Iotawatt can work without burden resistor?


#1

Can Iotawatt can work without burden resistor? If it can then please let me know details how it can work with complete explanation and schematic diagram?


#2

The schematic is in the hardware folder on Github.

The answer is no, it cannot work without a burden resistor. Current transformers are just that, they produce a current, not a voltage. IoTaWatt ADCs read voltage.

If the question is can IoTaWatt work with a CT that has a built in burden resistor, the answer is yes. As long as the voltage produced is less than 1VRMS you can remove the internal burden and rely on the external burden in the CT.

But this is all technology that you should already understand if you are going to plug in your soldering iron. What’s the issue that compels you to go this way? If it’s just that you have some cheap SCT013-030s then I would suggest you remove the burden resistors from those CTs, leave the burden in the IoTaWatt, and configure them as generic CTs with 1860 turns and shift of about 3 degrees.


#3

Thankyou for writing Sir… actually we are trying to connect VT to iotawatt not other CT.
I can’t see how a VT can be connected without disconnecting the burden resistor on iotawatt pcb?


#4

Of course you can connect one VT to channel zero which is designed for that. Going on the assumption you want to add VTs for three-phase direct reference, you would need to remove the burden and use the external adapter shown in the hardware section of the Github repo.

If you have not yet purchased an IoTaWatt, I can offer you the new version 5 unit which has the native ability to connect two additional VTs to channels 13 and 14 in lieu of CTs.