Hmmm. Weird output from EmonTX after years of perfect operation...

I've noticed an anomaly with the data from my EmonTX, I appear to using negative energy in the house...

Valid data TX >&node=10&csv=-3174,3138,0,25101<
Valid data TX >&node=10&csv=-3182,3147,0,25097<
Valid data TX >&node=10&csv=-3158,3134,0,25084<
Valid data TX >&node=10&csv=-3170,3134,0,25091<
Valid data TX >&node=10&csv=-3164,3124,0,25105<

The EmonTX is using the standard firmware from a couple of years ago, carefully calibrated at the time. Looking at the first line, I'm exporting 3174W, but the PV is only generating 3138W. I know that the house baseload is around 100-150W. 

I've only noticed this behaviour over the last few days, the system has been operating for nearly three years. I checked over all the connections last night and everything seemed fine.

Does anyone have any ideas?

 

Robert Wall's picture

Re: Hmmm. Weird output from EmonTX after years of perfect operation...

I'd suggest you check all the calibrations again. It's not unknown for component values to drift over time. Another place to look is your CTs - are the two halves still clamped together firmly, and there's not the slightest air gap between the two halves of the core? (Or less likely, was there an air gap that's now gone?)

I think we can assume the voltage department is not to blame, as that would affect both powers in equal proportion.

 

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