Hi

I connected the WEM3080T according to the diagram in the attachment. If circuit breaker 1 is connected, the WEM3080T reads correctly currents, voltages and powers. If circuit breaker 1 is disconnected, I have consumption, voltage WEM3080T reads incorrectly according to the picture. I know I can't read the CT3 current correctly, but I tested it.


This is what the graph looks like when reading with Main Breaker 1 offline.


For Overview I can see:


What changes are needed?

Mihai C


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Hi:
First of all, Why there is inverter power output during the night? If it is a hybrid inverter and the battery is charging by grid during the night?


I guess there is some ct direction error in the installation, but I need more data.
Please give us a snapshot of the overview page(as you provided the first pic) that include the whole day's data.

The first pic only includes a little data that in the night.

Hi

Yes, the system now runs on batteries, especially at night.

The system as it is in the first picture works well when I am connected to the network, only when I go on batteries or solar this erroneous information appears. In the picture is the consumption for yesterday. There is no real consumption for the House.


From this pic , the inverter power output is negative, it is wrong. The inverter power output should be always positive .


So please change the direction of the CT that clamps on the wire of the inverter output firstly.


Then give us a snapshot of overview (whole day after  the CT direction change)



HiYes, the system now runs on batteries, especially at night.
The system as it is in the first picture works well when I am connected to the network, only when I go on batteries or solar this erroneous information appears. In the picture is the consumption for yesterday. There is no real consumption for the House.

Hi,

I changed the position of the CT that clamps on the wire of the inverter output.

According to the picture


 But the problem is that on the chart I don't have the power that the picture below shows.


column 2 has a power of -368W, it is not displayed on the chart, and on column 3 I have the power 0W although the voltage is 229.9V and the current is 1.35A. why?

Mihai

It seems not take effect, the power reading of inverter output still display negative .Have you confirmed that you change the ct direction?



you can confirm the inverter power reading by calling the local API of the energy meter
HTTP://local IP of the energymeter/monitorjson
Then you will see the power reading of the inverter .
If the inverter power reading displayed positive , it mean the ct direction is correct.

Please let the inverter power display positive value firstly.


Usually, the inverter power reading display negative many be caused by two reasons.
1 CT (which is clamped on the wire of the inverter output) direction is wrong .
2 phase mismatch.
For example ,You use phase B to monitor the inverter output and clamp the CTb on the wire of inverter output,but you connect the Ub(voltage input of phase B) to the grid voltage .
Then there will be a phase mismatch, and cause a negative power display in inverter power reading.

Hi,I changed the position of the CT that clamps on the wire of the inverter output.According to the picture But the problem is that on the chart I don't have the power that the picture below shows.column 2 has a power of -368W, it is not displayed on the chart, and on column 3 I have the power 0W although the voltage is 229.9V and the current is 1.35A. why?Mihai

1. yes, it is a hybrid inverter and the battery is charging by grid during the night.

2. the circuit breaker 1 is disconnected all time.

3. I reversed the direction for the ct from the inverter.

4. in this picture, at the same time, i have real power consumption, but in graphical chart is very small, why?




The Power for CT3 I have 2,93A, tens 229.7 and power is:  -18W???????????

A snapshot for  last day





The Power for CT3 I have 2,93A, tens 229.7 and power is:  -18W???????????


1 You do not need to use too many "?" in your question.

2 the power here is active power

active power = voltage*curreent* power factor

power factor = cos(phase angle between voltage and current)


So I guess your problem is for this reason.(I mentioned it in previous thread)

"2 phase mismatch.
For example, You use phase B to monitor the inverter output and clamp the CTb on the wire of the inverter output, but you connect the Ub(voltage input of phase B) to the grid voltage.
Then there will be a phase mismatch, and cause a negative power display in the inverter power reading".


Please check which voltage had been provided to the Uc in your energy meter.

You should make sure that the Uc is powered by the voltage of the inverter.
Otherwise, it will appear such a phenomenon like in your pic.(the power factor is very low, or the power is always negative even you change the ct direction)


Hi,

because I work a moustly off grid, I changed the schematic.


With this schematic I see on Overview:


Where Ub,Ib, Pb is OK.

But in this grafical the Pb is very small.


Why the graph is different from the measure?

Thanks

Misu


Hi:

The "load power" displayed in the overview page is not the data of meter type "load"

In fact,it is calculated by the grid power (meter type grid) and inverter power (meter type inverter)

the formula is as below

load power= inverter power + grid power(consume from grid: positive, export to energy: negative)

hi

please tell me how connect the CT1, CT2, CT3 for the schematic above,

and how the inverter power and grid power its calculated.

Until the battery runs out, use the off grid inverter

Best regards

Misu

how connect the CT1, CT2, CT3

it is depended on what you want to monitor.


There is a discussion about what can IAMMETER done in off-grid inverter monitoring.

https://imeter.club/topic/42

hiplease tell me how connect the CT1, CT2, CT3 for the schematic above, and how the inverter power and grid power its calculated.Until the battery runs out, use the off grid inverterBest regardsMisu
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