Getting solar fitted early next week and already have a powervault battery (ac coupled) that I moved from my old home.
I though it would be more accurate to use 20amp ct (SCT006-B6) and the the high sensitivity input of the emontx to read the input and output from the powervault battery to give a rough idea of round trip efficiency and state of charge battery, it has a max output of both charge and discharge of 2700w, after reading a bit this may not be the case.
So in short which is the most accurate option:
20amp senor in the high sensitivity input (if yes do I need to scale the input)
20amp sensor in a normal port (if yes do I need to scale the input)
100amp sensor in a normal port
100amp sensor in a high sensitivity port (if yes do I need to scale the input)
Have you read the test report for the SCT-006 in the ‘Learn’ section here? If not, I recommend that you do, particularly the “Conclusions” at the end.
And yes, if you do use it, you will of course need to scale the input. The burden on the standard
input is 22 Ω, the c.t. ratio is 20 A : 25 mA. The calibration factor is the current that would give you 1.00 V across the burden, which is 45.45 mA secondary current ≡ 36.36 A primary current. So that is your calibration factor.
Thanks Robert I did start to read that but go a bit lost before I got to the bit that could of helped.
So my best bet if to use the normal port, with the 20amp sensor and scale the input to 0.4, this gives an improvement not quite the 5x that you would expect from the amp ratings as the 20amp CT can not fully utilise the resolution of the analogue input.