11 hours ago, Dex said:

Just switched the output of the inverter off, so NO load connected (which they probably doesn't like), the current being measured on the input is now 3.12A

Hello Dex. Just a quick question , if you say you have disconnected all the loads from the inverter where do you measure the 3.12a? On the battery side?

I installed a couple of panel kWh meters in the various dbs on my system to use as a "control" , I am not necessarily looking at the values it self but rather if the all stay consistent with each other. The interesting thing is that the inverter watts that is recorded by the Axpert seems to be quite accurate , or should I say the kWh recorded by Emon using the w reading. If I measure the grid watts from the inverter  and compare it to that units consumed on the prepaid meter they are within 0.2 tenths of a unit of each other. So I would say check your inverter watts over some time and compare that with your utility account and check how close they are. 

If you have solar panels I would not recommend charging the batteries with the grid as you can do the for free with the panels and you loose about 25% of energy when charging through the grid. Something else to consider is that if you have two inverters running , in theory , you will have double the load on the batteries as well. So if your inverters runs on 60 - 70 w then you will also have a total load of 140w when you are running in grid mode. 

 

yes you are correct, 50W no load, just checked.

I've got a pre-paid meter display right next the inverters so I am going to monitor the kwh units on the display versus the power the efergy system shows under 3 conditions :

1. inverters bypassed

2. inverters connected but no battery charging via utility power

3. inverters with battery charging.

I guess this will be the ultimate test. 

 

Hi Paul, 

So I measured the current on the L phase going into the inverter (both). According to the manual, no load in 50W so times 2 means I should see a current draw about 0.4A (100W).

I have a laptop connected the devices collecting all the data just not kwh meters on the other lines.

I'll try the pre-paid kwh unit check as above and how it differs based on the operation and see how this looks.

Thanks for the input.

 

19 minutes ago, Dex said:

pre-paid meter display right

Might not be useful to you directly (perhaps someone googles into this later), but if you have a Conlog meter, you can press #1# to get a power consumption readout. It's averaged over 15 seconds, but it helps :-)

21 minutes ago, Dex said:

So I measured the current on the L phase going into the inverter (both)

Hi Dex , if you measured the live input into the inverter I am almost 100% sure that you are charging the batteries. Since you don't have any load going out of the inverter. The Axpert uses the batteries for self consumption and not the grid.  Do you have a BMV connected to your batteries so that you can see the charge / discharge of the batteries outside of the Axpert?

Hi Plonkster, I do have a Conlog meter, didn't know it was possible to do that, thanks!

Hi Paul, I changed one of the settings, 16 - which determines what charges the batteries, to OSO, so now its only supposed to charge via the solar system. When I initially changed this setting I did see a drop, so it was part of the problem for sure. I don't have a BMV, looks like its worth the investment though.

 

44 minutes ago, Dex said:

Hi Plonkster, I do have a Conlog meter, didn't know it was possible to do that, thanks!

The BMV will make quite a difference in how you manage your batteries, but since you can get the value from the prepaid meter and that is your ultimate reference (since this is where the money goes )  use that and see how close the values are. 
I can remember but do you log your data from the Axpert?

Hi Paul, yes, I have a laptop connected via USB to the one Axpert and log all the data (both units show up via this connection) 

Then I would say look your Grid consumption every day and compare it to your Logs from the Axpert. It was said before but I won't put any value to the efergy meter , apart from giving you an idea as to if the loads are high or low. 

Data is your best friend!

quick bit of feedback.

the efergy meter is the culprit, its over reading. If I use the internal power function of the Conlog meter (thanks to Plonkster for this!!) and compare to the efergy meter, the efergy reading is way out, in fact by the factor I thought I lost across the inverter. So over the last couple of days I have checked the metered kwh unit value (what I am paying) versus the efergy value and overnight it over reads by double. I must say I didn't think they were that bad! So in reality the Axpert IS working as it should.

I think what also got me going on this wild goose chase was the fact that the Fluke Clamp meter also indicated current lost from input to output of the inverter. 

I would like to monitor the power continuously, what is most cost effective system to logging and recording the information?

thanks again for the help.

57 minutes ago, Dex said:

overnight it over reads by double

Same at my place. My LED downlights have an atrocious power factor (around 0.2), so my combined lighting load (there are some other better-behaved lights too) is maybe 350W, but the apparent power is 700, which is what an Efergy would have shown.

59 minutes ago, Dex said:

I would like to monitor the power continuously, what is most cost effective system to logging and recording the information?

Something like the Eastron SDM-230 is affordable (compared to the Carlo Gavazzi at least!) and works well, though it needs a bit of software and a rs485->usb cable to read it.

Disclaimer: I don't vouch for the seller above. His ratings look good but on the shipping page you can clearly see he is a drop-shipper. I prefer not to buy from drop-shippers, I'd rather go directly to ebay before I do that.

Or this one, they are around €75, a bit costly perhaps, but properly good quality. Not sure where you'd find one locally and shipping from abroad will likely kill the deal.