Started day 5 sequence of 5 day endurance test, temporarily lost commercial power at 8:00. Generator responded and we continued running seepage pump , trash rake and conveyor. At 10:40 we tested emergency stop. At 12:48 we lost commercial power . Followed by a surge that tripped the main . Scott tested the main and found that phase B was at 396 volts as opposed to 277. Generator ran the seepage pump , trash rake and conveyor the rest of the day. 
Glades Electric stayed a blown fuse further up the line caused the outage and the over supply of power . It also blew an arrestor in our transformer . Power was restored around 3:30 . I ran thru all equipment and made sure nothing was offline . 