North America Bundle pre-purchase questions

I’m planning on purchasing the North America Bundle, but have a few pre-purchase questions, primarily regarding the rating and number of CTs that I’ll need:

  • Do the power supply and reference transformer need to be on different circuit, or can they use two plugs on same outlet (or an adapter in a single plug)?
  • My municipal supply enters the main panel via a breaker labeled 200A. The breaker appears to be an Eaton BW 200 10k model, and has two very heavy duty black wires attached at the top. Will I need one or two 200A CTs for the main power supply?
  • The circuit breaker for our solar power system has two 25A breakers, and the solar system is labeled as operating at 240V / 18A. Do I need one or two CTs for this system?
  • The circuit breakers for the dryer and range are combined in a strange way, consisting of four breakers for 30A, 50A, 50A, 30A with the 30A ganged together (outer) and the 50A ganged together (inner). Presumably the 50A is for the range and the 30A is for the dryer. Will a single 50A CT suffice if I just want to monitor the dryer circuit (we don’t have an electric range)?
  • The other circuits I’d like to monitor individually all have 20A breakers, but I see that the minimum rating available is 50A, and there are two types of 50A CT available, one labeled “AccuCT 50A x 10mm split-core” and the other “Current Transformer 50A x 10mm split-core”. What’s the difference between these, and which is recommended?

Any advice on these questions would be much appreciated.

No restrictions. Two on a single duplex outlet (or power strip) is fine.



Dryer usually need to monitor both CBs as they are usually three wire (120V for motor, 240V for heater). You can use two 50A CTs into two IoTaWatt inputs, two 50A CTs combined with a headphone splitter into one IoTaWatt input, or one 50A or 100A CT with both wires passing through it in opposite directions as described here.

The 50A CTs are fine for 20A circuits, and you can also combine multiple circuits through one 50A CT. The two 50A CTs listed are functionally identical and reflect different suppliers. Currently out of AccuCT 50A and ship[ping Echun 50A. AccuCT should also be back in stock later this week and NA bundle will change back to shipping them. Originally there was an issue with CE labeling for the EU but that has been resolved and both will have both CE and UL recognized.

Thanks for the fast and detailed response!

A clarification is needed on the question regarding the dryer circuit. I really only want to monitor the 240V component because the circuit is going to be repurposed for EV charging. Presumably this would reduce the required CT count to one?

If you use one CT on one of the conductors and “double” the voltage, you stand an even chance of getting only the 240V power or the 240V power plus double the 120V power.

I listed three options. Two require two CTs and one requires one CT. Also, two require one input and one requires two inputs.

EV chargers are typically two-wire (120V or 240V) so that should require only one CT.