The shield of the TNC antenna cable is connected to the chassis of the device, and on the GNSS receiver this shield is connected to the power return potential. Since that is the case, the whole enclosure is under the same potential. We recommend users to isolate the chassis from the power return potential if it is required in their application, as we have not had any problems related to chassis isolation in any application.
In addition, it is important to note that the main connector body connects to the cable shield when the cable is plugged into the device. The cable shield is separate from the power return potential and since the connectors are isolated from the body, the user can attach it to any potential using the shield of the cable.