That is correct, the under 24, earned income support rule, applies only to eligibility for the refundable portion of the AOTC. So, you qualify for up to $1200 of credit (60% x $2000). So, if your tax liability is only $924, it will be wiped out.
But the tax on $30,000 taxable income, for Single filing status, is $3413, not $924.
