said by Hagar:I am a curious person and have lived in many places in the world. Some of them did not have a neutral to ground connection in the main panel. Maybe they had a connection upstream at the pole. The last place I saw no neutral ground connection had a whole house GFI. One lab I visited had two grounds, regular ground that was connected to neutral and reference ground that was not.
It would be a mistake to think that all power distribution systems around the world are the same as the system used in the United States. As you list your location as Sunnyvale, CA; I based my response to your question on the system used in the US. That by no means should imply that all electrical systems have the neutral and ground bonded as is required with our system.