According to IEC60950-1, Chapter 5.2 Electric Strength, Table 5B, the test voltage is 1500VAC for a device with basic insulation and 230VAC operating voltage. Where can I find this test voltage for such a device in IEC62368-1?
IEC62368-1 has three methods for determining the electric strength test voltages. Those are explained in sub-clause 220.127.116.11. As stated, the highest value calculated from the three methods must be used. So far, based on product evaluations to date and without the benefit of empirical or supporting data, Method 1 seems to yield the highest test voltage for the scenario you are inquiring about.