Hi Eran,
I am not sure on the reason why you want to set restrictions to ES30 tcode. ES30 is only used for installations and in IS, only three installations are created: water, sewer and fire services as per my knowledge.
The process is simply repeated three times with the changes documented in the table for each installation and further you should enter the key specified. It will not allow you any other keys to enter.
If I didn't answer your question correctly, please post with more information on what exactly you are looking to restrict. Also, provide the object information for ES30 transaction code.
Rgds,
Raghu
