as far as i understand the new victron Energy Meter - Parameters could be set
wrong / slightly incorrect measurements are more a problem of resolution, not noise
A CT designed for 100A will be more accurate if it measures 3A instead of 1A - but maximum is then 33A itnstead of 100A
Apologies it was a kak attempt at an explanation. Got lost in a tangent thought.
Besides the ratio/error percentages for accuracy aka use a good CT if you want good readings…
Problem 1 — The sensor
Trying to measure a tiny current with a big CT.
A smaller-rated CT helps this. But doesn’t allow the big reading range.
More windings don’t help as then your max amps are limited. And your cable size.
Problem 2 — The computational side
Trying to calculate a tiny amount of real power while lots of other AC stuff is happening. The distortion effect of non linear loads, the zero crossing problem.
Its difficult to write a one size fits all fix, when the $200 meter isn’t a power analysis device and doesn’t know what it is compensating for. Any correction the meter applies has to be a general-purpose algorithm across every installation — it can’t know your specific noise fingerprint.
Chasing a 50watt accuracy has diminishing returns. For the 50watts it’s probably easier to conditionally disconnect. Then it’s definitely at 0w.
I have a cheap Shelly 3EM for my Victron ESS System - Consumption from net in complete July was 23,4 kWh
For a friend i installed a Victron ESS that just reads out the house Meter by SML/ Tasmota - consumption from the net in complete July was 12,4 kWh
I don´t think it makes sense to invest in more accurate sensors?