Daft CT Question

I’ve been using emon for some time now, currently I’m trying to track and monitor more and more circuits around the house.

In my basement, I have two MCB’s supplying two power circuits in a plant room. I want to measure the consumption for the plant room, I’m not bothered about the discreet measurements for the two circuits.

I have an emonTX in place nearby, I have only 1 CT input spare for this purpose… If I put the CT clamp around the wires from both MCB circuit’s will it measure the combined current, or is this flawed / dangerous in any way?


Yes (provided both wires are the Line or both are the neutral and both go through in the same direction - otherwise currents will subtract). No, unless the total current exceeds the c.t. rating.

The only danger is to the c.t. core, if it’s a tight fit on the cables. In this case, if there is any pressure on the core, it’s liable to fracture and then it’s damaged beyond repair.

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Thanks Robert!