SCT013-000 compared with other SCT013-XXX - explained


#1

Hi, thanks for a great product and the ongoing updates.

I am new to IotaWatt and purchased a range of SCT013 clamps, thinking that the 1% accuracy would be better achieved if the amp rating of the CT clamp better managed each of my monitored circuits. I have been getting some strange reading so went back to check specifications etc. In doing so I have discovered that the spec sheet for the various SCT013 clamps show the electrical design of the models with part numbers other than 000 as being different to the 000 model. The spec sheets for these models eg SCT013-30 does not include a turns-ratio where as the SCT013-000 does. The spec sheets can be found here

http://en.yhdc.com/product1311.html?productId=401

I am assuming that therefore I cant select type as SCT013-000 and need to select generic, however if I do this I am unable to calibrate the CT clamp as I cant find out the turns ratio etc.

I guess I made an assumption that SCT013-000 was a family of compatible clamps but as this is not the case am I able to use the other variants ?

Thanks,Dean


Sorting out an Australian three-phase installation
#2

That’s not the case. While that approach apparently increases the accuracy of some other energy monitors, I have not found any advantage to doing that with IoTaWatt. It has more accurate components and calibration and many times greater sample rates.

I’m well aware of those variants of the SCT013. The 030 and 050 models are included in the IoTaWatt configuration tables, but they are “Voltage” type CTs - which means that they have internal burden resistors. So to use them, you have to remove the burden resistors in the IoTaWatt. Not a process I would recommend unless you have electronic technician skills.

If you do remove the IoTaWatt burden resistors, you would need to specify burdens of “0” for those input channels using configure burden menu. After that, the input configuration menu for those channels will show the 030 and 050 voltage type CTs as a dropdown choice, and you can select and use them.

The basic voltage type SCT013 is a slightly different animal from the SCT013-000. It has fewer turns at 1860 vs 2000.

My recommendation would be to get some SCT013-000. They are cheap enough. If you are in the USA, I can supply Echun CTs. I have 200A, 100A, and 50A models…


#3

Thank-you. I am in AU so I will source the SCT013-000.