Quote from: philipma1957 on February 02, 2019, 06:57:49 PM

My input is 243.1 and my output is 220.7 on my hand held meter
the meter on the unit read 243 in and 220 out.

I was looking at a Larson Buck transformer to change the 240 at my house to 220 or 208 so I could run a couple of S15's at home, but it's not really cost effective. Also, they show a 3-4% loss of efficiency in the windings due to heat loss. I don't think you can step down the voltage with any device and not experience a certain small loss in the process, so keep that in mind when calculating the cost to run an S15 vs say an M10. With a transformer an S15 might end of drawing 60 or more w/per TH. It would be great if Phil could test that on his device.

We now have 28 S15's running on the rack at the office now on 208v, and they are functioning perfectly. They are all 28TH units. The min to min hash rate variance is higher than spec, can be up to 15% either way, but the daily average of the units collectively is 783.9 TH which = 783.9 which is 27.96TH per machine on average, so they are running exactly within spec on our 208v supply. Power draw is averaging 1590w per unit. That's based on the total draw on our panel. I haven't measured individual units. We're using Triplite 3' 12awg power cables from the PDU to the units. One miner per PDU circuit, 2 miners per PDU so the breaker on the PDU's become the power switches. The 12awg cables are to minimize loss more than anything else, I don't think we would have any trouble using 14awg cables for these as long as they are short. This is all equipment reused from the S9 farm.

Bitmain replaced our 2 units that failed on 240v+ for us under warranty. One of the replacement units came with the 'open power rail' design (which bothers me greatly). All the other have the power rail covers.

Oh, also, the DHCP network problem we had with the 2nd batch of arrivals was unique to that batch, 6 machines. We had to plug those into a small router and scan for the IP address, then change the settings to a static IP on our network. All of the new arrivals come up on our network fine at boot.