Earthing systems

[eejacky]

I know there are a number of earthing systems including TT system, TN system and IT system. However, I wonder why different countries use different systems. Is there any reasons for that or each system has its own advantages or disadvantages?
I hope experts can give me information on these.

 

[jbartos]

Suggestion: There are major differences between system groundings. Major factors are:
1. Whether or not the power distribution type permits it.
2. Whether of not there is an expensive process downstream that does not have to be disrupted by a single ground fault.
3. Local power distribution standards.
4. Cost.
5. Advantages and disadvantages of each of system grounding approaches.

 

[busbar]

Economics primarily, but also safety and history [and their perceived economic impact] seem to be the major influences in variations of system grounding.