Inverter showing higher kWh than the meter...

[Energetic]

Any ideas? Inverter showing 120kwh and meter showing 103.

 

[edexlab]

Any ideas? Inverter showing 120kwh and meter showing 103.

cable losses on AC side will cause the two different readings you could move the meter next to the inverter but you can't reset the figures

 

[Energetic]

The AC run is only about 1m long and besides that it's a 20% difference, surely losses can't affect it that badly, even on a long run... I wouldn't mind if the meter was 20% higher

 

[edexlab]

The AC run is only about 1m long and besides that it's a 20% difference, surely losses can't affect it that badly, even on a long run... I wouldn't mind if the meter was 20% higher

this sounds a bit dodgy I assumed you had a fair run of cable
what inverter and size Ac cable have you used?

 

[JulianC]

I remember reading in one inverter manual (sorry, can't remember which one but possibly a Fronius?) that the generation reading on the display was approximate only and couldn't be relied upon. I thought it a bit strange - you'd think it would be very accurate.

 

[Energetic]

Originally it was in 4mm with a Zs of 0.27. I have gone back and changed it to 6mm and i'm getting a Zs of 0.22. Still feels a bit high to me. The r2 is 0.2, the R1 is 0.2 the RN is 0.2... these are end to end from DB to inverter terminals through the meter and isolator. The Ze is 0.11.

Its a 4000TL with only 1 string on atm. Second string goes on next week.

 

[Energetic]

I remember reading in one inverter manual (sorry, can't remember which one but possibly a Fronius?) that the generation reading on the display was approximate only and couldn't be relied upon. I thought it a bit strange - you'd think it would be very accurate.

i have seen that somewhere, our feeling is that the inverter is right on this one... going to swap the meter out tomorrow...

 

[edexlab]

What cable are you using, is it SY/flex, I'm wondering why your R2 is the same as r1 or r N
ie if you had used t&e you would expect the R2 to have a higher reading end to end
I'm sure you've probably done this but if you have'nt check the connections as this sounds high for 1 metre of 6mm you could test resistance through the meter itself ,and another length of cable same length as a comparison add together should be similar to your readings

I've come across this once and that was only a gradual lag of 15 kwh over 6 mths due to a long run and this was with a correctly sized cable ,in this case probably just the meter, if you find otherwise it would be useful if you post details

 

[daytona600]

depending on the inverter some are above class one accuracy
some even accurate as a power analyser
most export meters are class 2 or lower , built primarly for cost
best to fit a datalogger for accurate outputs www.suntrol-portal.com

 

[Energetic]

UPDATE: After speaking to elster and being assured meters do not go wrong i spent lots of time on the phone to SMA, changing settings on the inverter rewiring the AC side, swapping out mcb & isolator, everything but the inverter and the meter. Still getting between 10 and 20% loss from the inverters figures

Swapped the meter out today and it's fine! So we have a duff meter, our customer is now out of pocket by 180kwh which will not be compensated and we can't even get a refund for the duff meter untill it has been sent away and tested, not to mention the labour.

Do we as a business have the same rights as consumers with regard to faulty goods? Surely the wholesaler should refund us without question and try to get our customer compensation for their loss from the manufacturer?

 

[Markc]

UPDATE: After speaking to elster and being assured meters do not go wrong i spent lots of time on the phone to SMA, changing settings on the inverter rewiring the AC side, swapping out mcb & isolator, everything but the inverter and the meter. Still getting between 10 and 20% loss from the inverters figures

Swapped the meter out today and it's fine! So we have a duff meter, our customer is now out of pocket by 180kwh which will not be compensated and we can't even get a refund for the duff meter untill it has been sent away and tested, not to mention the labour.

Do we as a business have the same rights as consumers with regard to faulty goods? Surely the wholesaler should refund us without question and try to get our customer compensation for their loss from the manufacturer?

From memory and I may be wrong "we" as a company are not covered in the same way a consumer is. Sales of goods act 19....what ever it is!

I had issues with legrand a few years ago over a multi unit flat intercom system. All the hand sets that came in the kit were for single hand set systems and not multi hand set system units times 16 I had fitted! All I got for my trouble, time and effort to go and replace every hand set was a Legrand business card holder! I sort legal advice at the time and was told as we were working for profit we were a commercial client and not the consumer.

So I think you may have to suffer the cost and time. The most I see you getting would be another meter FOC.

 

[daytona600]

wholesaler should a least refund the cost of the elster meter
these are not very accurate class two but are only £20 odd
or as above retrofit very easy bluetooth or wired wwww.suntrol-portal.com fit a datalogger and client can check themselve on web iphone or pc
real time lives results for decades