Submitted by charliemic on Fri, 20/12/2013 - 23:47
Hi all,
I have an emonTX sat on top of my distribution board, with the CT sensor inside the board. This is the only way I could get to a live cable as my incoming electrical supply is hidden within a wall.
I've been getting some strange readings from the emonTX, which after a quite a bit of problem solving (see: http://openenergymonitor.org/emon/node/3004), I have narrowed down to a problem with the CT cable, or the CT sensor itself.
Basically, if I fiddle around with the cable, I can get the sensor to give very large readings of power from 2500W to over 4000W, even when I know I am only pulling around 300W.
The problem is I am struggling to know what exactly is causing the problem. It appears that when I pull on the cable, it causes the reading to shoot up. But not always.
I will try and have more of a play tomorrow, but I wondered if there could be an issue here to do with the CT cable itself picking up interference (induction?) from cabling and terminals within the board. The clamp is fitted very snuggling onto the live, but is close up against the neutral. The cable then loops back over the top of various cables serving different circuits.
Any thoughts?
Right now I have managed to find a position that gives reasonable figures.
I'll try and get some photos of the board in the morning to show you what I mean.
CT Sensor in a distribution board
Submitted by charliemic on Fri, 20/12/2013 - 23:47Hi all,
I have an emonTX sat on top of my distribution board, with the CT sensor inside the board. This is the only way I could get to a live cable as my incoming electrical supply is hidden within a wall.
I've been getting some strange readings from the emonTX, which after a quite a bit of problem solving (see: http://openenergymonitor.org/emon/node/3004), I have narrowed down to a problem with the CT cable, or the CT sensor itself.
Basically, if I fiddle around with the cable, I can get the sensor to give very large readings of power from 2500W to over 4000W, even when I know I am only pulling around 300W.
The problem is I am struggling to know what exactly is causing the problem. It appears that when I pull on the cable, it causes the reading to shoot up. But not always.
I will try and have more of a play tomorrow, but I wondered if there could be an issue here to do with the CT cable itself picking up interference (induction?) from cabling and terminals within the board. The clamp is fitted very snuggling onto the live, but is close up against the neutral. The cable then loops back over the top of various cables serving different circuits.
Any thoughts?
Right now I have managed to find a position that gives reasonable figures.
I'll try and get some photos of the board in the morning to show you what I mean.
Chris
[This is essentially a duplicate of EmonTX: Strange power readings ]