For a reconnect to work you need a valid network connection and the Oracle Server must be available.

I tested your scenario, and it seems to work fine. The CheckConnection function first returns ccOK when the network cable is connected, when disconnected it returns ccError, and after reconnecting it first returns ccReconnected, and subsequent calls return ccOK again.

What you might try is to debug this scenario, so that you can see exactly which Oracle Errors occur when the cable is disconnected, and subsequently when it is reconnected.