In our homes one side of the outside distribution system is grounded, and so likewise inside. And that distribution system often runs on poles with much higher voltages, so keeping our voltage close to ground is for safety.

 

In our homes one side of the outside distribution system is grounded, and so likewise inside. And that distribution system often runs on poles with much higher voltages, so keeping our voltage close to ground is for safety.

Also true, but does not mean a 120 volt vehicle system should float.

 

Actually, the European system where the center tap of the 240 volts is tied to ground and no current-carrying neutral is used,

Where is that used in Europe?
The British system is a 1 phase of a 3ph transformer with the star point neutral earth grounded.
Max.

 

Also true, but does not mean a 120 volt vehicle system should float.

I never suggested that in our home systems, which do not have an isolated power supply, that they should be floating. My original assertion is that in a system that has an isolated power source that is not ground referenced in any way, that there is not any real benefit from intentionally grounding one side of the supply.
The only theoretical benefit given so far is that one side of the isolated power system might become grounded, leading to a shock hazard from the other side. That presumes that users would randomly connect with one or the other sides of the power pair, which most folks would tend to avoid doing.

 

Where is that used in Europe?
The British system is a 1 phase of a 3ph transformer with the star point neutral earth grounded.
Max.

That implies that neither side of the 240 volt line in the UK power system is grounded, and that therefore both sides have a 120 volt shock potential. Is that correct??

 

No. the 230v is a derived from a 390v 3ph transformer using one phase resulting in a single phase 230v WRT the star point neutral of the transformer which is taken to earth ground.
The 3ph transformer feed a number of residences per each phase.
Max.

 

No. the 230v is a derived from a 390v 3ph transformer using one phase resulting in a single phase 240v WRT the star point neutral of the transformer which is taken to earth ground.
Max.

Thanks, Max,That makes sense. It also means that one side of the source is at ground. Similar to the USA, except that we have 120 volts to ground and 208 volts between phase ends. And given how uncomfortable a 120 volt shock is, a 220 volt shock must really hurt.

 

My first one was the two (live) conductors, one in each hand!
N.A. is pretty much Universal now.
Max.

 

My first one was the two (live) conductors, one in each hand!
N.A. is pretty much Universal now.
Max.

Just look up the electrical code for campers and RV's with 120 volt generators!

 

RVs and Camper vehicles are quite different from autos in that they often plug into mains power. And having a generator is no assurance that one of them will not hook up to mains if it can.