Quote from: philipma1957 on March 07, 2019, 07:56:10 PM

well remember only 1 person has had confirmed psu death at 243-247 volts

I would love to know if someone else has had this happen.

That was me. I tried 2 units at home back in January on separate 30amp 240v circuits, one in my basement and one in my garage. These are circuits I ran S9's on all last winter. Both S15's PSU's failed or fault tripped resulting in no power at slightly above 240v. My multimeter tests those circuits around 240.8v on average but they can vary +/- a couple of volts. One S15 failed almost immediately, within an hour, and the other ran for around 10 hours before crapping out. Both PSU's were noticeably hot prior to failure. I suspect the basement unit failed first due to the ambient (around 60f) being warmer so it over heated more quickly. The garage unit ran longer (ambient around 25f). Both units were returned to Bitmain CA under warranty repair tickets and were replaced directly from China in about a week.

We currently have 43 S15's running at the commercial farm on 208v, some for nearly 2 months, without any failures or issues though we did get one unit that had a bad hash board. Bitmain also replaced that unit under warranty in about a week.

I would not attempt to run anymore units at close to 240v without a step down transformer. Other than that, they have turned out to be fine gear. I have no complaints. They are all 28th/s units. Collective average for 43 units is 1.2Ph, so all machines are running very close to spec at 208v and 50-60f ambient mining room temp. Curious to see how well they hold up a couple of months from now once our mining room starts to get hot. We do intend to switch them into LP mode once the ambient starts getting into the 90's and mine them like that during the course of the summer.

One note - all 3 of our warranty replacement units seem to have come out of China stock and do not have the power rail covers, they are the open rail design. All other units we received have the rail covers.