Grounding of Isolated Gen. Sets

The qualified Electricians who will install them can work all this out using the local electrical codes: in India, IS3053, in the UK, BS7671, etc.

Cables need to be sized to carry fault currents safely, for which local advice must be sought based upon the design detail and observations of the proposed installation.

If in doubt, consult a qualified Electrical Engineer locally.

That may work but it will depend on the local electrical standards and codes that are applicable to where the factory is. Also, a single ground electrode may not be enough (the resistance could be too high), but again you need to check your site and standards.

Where is the factory?

??

LOL

Since these generators are not interconnected in any way, I would be inclined to view them as 4 separate installations with their own earth stakes and neutral bonds as per local regulations. Ground fault currents will be specific only to the affected source.

By all means bond them to the metal structure as required and install RCD protection where possible.

You will need to check local regulations regarding safety control of all generator outputs for safe isolation in the event of an emergency.

Thanks all! What I think is that connecting grounds of all gen set together without synchronizing them would cause fault current in to flow in all gen sets if it there is a fault at any generator.