Freeing up sensor ports

Support
1

My current setup with multiple 240 circuits with multiple CT sensors, one on each leg.

|1|Main_1|CT, AcuCT-H100-200|
|2|Main_2|CT, AcuCT-H100-200|
|3|AC_1_Floor_1|CT, AcuCT-H063-100|
|4|AC_1_Floor_2|CT, AcuCT-H063-100|
|5|AC_2_Floor_1|CT, AcuCT-H063-100|
|6|AC_2_Floor_2|CT, AcuCT-H063-100|
|7|RANGE_1|CT, AcuCT-H040-50|
|8|RANGE_2|CT, AcuCT-H040-50|
|9|AC_Kitchen_1|CT, AcuCT-H040-50|
|10|AC_Kitchen_2|CT, AcuCT-H040-50|
|11|Water_Heater_1|CT, AcuCT-H040-50|
|12|Water_Heater_2|CT, AcuCT-H040-50|
|13|Dryer_1|CT, AcuCT-H040-50|
|14|Dryer_2|CT, AcuCT-H040-50|

None of these inputs are currently configured to be reversed in software. I have filled up all 14 ports with sensors and I would like to monitor more circuits and was wondering if there is a way to join the two legs together so that they only take up 1 sensor port with a 3.5mm Y splitter cable? Re-setup the sensors to only use a single sensor on both legs? Or just get another IoTaWatt device?

2

You have CTs on both legs of the 240V circuits. Sometimes that’s needed and sometimes not. See the Docs here and here.

If you plot the two CTs of each load and they are exactly the same, you can remove one and check “double” in setup for the remaining one.

2 Likes
3

Most likely the AC, and WH are 240V, so definitely only need a single CT.

The other circuits probably use the neutral. My dryer runs the motor on 120V. Depending on how much you care about exactly how much energy it uses, you could choose to measure only a single leg. It would be incorrect by a certain amount.

For the other 240V circuits you could use two CTs but a single input. You have to be careful to not overload the input, but it can be done. Even with 50A CTs, the dryer is unlikely to cause an issue, since each leg will always be less than 25A. Not sure about your other circuits’ loads

4

On top of the 240v recomendations above, take a snapshot of what the HW heater and range use for a week then move those CT’s. For example, I’m not willing to shift meal time to save a few bucks so getting a baseline of X kw/week is all I needed.