Generator earth

[lyledunn]

In a simple one-liner, what would you regard as the "main" reason for tying the star point of a 400v 4-wire generator to earth?

Regards,

Lyledunn

 

[alehman]

It depends on the system. Two reasons for grounding low votlage systems: 1. to provide ground fault current to operate circuit breakers; 2. prevent transient overvoltages in the event of an arcing fault.

 

[RRaghunath]

I think it is more to do with human safety.

 

[DanDel]

To provide a consistent reference to ground.

 

[buzzp]

The better phrase might be why wouldn't you tie the center point to ground?

 

[Rodmcm]

Normally you are legally obliged to have a power system neutral connected to earth. This is for safety reasons and also to stop high voltages being induced on insultated systems that may break down. However, if there is more than one source of power then it is not uncommon to have only one earth rather than multiples. Earthing of generators with and without other sources is a big topic

 

[jbartos]

Comment: 400V, 3-phase, 4-wire supply is a multivoltage system; therefore, the solidly grounded neutral system grounding is applicable only. The multiple sources of this kind are required to be solidly grounded by electrical safety code(s). If some of those sources stayed ungrounded and their neutral applied, there may develop current loops among sources with circulated currents; especially, when some unbalance load conditions exist.