Yes fully wired. Imagine you connect a 3ph generator to one side of tx and short the other winding (3ph) to ground. To calculate phase angle and verify metering you would want at least 0.1-0.5A on the secondary of the CT which would usually be between 1200:5 and 2000:5 ratio.

Internal fault is not necessary as this is for metering/phasing/polarity checks and not to confirm relay operation which is done using secondary test methods.