Submitted by Curtis (not verified) on Wed, 03/03/2010 - 15:43.
I have looked at the CR Magenetics CTs...they look really nice. The one thing that turned me off about using a CT without integrated burdon resistor is the safety factor. I understand that without the burdon resistor on it, there can be safety issues with opening it up while not connected to anything, or putting it on the wire not connected to anything. I have ordered a couple of the seeedstudio 30A CTs to use for testing and have a board design 80% done.
Yes, you would need one of the MCP3906A chips for each circuit. The thing that intrigues me about that is it has a 16bit ADC integrated and can give you 1W resolution. It is designed for power metering and conforms to the international standards, so accuracy is probably a lot better. My hopes is that I can build the monitoring for each circuit for less than $25. Since I have about 40 circuits, that comes out to about $500 for the whole solution.
We'll see how it works out. As I make progress, I will try to blog about it.
I have looked at the CR
I have looked at the CR Magenetics CTs...they look really nice. The one thing that turned me off about using a CT without integrated burdon resistor is the safety factor. I understand that without the burdon resistor on it, there can be safety issues with opening it up while not connected to anything, or putting it on the wire not connected to anything. I have ordered a couple of the seeedstudio 30A CTs to use for testing and have a board design 80% done.
Yes, you would need one of the MCP3906A chips for each circuit. The thing that intrigues me about that is it has a 16bit ADC integrated and can give you 1W resolution. It is designed for power metering and conforms to the international standards, so accuracy is probably a lot better. My hopes is that I can build the monitoring for each circuit for less than $25. Since I have about 40 circuits, that comes out to about $500 for the whole solution.
We'll see how it works out. As I make progress, I will try to blog about it.
Curtis