New Purchaser require assistance (Canada Split phase 120V/240v)

I have a 150A panel (Quebec, Canada) split phase 120V/240V (picture below) which I would like to integrate with IoTaWatt but have some question before making the order.

  1. Main wire very short! The space with my main power line is concerning as they really made it very short! I’ll see if there is possibility to get some extra from the outside but I doubt. Which CT do you recommend? Does anyone have similar experience or suggestion?

  2. Due to space also inside the main panel, I’m looking to go with solid core 9 mm. Other than just disconnecting the wire, should I see any issue vs split core?


I think I can answer this one bob…let me know if I’m overstepping ya…
U should have np with the solid core 9mm cts, good idea with limited space…
U can use the 100amp cts for your mains if they will fit your wire size., getting some slack by removing some of that caulking to fit the cts around the wire might help…
also offered are the cts that clamp on differently which could make it easier to get around those short wires

I would agree with @Jhorner000 and I would even go the route of the clamp CTs for your two main connections. Easier to work with and rather small. I had to switch to these having a rather tight panel as well. Mine were both short and rather tight, so no play to work with. The clamp models worked like a charm. Based on the number of CTs you could do split core if you like. Looks like more space than I have in my panel, but the solid are also a good option. Just my thoughts based on the install over a year ago. Love this product!

I’ll go along with @Jhorner000 on the solid-core, although I think the split-core could fit in many circuits and you may need 100A for that big circuit.

I can’t see enough of the mains to say, but it looks like your best shot is the ECS25200 clamp toe CT. I strongly recommend that you have an electrician do any manipulation of those mains as they will be live and you don’t know what you are pulling. Those wires are not fused and you could burn your house down.

Thanks all for your input. So I went and measure the wire size:

  • 2x main wire is 16mm (150A)
  • 2x Shed Sub-Panel 9mm (50A) -> For this one I’ll used a 100A/16mm

For the main CTs, I took a few minutes to create two models in sketch up and print them to see the real size and which one fit better.

The ECS25-200 clamp is printing right now, so I’ll get back to you later.


So I print all 4 models and it provides me a good idea in terms of space.

The ESC25-200 clamp is the best in space constraints as the other ECS24-200 didn’t fit for me. Now from the picture below,will there be any issue to have the clamps so close to each other? Can it cause any kind of interference?

As for the normal circuit, both CT seems fine so I’ll go with a mixed of solid-core (ECOL09) and some split-core (ECS10-50) to move them easily if required

Based on the recommendation and the space test I did, so I think I’ll go with:
2x ECS25-200 - 200A (Clamp)
2x ECS16-100 - 100A (Split-Core)
4x ECS10-50 - 50A (Split-Core)
6x ECOL09 - 50A (Solid Core)


  • I can’t find a way in the bundle to add the ESC10-50 and ECOL09?
  • For shipping to Canada (Quebec), is it possible to split the shipping in two so I can take the advantage of the flat rate $10? Also is the flat rate USPS?



I just have to say that I like seeing how so many here on the board tackle various issues or problems. Someone who has 3D printed up a few CT samples to confirm space is just too cool. I cannot answer your shipping question, but I like the way to approach a challenge; a real engineer.

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Ditto on the resourcefulness.

I see no problem with the two CTs interfering with one another.

There is none. You can get the bundle 20% on one or the other, and the rest go at regular price.

Sure. Solve that problem and the one above by ordering the ECOL09 separately.

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Thanks @overeasy just pass the order with some extra CTs in 2 separate order. Looking forward to use it and interface it with Home Assistant.

Thanks @quella :slight_smile:

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