hi guys
so if i want to calculate the three phase capacity of my warehouse i should consider that each s9 need 1350 watt and the PSU capacity should be 660 watts???
Watts are watts. A 50W light bulb pulls 50Ws if run at 12V (~4.2 amps), 110V (~0.45 amps), or 220V (~0.23 amps). Because of the lower amperage draw at higher voltages, thinner wire can be used to carry the current.
e.g. If your running a 1350 watt device, you need at LEAST a 1350 watt power supply/power supply efficiency. For example: if your power supply is 80% efficient (cheap and bad!), it would need to have 12V rails rated at 1350/.80 = 1688 watts and would be running at 100% utilization then, wasting (and generating heat for) 338 watts of power. At 93% efficiency (APW3++), that math works out to 1452 watts with a waste of only about 102 watts. You also need to check the efficiency curve for the power supply, since "efficiency" is often quoted at the optimal power draw for that device.
From the Bitmain page: Power Consumption 1127W (11.5TH/s batch), 1225W (12.5TH/s batch), 1274W (13TH/s batch), 1323W (13.5TH/s batch), 1372W (14TH/s batch) (at the wall, with Bitmain’s APW3 PSU,93% efficiency, 25°C ambient temp). Expected discrepancy of +10%
The above statement from BitMain is either miss-leading, or lost something in translation. At 0.098J/GH, a 13.5TH machine would consume 1323W JUST FOR THE CHIPS. Their comment to add 10% however should compensate for the fans, controllers, support logic, and power supply inefficiency if your running one whose sweet spot is near 1350 watts at 93% efficiency, like the APW3++ is.
Regarding 3 Phase power, unless you have a 3 Phase power supply (VERY unusual), that 3 Phase power is likely just going to be broken into 3 single phase distributions. Your challenge is to keep the load balanced across those distributions.
