Hi Robert,
thank you very much for your many useful hints! The availability of the CT’s mentioned under Use in North America — OpenEnergyMonitor 0.0.1 documentation is unfortunately somewhat limited here. But I asked YHDC for the transformer winding ratios and the burden resistor values (because I couldn’t find that information in the data sheet) and received the following information:
SCT013 has ratio 1000 ,2000 and 3000.
The conventional output voltage model has 1800 turns.
SCT013-015 resistance is 180 Ω and 390 Ω
SCT013-030 62Ω
So you’re right, the SCT013-030 actually only has a few turns less and a relatively high resistance. Is my assumption correct that I would hardly achieve any improvement over the SCT013-000?