The ring breaker has been changed for another 30A and it still tripped
either itself or the main - the ring breaker has also been upped to a
40A

Did you, or anyone else, calculate whether the wiring is suitable
for this first?


What calculation would that be ? - I've simply exchanged a suspect 32A
breaker for a known good 40A one as part of a process of ellimination -
the same issues were found so i changed it back.

I have 4 TFTs - no CRTs - a small laser printer and couple of
hub/routers + a max of 8 workstations.

I normally use the soft start buttons to power up - therefore all of
the internal PSUs are being fed from the ring but taking no real load -
very often i have all workstations running without issue and can turn
on/off via soft start without tripping yet at times even if i just have
a couple connected to the ring it blows.

Looks like a non RCD ring + indivdual on/off for each workstation is
the way to go ?