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Hello i am going to setup current sensor like this (datasheet) in my home, and would like to know where is it proper to put these sensors in the circuit.

Consider the two setup below:

enter image description hererent sensor

So here are my questions. Consder label X,Y,1,2,3,1B,2B,3B as AC current transducer. and the resistor are just placeholders for AC load e.g. lights, aircons,small pumps,computers,tv's, and other home appliances.

  • In setup A, Is it okay to put the sensor either in the live or neutral part of the circuit? So sensor X and Y should read the same value. The same goes for 1 and 1B,2 and 2B, 3 and 3B
  • Now setup A would waste a lot of wires if the three devices are close to each other but the distance back to neutral is far. So in setup B i joined the neutral while they were still close to each other and run only 1 wire back to Neutral line. thus saving some wire. Is this setup still okay? X and Y would still read equal, and 1,2,3 should read the current of the individual loads.

If you can provide a much more efficient setup i am all eyes.

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  • \$\begingroup\$ What about the written 10 kOhm resistances? Your transducers are not intended for mA range currents. What a the loads actually? If the loads are reactive, the sum of the currents shown by 1B, 2B and 3B can be much more than what Y shows. X and Y should show the same (by Kirchoff) \$\endgroup\$
    – user287001
    Oct 12 '19 at 18:06
  • \$\begingroup\$ please ignore the resistance value, those models are just placeholder for everyday household appliances/ electroncs. I have been told that theses sensors are very accurate so long you have the analog capability to read the very small voltage. Also these sensors have models that are rated for smaller loads. \$\endgroup\$
    – Jake quin
    Oct 12 '19 at 18:30
  • \$\begingroup\$ As the type of load, i cannot determine since i plan on putting it on an outlets so the load may vary. It could be computers,small pumps,lights,aircons, etc. \$\endgroup\$
    – Jake quin
    Oct 12 '19 at 18:32
  • \$\begingroup\$ I would like to read the power being consumed by appliances, it doesnt have to be 100% accurate but just close enough, maybe 5%-10% difference is acceptable \$\endgroup\$
    – Jake quin
    Oct 12 '19 at 18:36
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schematic

simulate this circuit – Schematic created using CircuitLab

The normal industrial approach to this would be to monitor the incoming supply (AM1) and (what you think are) your major loads. The remainder can be calculated as AM1 - AM2 - AM3. You can then decide to add additional monitoring or move the monitoring from one circuit to another.

Monitoring both live and neutral is pointless.

I suspect that what you are planning will be largely a waste of time and money as much of the consumption will be fixed. For a while I monitored my house's energy meter using a photosensor looking at the spinning disk and logged the pulse count every minute. After a few days, I was able to identify the kettle, water heater, washing machine, oven (hurry home from work!) just from the chart. All that with one data point. It was actually a little creepy how much I could infer about activities at home from the information collected.

To answer your questions:

In setup A, Is it okay to put the sensor either in the live or neutral part of the circuit?

Yes.

So sensor X and Y should read the same value. The same goes for 1 and 1B,2 and 2B, 3 and 3B.

Yes. So why measure twice?

Now setup A would waste a lot of wires if the three devices are close to each other but the distance back to neutral is far. So in setup B i joined the neutral while they were still close to each other and run only 1 wire back to Neutral line.

That means rewiring the mains circuits in your house. Probably not a good idea.

Is this setup still okay?

The common neutral would have to be sized to carry the sum of all the circuit currents.

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  • \$\begingroup\$ I only placed 1B,2B,3B,Y for illustrative purposes of the question. "as much of the consumption will be fixed." After giving this statement some thought its actually doable since load in a house are fix you can just theoretically compute the combination of appliance that would total the current. I will still pursue this approach though because the sensor would give not only current data but i can trace the location. Thank you again for your response \$\endgroup\$
    – Jake quin
    Oct 12 '19 at 20:01

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