Regular CT Cons
Current transformers (CTs), sometimes also called current sensors, industry standard versions commonly have 5A as its output. They have the following disadvantages when used in branch circuits.
Regular CTs are large and will occupy a lot of space in a panel.
Branch circuit loads often do not exceed 75A, but since regular CTs have poor accuracy, they need to be wound multiple times to compensate.
During retrofitting, the existing layout and wiring constrains any new additions, since regular CTs are large, it is often difficult if not impossible to fit them.