solar analytics system which you've seen before. I've done a whole video on that and there's the three uh, current clamp inputs down there and I used to have one channel for the production I.e coming from the solar panels, another for the consumption I.e coming into the house, what we're actually consuming and then another one that I did the air conditioning as well.

but I'll explain the air conditioning consumption, but I'll explain that in a minute. And of course we've got the new uh in phase Envoy box up there. and uh, so let's have a look at what's actually going on here so let's have a squeeze around the back here. and yeah, this is not the best is it? Um, but anyway, as you can see, we've got two current clamps there.

There's the solar analytics are current clamp and there's the end phase current clamp and both of those are on. There they are. they are directional so you have to actually get the direction correct on those. So both of those are measuring the current coming into and out of the property.

so it depends on which way it flows as to whether we're consuming power, or we're actually, uh, exporting power to the grid. And here's the breaker for the Uh main existing three kilowatt system. And if we go around here, you can see how it comes out there. and it's got two, once again, two current clamps.

That's uh, the the bigger one. There is the new Uh end phase one and the smaller one. Just down in there is the Solar Analytics one. So both systems now actually are able to measure the current.

They know what the current is coming from the existing three kilowatt panel. Okay, I'm trying to keep this panel open with my elbow, but anyway, you can see another clamp here. This is the Solar Analytics clamp and this Uh cable. Here it comes from the Uh, the Ac from the new panels.

Okay, so the new five Kilowatt Uh system. So this is what we had to change. This one was actually measuring the Aircon system before. but I've now sacrificed the measurement of the Aircon power that's just now included in the total power.

And I've moved that to actually on here to measure uh, the current coming from the new five kilowatt system and I've put that in parallel. You'll notice that it's got a red marker on there, and the other one down here is brown. So I've wired both of those in parallel in there on that first channel up there, and the existing one on channel two there, which actually, uh, measures the current are coming into and out of the house up here. So by putting the two current clamps in parallel on channel one, the Solar Analytics now knows the total consumption of the entire system.

So then it's able to do the basic addition and subtraction required to figure out how much uh current is like being consumed by the property. And that was it was totally unknown before. So this Solar Analytics system is now aware of both production sources here and here, and likewise up in there. I won't show you, but they're also paralleled up in there as well.

As I said, there's one here and you can see actually the arrow there. so it's actually coming out of here and it's measuring. Uh, the production coming from the three kilowatt system and it's putting that effectively in parallel with another current clamp which is actually up in the box there rather than in the switchboard. But it's doing exactly the same thing.

So both the end phase system and the Solar Analytics System now are aware of the two difference of of each other's sources. And that's not done in software. That's done by simply paralleling up the current clamps because that's how they work. They're magnetic current clamps.

They're not active electronics. You can whack them in parallel and then you just get the combined current out of both of them. So there you go. I hope that is clear as mud, and it is.

This is one of you know, the major issues with Uh having two different production systems i.e two different solar panel systems on site is that they're always going to combine like this. And really, unless we totally scrap this entire switch box may do eventually. If we install a battery system, that's the recommendation to get rid of this ancient thing. Although it's not that ancient.

this is, uh, mid 80s. This house was built in the mid 80s, so this is a typical Uh style that was in the back then. well, at least in this area anyway. Um, and it's not uncommon at all.

But anyway, um, just due to the physical wiring configuration of this, we weren't really able to put the current clamps on the like, sort of like the house side of the meter. The only place we could really put them is over here and which is the main feed coming in from the street? and well, that just screws everything up. when one system like this one doesn't know about the production from here and this one doesn't know about the production from here. So you solve that by whacking transformers in parallel.

Neat. And I didn't have to buy a new transformer, I just reused one from my aircon. So now my solar analytics can't measure the aircon separately. But no big deal.

So anyway, I hope you found that interesting because it really is an interesting scenario caused by a, you know, a physical like a space wiring configuration issue inside the switch belts. If you had a switch switchbox that, as I said, enabled this like measurement inside here, and you could easily put the current transformer there to measure all these different circuits at once, then, well, everything's hunky-dory but in my case, a lot of cases out there you can't do that. which is why software like the En phase system actually has a specific setting to tell you where you want that current transformer. Because this is a known issue in the industry and you can fix it by putting transformers in parallel, but there is that slight limitation that you can't then independently measure things and uh, it's all too hard.

So anyway, I hope you found it interesting. If you did, please give it a big thumbs up. As always, discuss down below, catch you next time you.