Need help modifying ac ammeter (shunt)

[Kneegrow2]

The reason that information is so helpful is that when I would unplug the CT from the board while Power was flowing through the primary an audible and disturbing Buzz would occur

 

[duke37]

Voltage transformers are happy with no load, they burn out with excessive current when they are short circuited.

Current transformers are happy with an output short, they may fail with an open circuit load. The buzzing is due to the core going into saturation. The windings may have failed due to excessive voltage.