Hi. Was reading the book Arudino Projects to Save the World and I came across this site. The project in there regarding power usage monitoring was very interesting as it was an idea I never thought of using my Arduinos for.
So now I am in the acquire parts stage and was wondering what SCT current transformer I need.
I live in the US and my house has a 200 amp service, standard in this area for houses with electric heat. I took off the service entrance cover and see two large wires coming from the pole. My question is will the SCT-013 fit over the wires or do I need to the SCT-019? I don't have alot of room inside where the wires are coming in but I know I need 2, one for each leg of the 220 volts. Also, it seems I would get better resolution using the SCT-013 than the SCT-019. I don't think I am using anywhere near 200 amps (except maybe in the middle of winter when all the heat is one). Lastly,any good US sources for the CTs? Thanks.
JC
Re: SCT-013 vs SCT-019
The YHDC website and the relevant data sheets will give you the physical sizes of the c.t's, and you can measure the overall diameter of your infeed cable. I can only speak of the 100 A version - you'll find performance details in the test report in Building Blocks. The 100 A c.t. with an emonTx gives reasonable accuracy down to ½ A or so, then the accuracy deteriorates, because of course it has only a 10-bit ADC.
I don't have details of US suppliers.
You might like to trawl the forums for comments from fellow US users.
Re: SCT-013 vs SCT-019
If you follow the link at the top of my original Mk2 Router thread, you'll find details of my preferred CT. The hole size is substantially larger than for the standard YHDC version. This allows me to wrap extra turns of wire around the CT in order to simulate surplus power when the PV itself is not active.
The Magnelab CT is much less sensitive than the YHDC one so needs a larger burden resistor. For the purpose of calculating "real power", phaseCal seems to have very little effect so you can safely ignore the warnings that I posted a while ago. For a 3kW maximum, a 150R burden with the YHDC CT works fine, and I use a 680R burden with the Magnelab one.
Re: SCT-013 vs SCT-019
Dear Joe,
The data sheet of SCT-013 and SCT-019 is attached. Hope they are helpful for you, Please check.
We are manufacture of SCT-013 split current transformer.
Original company is Beijing Yaohuadechang Electronic Co., Ltd. We have build new factory in Qinhuangdao. Would like to communicate more with so many friends
Best regards
Macy Meng
My Email: yhdcmacy@gmail.com