In the Philippines, we use single bushing distribution transformer on rural residential areas.?

Question

Our primary 3-phase voltage is 13.8 kv, secondary voltage on the transformer is 220 volt. Is it ok or correct to connect the (bushing) primary side of the transformer on one line of the 13.8 kv and connect the bolted primary side on the ground by using ground rod only? Assuming all the required parts are used such as lightning arrester, fuse, disconnect switch, etc.

Answer 1

No, you must also connect to the system neutral.

If you were to lose the ground rod connection, you could have primary voltage on the case of the transformer.