Hi to all! Pulled the trigger a few weeks ago and ordered up an emonTx+WiFi for delivery to South Africa to commence my power monitoring journey. With delivery inching closer I’ve started diving into things a bit deeper, and find my mind swirling a bit with the information available… Eventual aim is to determine general power use patterns, and to aid in deciding on a suitable battery backup system for our recurring cyclical power cuts (hopefully eventually leading to a PV or wind charging system). (We do not (yet) locally have domestic power being fed into the grid, although the climate around this is changing.)
Domestic power supply in S. Afr. is ~230 Vac @ 50 Hz.
Main incoming circuit breaker (CB) to my house is rated 63 A. I also have:
- 32 A CB - stove
- 20 A CB - electric geyser
- 20 A CB for each of three plug circuits
- 10 A CB for each of two light circuits
To save on shipping charges I’m sourcing current transformers locally. I believe I have a similar/identical YHDC SCT-013 (100 A : 50 mA). This will be fitted to the main CB for total power measurement.
Although my thinking was to get a SCT013-050 ( 50 A : 1 V) for the stove circuit and and further two SCT013-020( 20 A : 1 V), one for the geyser and last to find my most power-hungry plug circuit, further reading on the forum has me confused.
I am new to working with Raspberry Pi based systems (this project is part of my learning).
I have basic soldering skills, and basic understanding of electrical power theory.
I do not know Arduino, nor am I (yet!) familiar with modifying and updating sketches (e.g. modifying calibration values).
Question 1:
I believe the YHDC SCT-013 I can source locally is identical to the one offered in the OEM shop. With a 50 mA output, is there a preferred port/input to plug this into (#1 I’d assume?)
Question 2:
For my described use case, would I be just as well getting three SCT-013 for mains, stove and geyser, and only one smaller CT for the higher-precision input 4?
Question 3:
With my remaining CTs being 1V output (compared to the 50 mA of the “main” CT) - do any modifications need to be done to plug these into the remaining input ports? I am aware of the power limitation (19A / 4.6KW (@240V)) for port 4 - to my mind this means I should use a lower rated CT for this input?
I can provide URL to the supplier data sheets for the CT I’m looking to purchase if these can be of use.
Edit 1: Formatting and numbering correction