Toroidal CT

[dfdt]

Does it matter if the primary conductor carrying the current is not positioned at centre of the toroidal CT? will it introduce any errors due to asymmetrical flux linkage?

 

[cranky108]

I think it is impossible to get the conductor exactly in the middle. So how much error would be a concern to you?

 

[scottf]

The answer is: it depends.

As a very general statement...the higher the primary current the more important it is to have the primary conductor centered. A general rule of thumb is that at ~3000A and below it is not so important, but there are plenty of exceptions to that.

 

[dfdt]

Thanks gents for your views.In my view regardless of the position of the primary conductor, all the flux generated by the current carrying conductor must intercept secondary winding and hence the position should not matter.

 

[scottf]

bholas-

The positioning of the primary conductor and the proximity of the return conductor can most definitely be an issue with CT performance. For higher current applications, it is common for us CT manufacturers to use special secondary winding designs/shielding to mitigate the effects.