# Error in Iotawatt energy status (watts)

I have Finnish 3-phase sysytem. I don´t know real phase of VT (I use extension power cable from different place) but it is A now. I connected three CT:s, phases A, B and C. All of them are connected to single phase solar inverters. One is 2x500Wp and the others 500Wp. So the status of the Iotawatt is too big: What I can do next?

Inputs Outputs
Input_0: 234.9 Volts

Input_1: 718 Watts, pf: 0.47
Input_2: 1558 Watts, pf: 1.00
Input_3: 1569 Watts, pf: 0.55

Firmware version: 02_04_00

Running time: 0h 49m 43s
free Heap: 25096 773 samples per AC cycle

First, is this a four wire or three wire system?

If it’s a four wire system, which I suspect it is, then it appears that Input_2 is probably correct. I don’t know what it is measuring, but it’s hard to get a PF = 1 if the phase reference is wrong. The CT does appear to be reversed, but let’s leave that for now, the IoTaWatt is correcting that.

The other two appear to be assigned to the wrong phase, based on the power-factor. If your description of the system is correct, you should be able to change the phase of Input_1 and Input_3 to another value that produces PF close to 1.

Without seeing how your system is connected, I can’t offer much more. If the power appears to be more than can be reasonably expected from the inverters, then there is something else going on.

I’m not familiar with how Finland works. Seems to me that a total of 2 kWp could be handled by one single-phase inverter. It doesn’t seem worth the expense to have three inverters. Are you sure 1500 Watts isn’t a reasonable output? If my assumptions about phase above are correct, and I don’t have high confidence due to very limited information, the outputs would be about 1500, 1500, and 3000 for inputs 1, 2, and 3 respectively. But that doesn’t seem to be consistent with your stated panel output.

Sorry, I was stupid and the default CT was wrong. I changed the setup Now it looks more realistic, only Input 1 is much lower than exepected. I must check if solar panels are dirty or something. I think, that I have three wire system, newer systems are 4 wire.

Input_0: 235.1 Volts
Input_1: 159 Watts, pf: 0.43
↺ Input_2: 370 Watts, pf: 1.00
Input_3: 424 Watts, pf: 0.57

There is no “default” CT.

It’s not clear what you are trying to accomplish with this, but installing derived three-phase requires a methodical approach. There are a literally dozens of combinations of phase assignment and CT orientation, and only one will yield correct results. There is a documented approach that you could use, or you could start by following the suggestions I posted yesterday.

Or you can clean your panels and hope that the clearly bad power factors will improve. I doubt it.

Virtually all of the three-phase systems using IoTaWatt are four-wire. The age of the system is not a reliable basis for making that determination.

## Configuring the Input Channels

" The next drop-down box is the model of the CT. Initially it will be generic, Click the drop-down list and select the ECS24200 CT." from <-- That was my problem.

And I know, that I have old Finnish system, three phases and one negative/ground or something like that. Old 3-phase power plugs have four pins. Nowdays there are five pins. https://www.finlandforum.org/viewtopic.php?t=94245

But yes, I must read documentation. It´s normal first to try new device and then read the manual.

BThat is not a default. It is a template for specifying a non standard CT. You would have had to specify a turns ratio in order to use it.

That was a problem. You have others as well.

I would respectfully suggest that when you are dealing with high voltage electricity, you deviate from your normal approach.

That post describes a four-wire system.