Telling us it can't be happening is not helpful....
Please opine as to what you think is the cause.
I have not said something is not happening.
I said it is common industry practice to have CTs near 90² bends in conductors. I also said that many if not most CTs are not shielded. The predominant number of CTs are not installed in 'vertically oriented CT cabinets'.
I have simply asked you to provide any published instructions that would have warned an installer not to put this CT where it is due to possible overheating.
In my first post, I said this CT should immediately be removed from service.
I did find one set of warnings for mounting of zero sequence rectangular CT, but it relates to nusiance tripping of GF relays.
Page 13
http://www.electricalmanuals.net/files/RELAYS/I-GARD/MGFR/C-700.pdf 
