Multiple CTs in a small space

Looking to get two IoTaWatt units for monitoring a bunch of circuits ranging from 10A-40A / 240V (Aussie install), with two 3-phase (Telsa wall charger 3x16A and AC unit 3x40A) feeds. One IoTaWatt will be in a small sub-panel, the other IoTaWatt in the main panel. No measure of mains as I get that data from PowerWall.


  • How close can the CTs physically be together? Is there cross talk possibility?
  • Looking at using exclusively the 50A solid core 9mm ones for accuracy and size, in some cases the wire would be smaller than 9mm hole, is this ok? What’s the tolerance?
  • Any other drawbacks of using all 50A 9mm solid core ones? They could be fine with 3-phase feeds as they are <50A per phase?

Hasn’t been a problem.

Smaller is fine.

Other than the obvious installation issues, the only other consideration would be that right now, I have 29 left, and will not be restocking anytime soon.

Yes, they are rated up to 50A and work fine at lower levels.

Thanks! Only listed 23 as available at order so ordered them all.

Hi Dean,
I’m having the same issue with a very busy board. I have 15 single phase switch and 3 x 3 phase switch (one is main)
I’m planing to combine single switches and get 8 x 50amp CTs.
The two 3 phase switches need 6 x 25amp CTs but the main needs at lease 3 x 63amp CTs.
Regardless of space in the switch, there is not enough input for all these CTs.
I’m wondering if you have any advise or know what are the smallest CTs available in Australia market?