Hello,

I'm hoping to get 75 S9's in my garage. I'm planning all of this out and am trying to figure out how many amps I need to support that. Is it right I'd need almost 500 amps to my garage to support all 75 S9s?

I'm very confused on this math because I've seen many posts that say 400 amps support up to 100 S9s but that doesn't jive with what I'm calculating what I'd need.

Thank you!

There are a LOT of post explaining this, but one more time, in round numbers:

Frequency * power consumption / joules per GH = chip power consumption

chip power consumption / power supply efficiency = 12V power drain, shy a bit for fans, the controller, etc.

wattage / voltage = amps (remember Ohm's law???)

breakers should never be continuously loaded for more than 80% of their rated capacity

wire should always be rated at the breaker rating (or larger, but nobody commonly does that)

so:

13500 MH* 0.098 J/MH = 1323 watts (just like the Bitmain page says)

1323 watts / 0.93 efficiency = 1422 watts, call it 1450 with fans an controller for this exercise

1450 watts / 220 volts = 6.6 amps

20 amp breaker allows you to use 12 gauge wire, which is easier than 10 gauge if you opt for 30 amp breakers

20 amps * 0.80 = 16 amps allowable per breaker

Therefore: You can put 2 miners on a 20 amp 220V breaker

(75) S9s would require (38) 20 amp 220V breakers.

A 200 amp breaker panel has a 200 amp master breaker at top. 80% rule applies to that too, so 160 amps total usable per panel.

160 amps / 6.6 amps (which is pushing it to the limit) = 24 miners per panel or (12) 20 amp circuits, but...

A typical 200 amp indoor main breaker panel has 30 spaces, 60 circuits, 15 spaces per side. Each 220V breaker requires 2 spaces, so you can only get (7) 220V breakers in per side, but that would overload the panel since 7 per side = 14 breakers = 28 miners = 185 amps which is greater than the limit.

You can find 20 space, 40 circuit 200 amp panels that work out better: 20 spaces = 10 breakers = 5 per side. 10 breakers = 20 miners = 132 amps which is comfortably below the 160 amp limit.

Using those 20 space panels would mean you would need (4) such panels. To power them, you would need 75 * 6.6 = 495 amps of continuous draw power spread between those panels.

That is excluding power for lights, fans, etc. (not to mention the rest of your house)

Then there is the minor problem of getting rid of 1450*75 = 108,750 watts of waste heat, but that is a different discussion.

Oh, and dealing with the noise.

Moderator: if you are willing, could you Pin this?