When you say it shuts down, exactly what are you noticing that makes you think its shut down? Is the PSU's fan stopped? Are the miner's fans running? Is the PSU hot to the touch? What type of mains circuit is it on?
Thanks for fast reply dogie,
When Shutdown happens, PSU fan stops and miner's fan also stops simultaneously. PSU is warm but not hot that someone can't touch it.
It is on 230 V circuit ,dedicated line only for miners rated for 16 Amps , total Load is less than 3000Kw, Irony is my other gigabyte PSUs which are 3 year+ old still run smoother.
May I try Low frequency setting (less than factory 600)? so it can be checked that Enermax PSU of S7 LN is not overloaded