It's your place to connect with experts and peers, get continuous support, and share knowledge.
Collaborate with multiple experts and discuss various topics about Power Meters and Power Quality. From design & implementation to troubleshooting and more, get support from experts and share your experiences by subscribing to the Schneider Electric Exchange forum today.
You can subscribe to this forum after you log in or create your free account..
Posted: 2015-08-19 06:12 AM
Summation CTs with 5A or 1A outputs work with any power meter supporting those inputs. The meter is blind to what is creating those currents.
At the customer the IEM3255 with Summation CTs shows only half of the real current.
What could be the reason?
The connections - particularly of the primaries into the summation CT may be suspect and you need to think about the proportions and size of the summing.
As I mentioned before, if it's a true 5A or 1A output, the summation of the induced current must always be less than this. Please provide the make/model - datasheet on the summation CT you are using.
this is only half of current, and only half power.
its a KUW1/30-200 CT from Janitza
This is actually Cable split core current transformer - they should probably have something like this, too:
Exactly - Bojan's example is exactly right. It adds up the primaries, the proportions of which need to be added together.
That said - are you using a mix of 1A and 5A CTs going into the Summation CT?
you are absolutely right. For 1+1 it sould be set to 400A. For 1+1+1 is should be set to 600A
Thank you very much