Trumpy — Yes indeed, ANSI current transformers have burden ratings, but are rated in ohms, where I understand IEC uses voltamperes. With Ohm's law, though, they work out to be very similar.
An ANSI meter-class CT rating might be 0.3B0.5—that works out to a maximum primary-to-secondary ratio error of 0.3% for a ½-ohm burden or secondary “loop”.
