In article ,
PoP writes:
This use of a UPS raises a query in my mind. Isn't there a set of
regulations covering computer room supplies? Maybe that just applies
to computers on the circuit though.

There are rules relating to UPS's and generator sets.
Earthing them properly is a rather non-trivial task.
You aren't allowed to assume an earth provided by your
electricity supplier is still working when the supply
fails.

--
Andrew Gabriel