Symetra 250 KVA UPS bypass module

[BillP]

On Friday the APC Tech  was replacing the bypass module on our UPS that failed,  from a 250 KVA to 500 KVA because APC did not readily have available a 250 KVA module and on the log on 10/30/15 at 8:56:26 the whole system powered done when he flipped the Q3 breaker back on and we lost half of our Data Center. What caused this event and what can we do to prevent it in the future. if needed i can be reached by email at kuchar.matthew@mhsil.com. Thanks for all your help.